ANATOMY
Anatomy Study Guide Block 1(Main Points Covered)
http://classes.kumc.edu/sah/resources/andersen/Anatomy-General-2011/
BLOCK 1
June 1 (Lectures 1-3)
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Gross Anatomy overview
o Anatomy: literally means to cut apart, originally referred to study of structure of human body through
dissection. Early primarily descriptive no functions
o Gross Anatomy: study of structures observed without the aid of magnification
o Histology/microscopic anatomy: viewing anatomy at a microscopic level
o Developmental Anatomy: structural changes that occur in organ systems as they develop
o Neuroanatomy: study of the nervous system in detail (gross, developmental, microscopic)
o Morphology: the study of form, encompasses al sub-disciplines
Know anatomical postion
Planes and Axes
o Cranial-Caudal: vertical line, running straight down/up from head to tail, perpendicular to floor
o Dorsal Ventral: running anterior to posterior, stomach through back, parallel to the floor
o Left-Right: side to side, parallel with the floor
o Sagittal Plane: plane is made up of the cranial caudal axis and the dorsal ventral axis
 Elbow flexion extension is in a parasagittal plane
o Frontal Plane: made up of the left right axis, and the cranial caudal axis
 Abduction, adduction
o Transverse Plane: made up of the left right axis and the ventral dorsal axis
 Rotational movement in this plane
General Terms (review all, only ones not familiar typed)
o Ipsilateral: on the same side of the body
o Contralateral: on opposite sides of the body
o External Rotation (transverse plane)
 Upper limb: a movement of the shoulder joint that the anterior aspect of the arm (bicep) moves
away from the body
 Lower Limb: a movement the anterior aspect of the thigh moves away from the body
o Internal Rotation (transverse plane)
 Upper limb: a movement of the shoulder joint that the anterior aspect of the arm (bicep) moves
toward from the body
 Lower Limb: a movement the anterior aspect of the thigh moves toward the body
Skin
Epidermis: stratified squamos epithelium, outmost layers in contact with environment are flattened shape
 Avascular, innervated
 All nutrients pass through basement membrane from dermis to epidermis
o Stratum Germinativum: deepest layer of the epidermis, cells in this layer are constantly dividing, daughter
cell products of the mitotic activity are pushed toward the surface
 As cells move further away from this layer, do not get nutrients and die
 Before dying cytoplasm is replaced by keratin
o Stratum corneum: outermost layer of dead keratinized cells
Dermis: dense is histologically described as a dense irregular connective tissue, tough protein in irregular bundles
o Made of collagen with varying amounts of elastic fibers (as age increases elasticity decreases)
o Fibrocytes: secrete and maintain the collagen fibers
o Dermis is vascularized with a capillary plexus located just below the basement membrane
Skin Thickness
o Thick skin: 5 layers of cells in epidermis, no hair growth, palms of hands and soles of the feet
o Thin skin: 4 layers of cells in epidermis, found everywhere else in the body
 Thinnest is on the eyelids
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 Thickest is found on the back
 Thicker on the extensor surfaces than the flexor surfaces
Superficial Fascia (subcutaneous tissue)
o This fascia consists of loose bundles of collagen, elastic fibers and may often be the site of large
aggregations of lipocytes
o Contains and supports cutaneous nerves and blood supply
Deep Fascia
o Usually consists of several thin layers of tough collagen material covering and tightly adherent to underlying
muscles and other deep structures
Cutaneous Structures
o Glands: derived from the epidermis and grow down into the dermis, where they are supplied by the blood
vessels and nerves of the dermis
o Glands frequently grow down from an epithelial surface into a connective tissue layer
o Exocrine Glands: retain connection to epithelial surface, secrete their product to that surface
 Sudoriferous (sweat glands), sebaceous (oil), mammary
o Endocrine Glands: glands that lose their connection to the epithelial tissue and secrete into capillaries,
produce hormones
o Sudoriferous gland: primary purpose to carry water onto epidermis to evaporate
o Sebaceous glands: oil producing glands that are found associated with hair follicles
o Mammary glands: modified sudoriferous glands with apocrine secretion
 Lose apical end as part of secretion, but retain basal end and cell regenerates
Hair Follicles
o Develop during the third month, first hair called lulogos
o 95% of males covered in vellus hair
o 35% of females covered by vellus hair
o Hair growth
 Anlagen = active hair growth
 Growth occurs in the matrix where cells divide, daughter cells are pushed upwards within the
follicle, as they progress further away from matrix lose nutrients and become keratinized (much
like stratum germinativum
o Around the matrix of the growing hair is a nerve plexus, this is sensitive to hair movement, so hairs can be
used as a sensory receptor
o Hair found everywhere except palms, soles of feet, dorsal distal phalanges, and apertures
Nails
o Modified corneum, flattened, avascular, not innervated, travels the entire nail bed
o Has a matrix (stratum germinativum), produces ungus, if lose nail but not matrix nail will regrow
Melanocytes: pigment, found in deep layers of the epidermis, derived from nervous system components,
o Melanosomes passed off to keratinocytes, which phagocyte melanosome
Langer Lines: mainly used by surgeons, tension lines created by the orientation of collagen fibers in the dermis of the
skin
Dermatomes: a specific region of skin innervated by a specific spinal cord level
Functions of Skeletal Tissue
o Help body resist the pull of gravity, protect organs, provide attachments for muscles/tendons, movement
o Major repository for calcium and phosphate
o Houses blood forming tissues,
Fibroblast: cell which secretes collagen and other fibers
Fibrocyte: cell which maintains the fibrous matrix in which it is embedded
Chondroblast: cell which secretes chondroitin sulfate (cartilage)
Chondrocyte: cell which maintains the chondroitin sulfate matrix in which it is embedded
Osteoblast: cell which secretes bone matrix
o Secretes calcium carbonates and phosphates which make hydroxyapatite
Osteocyte: cell which maintains bone matrix in which it is embedded
Osteoclast: cell which destroys bone matrix, releases calcium salts
Tendons and ligaments: both are formed from dense bundles of collagen fibers
o Few nerves and blood supply enter these substances which makes healing these structures when they are
injured, scattered among the collagen fibers are fibrocytes
Hyaline Cartilage (used in mainly movable joints)
o Cartilage matrix is secreted by chondroblasts, collagen surrounded by proteoglycans
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Bone
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The surface carries many negative charged molecules so that they repel the rest the molecule and thus try
to occupy a larger volume
 Pressure will reduce the volume, but the electrostatic forces repel
Chondrocytes maintain the matrix and lie in lacunae, but they began as chondroblasts
Cartilage is slow to heal, is avascular, oxygen and nutrients diffuse in
Normally about 35 percent organic and 65 percent inorganic (hydrooxyapatites)
Trabeculae (cancellous bone): bone matrix organized into a network of irregular shaped bony rods
Lamellae (Compact): layers of bone matrix
Osteon: consists of several lamellae arranged concentrically around a Haversian Canal (carries nutrients)
Lacunae (bone): osteocytes are housed here in the bone matrix (same as cartilage)
Bone cannot diffuse so they must have canals to supply blood to bones
Canaliculi: connecting the lacunae within an osteon with each other and with the Haversian canal itself, tiny
radiating canals
Volkmann’s Canals: connect Haversian canals, run perpendicular to the long axis of the bone
June 3rd Lecture (end of Lecture 3-Lecture 5)
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Osteogeneis
o The cartilage in a baby is replaced by bone, it is NOT transformed into bone
o Mesenchymal cells tend to become clustered in elongated groups, which secrete a strand of delicate
collagen fibers
o Osteoblast will used collagen fibers as a framework and deposit hypoxyapatite (ossification), once fiber of
collagen is completely ossified it is called a trabecula
o Bone formed with original mesenchyme is called spongy bone
o Periosteum may form on either side of spongy bone and osteoblasts in this layer will lay down compact
bone
Endochondral Bone Formation (starts in diaphysis)
o Occurs within a hyline cartilage model that is shaped somewhat like the future bone
o Avascular cartilage becomes vascularized, which brings a supply of osteoblasts and breaks down the
cartilage matrix
o Cartilage matrix reduced to a honeycombed network, the matrix is then covered in calcium salts
(calcification not ossification)
o Once calcification is complete, the osteoblasts begin to ossify the strands forming a trabecular frame
o While spongy bone is formed, periosteum is laying down layers of compact bone to form a bony collar,
bones carry load in their walls, not their center
 This process begins to increase the diameter of the bone
 Increase in diameter is caused by increase in bone growth, beneath the periosteum
o Addition ossification occurs at the ends of the bone forming epiphyses
 During this osteoclasts breakdown ossified center of bone to create a hollow cavity
o Plates of cartilage are left between the areas of ossification (epiphyseal plates, i.e. growth plates)
 When bone grows faster than cartilage the growth plates disappear
 Bone growth in length must occur interstitially due to formed articulations and muscle
attachments
 Bone cannot grow interstitially, but cartilage can therefore the growth plates importance
Joint Classification
o Cartilaginous: slightly movable
 Synchondrosis: epiphyseal plates at the end of long bones, formed of hyaline cartilage and holds
two bones in close proximity
 Symphysis: bones held together by fibrocartilage, pubic symphysis and intervertebral discs,
generally only very slight movement
o Fibrous Joints: has little mobility, formed of dense collagenous tissues, with varying amounts of fibroelastic
tissue
 Suture: have irregular edges that interlock, with a fibrous membrane that holds the bones
together, joints between bones of calvaria (skull)
 Gomphosis: a peg in socket type of joint, teeth
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Syndesmosis: interosseous membranes that hold two bones together, tibia and fibula, or radius
and ulna
Synovial: a joint that is designed for mobility
Every synovial joint has a close packed and loose packed position
 Close packed: ligaments tight, joint extension, more stable, BUT more likely for injury
 Loose packed: ligaments loose, joint flexed, less vulnerable, BUT less stable
 Hiltons law: blood supply that runs over a joint, generally will supply the joint
 Has articular cartilage on each end of the joint that covers the surface of the bones creates a low
friction area
 Entire joint surrounded by a joint capsule, ligaments, Sharpey’s fibers, and synovial fluid
 Joint Capsule: outer cover is fibrous and innervated
 Inner synovial fluid is not innervated but it is vascularized
 Uniaxial Joints
 Hinge Joints, interphalangeal joints, and pivot joints
 These joint allow for movement in only one plane
 Biaxial Joints
 Condyloid or Ellipsoid: a concave surface fits over a convex surface, metacarpalphalangeal joint, allows for extension/flexion and ab/adduction
 Saddle Joint: specialized joint in which both surfaces are saddle shaped, only the thumb
 Triaxial Joints
 Ball and Socket: movements allowed in all three planes, extension/flexion, ab/ad, and
rotation
 Non-Axial: consist of two relatively flat surfaces which slide over one another
Lecture 4 (June 3)
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Tendons: bundles of collagen fibers with very little matrix, and are surrounded by membrane called peritendineum
(similar to periosteum)
Aponueroses: flattened, expanded tendons (palmar and planter)
Structural Hierarchy
o Myofilament: thick filaments (myosin) and thin filaments (actin)
o Myofibrils: bundles of myofilaments, arranged by segments into sarcomeres
o Myofibers: considered and actual muscles cell (multinucleated) and made of many myofibrils, covered by
the sarcolemma and endomysium
o Fascicle: bundles of myofibers, covered by the perimysium
o Muscles: composed of several hundred fascicles covered by epimysium
o Epimysium: makes up part of the body’s deep fascia, provides physical support and a pathway for nerve and
vessels
Myofilaments
o Actin: filamentous protein arranged in a double helix, also includes troponin and tropomyosin
o Myosin: composed of long molecules composed of protein, consists of a long tail with a globular head and
ATPase activity (breaks down ATP)
o Sliding Filament Theory
Sarcomere Organization
o Z-actin: actin is anchored into plates that are perpendicular to the long axis of the myosin and actin
filaments
o A-Band: contains both actin and myosin Each consists of a dense middle band made up entirely of myosin,
this band does not change in length as the muscle contracts
o I-Band: completely actin, the actin filaments are thinner, these bands appear less dense, from the end of
myosin on one sarcomere to the beginning of myosin on the next band
 This band shortens during muscle contraction
o H-Band: composed only of myosin, this band completely disappears during muscle contraction as actin
slides through this area
o When the myofibrils in one fiber contract the entire fiber contracts, when one sarcomere contracts all
sarcomeres contract
o Sarcoplasm in contact with sarcolemma by way of T-tubules, these tubules help conduct the action
potential, when the potential reaches the T-tubule calcium is releases which allows the muscle to contract
o Cisternae: where the calcium is stored in the sarcoplasmic reticulum
Fiber Types
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All myofibers in a single motor unit are all of the same type
Dark (Type 1 Fibers): slow twitch fibers that rely on oxidative phosphorylation, fatigue resistant, have a high
number of mitochondria, have a high concentration of myoglobin (bind oxygen), and have a lower
concentration of ATPase
o Light (Type 2 Fibers): fast twitch, rely on glycolysis, do not have as many mitochondria or as much
myoglobin, more ATPase, fatigue more quickly, less myoglobin makes these muscle lighter colored
Neuromuscular Junctions
o Made up of three parts (pre-synaptic membrane, synaptic cleft, and the post synaptic membrane
o All or none principle: if a motor neuron or motor unit fires all the fibers innervated by that fiber will fire
 This does not mean that the entire muscle will fire, just that motor unit
 Motor units needed for fine movements may only have a few myofibers
 Gross movements may have hundreds of myofibers per unit
Muscle Shapes
o Fusiform: bicep brachii, wider in the middle but running to a point at one end, see picture on 35
o Unipennate: muscles which have fibers running in an oblique direction on one side of a tendon
o Bipennate: muscles running in an oblique direction on both sides of a tendon
o Multipennate: many tendons with oblique fibers running different directions
Muscle Contraction
o A muscle contraction is a response to a sensory stimulus
o Isotonic: tone does not change in a muscle, but length does change
 Concentric: shortening of a muscle
 Eccentric: tone stays the same but the muscle lengthens
o Isometric: muscle length stays the same but the tone changes
Recruitment: because of all or none and motor unit innervations, we can recruit certain parts of a muscle but not the
entire thing
o Example of cup of coffee or screw driver
o Able to recruit some fibers for finer control (all or nothing means we recruit all of one motor unit, but not all
motor units fire), for gross movements we recruit all fibers
Types of Actions
o Agonist: the primary mover in any movement
o Antagonist: the opposing muscle in a movement
o Synergist: a muscle that eliminates the unwanted action of the agonist
o Fixator: a muscle that stabilizes the origin of another muscle
Insufficiency
o Refers to the inability of a mulitjoint muscle to maximally contract simultaneously over all joints crossed
 Active: refers to the agonist, usually unable to cause maximal shortening over all joints crossed
 Passive: refers to the antagonist, usually cannot lengthen completely over all joints crossed
o Example of squeeze fist and curl biceps, biceps curl completely but fist is not as strong as without curl
Smooth Muscle: no striations, visceral, involuntary, associated with hair follicles, around glandular structurs, in walls
of blood vessels, walls of visceral tubes
o Bundles of sheets of individual cells, not striated, cells are primarily elongated and tapered, mononucleated
o Nuclei centrally located, no action potentials, cells connected by gap junctions, no voluntary
Cardiac Muscle
o Found only in heart, striated, mononucleated, connected by intercalated discs
Lecture 5 (June 3) CNS, PNS and Typical Spinal Nerve
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Functions of the Nervous System
o Sensory: functions referring to the carry of signals from the surface of skin, muscles, tendons, and from
internal organs, these signals provide brain with information in order to provide response
o Motor: carrying of signals from the CNS to the muscles and glands
o Cognitive: processing of information within CNS and higher brain function
o CNS: brain and spinal cord, unpaired, bilaterally symmetrical structures extending along the longitudinal axis
o PNS: nerves specialized sensory receptors, and specialized motor endings
 Carry info between the CNS and external/internal environments
 Afferent: carry information to the CNS
 Efferent: carry information from the CNS to the body
 12 pairs of cranial nerves and 31 pairs of spinal nerves
ANS: sympathetic and para-sympathetic
 Entirely motor, innervates smooth muscle and glands, in charge of involuntary
 Sympathetic: fight or flight
 Para-sympathetic: feed and breed, opposes the sympathetic
 Sympathetic: preps body for a stressed situation, increase in HR, breathing, dilation of pupils, hairs
stand on end
 Para-sympathetic: HR goes down, breathing down, digestion up
 Basic Structural Unit of the Nervous System
o Cell Body: the site where the nucleus and other cell organelles are located
 Does not undergo mitosis, needed to maintain and repair the rest of the neuron
o Dendrites: short branches that radiate off the cell body, vary in number based on type of neuron
 they carry receptors for neurotransmitters and are a common receptor site for incoming signals,
conduct local potentials
o Axon: part of the neuron that carries info to another neuron or muscle, usually relatively long, single,
conductions action potentials
 Contain mitochondria, neurofilaments, and neurotubules
 Always covered in Schwann cells, but some axon have a myelin sheath for conduction
 Large diameter and myelin sheath axon are the fastest
 Neurotubules: act as a monorail system for repairs
 At the end of the axon (telodendria and terminal buttons) are vesicles that release
neurotransmitter when the action potential has been reached
 Basic Neuron Physiology (review lecture notes)
 Terminology
o White Matter: consists entirely of myelinated axons
o Grey Matter: unmyelinated, cell bodies, and dendrites
o Anterograde: information travels down the axon
o Retrograde: information travels up the axon
o Nucleus: an aggregation of dendrites and nerve cells in the CNS
o Ganglia: an aggregation of dendrites and nerves cells in the PNS
o Nerve: bundle of axon in the PNS
o Tract: bundle of axon in the CNS
o Commissure: tract in the CNS that crosses from side to side
 Spinal Nerve Branches
o Dorsal Primary Ramus: carry sensory fibers from the dorsal surface of the body on either side of the midline
and motor fibers to the deep back muscles
o Ventral primary ramus: larger in diameter and longer, carries sensation from every excepts dorsal surface,
and supplies all muscles except the deep back
 Reflex Arc
o Afferent pathways: somatic and visceral
o Efferent pathways: somatic and visceral
o Association neurons: one or more neurons interposed between the sensory neuron and motor neuron
 Confined to the CNS and serve as sites where info processing occurs
 Pathways with these neurons are polysynaptic
 ANS
o Paravertebral ganglia: found on either side of the spinal cord, forming a long chain of interconnected
ganglia
o Pre-vertebral ganglia: in the abdominal region, specifically named for aortic branch
o Intra-mural ganglia: found within the muscular walls of viscera
June 6 (Lectures 6-8)
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Mammary Gland
o Modified sweat glands, 15-20 glands, lobes separated by fibrous septa, lactiferous duct (1 per lobe),
lactiferous sinus, extend from 2nd-3rd rib to 6th to 7th rib, lateral border of sternum to beyond the anterior
axillary fold
o Fibrous tela subcutanea: connective tissue surrounding the entire gland
o Fatty tela subcutanea: adipose tissue deep to the fibrous layer
o Suspensory ligament of Cooper: bundles of collagen fibers in dermis and hypodermis
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Mammary gland sits on top of pectoral fascia and pectoralis major, if breast cancer the cancer can go
deep into the pectoralis major
 Space between the mammary gland and pec major called retrommary space
o Arteries
 From internal thoracic artery to medial part of the gland
 Medial mammary rami: to deep medial part of the gland
 Lateral Mammary artery: from lateral thoracic artery to inferior of gland
 Lateral mammary rami: lateral cutaneous branches of intercostals to lateral part of gland
o Veins
 Superficial and deep venous plexuses
 Internal thoracic, lateral thoracic and intercostal veins
o Nerve
 Lateral mammary nerve (T2-T6)
 Lateral cutaneous branch of intercostals nerves
 Medial mammary nerve (T2-T6)
 Lateral branch of anterior cutaneous branch of intercostals nerves
o Lymph
 Perilobular and interlobular into subareolar plexus, to lateral lymph trunk, medial lymph trunk, to
pectoral group of axillary lymph nodes, to subclavian lymphatic channels
Thoracic Wall
o Muscles
 Platysma: thin sheet of muscle that runs from the face down to the tops of the clavicles, other than
for grimacing this muscle goes mostly unused
 Pectoralis major
 Origin: anterior surface of medial half of the clavicle (clavicular head), anterior surface of
manubrium and body of sternum, costal cartilage 2-6, and aponeurosis of external oblique
(sternal head)
 Insertion: crest of the greater tubercle of humurus (lateral lip of bicipital groove)
 Action: adduct arm, internal rotation, (clavicular head helps to flex the humerus)
 Innervation: clavicular head = lateral pectoral nerve (C5,6)
o Sternal head = medial pectoral nerve (C7,8, T1)
 Pectoralis Minor
 Origin: ribs 3-5
 Insertion: medial border of the corocoid process
 Action: draws scapula forward and downward, elevates ribs if scap fixed, and assists in
respiration
 Innervation: Medial pectoral n. (C8 and T1)
 Subclavius
 Origin: junction of rib1 and its costal cartilage
 Insertion: inferior surface of the middle third of the clavicle
 Innervation: nerve to subclavius (C5,C6)
 Action:depress lateral end of the clavicle
 Serratus Anterior
 Origin: ribs 1-8
 Insertion: costal surface of scapula, medial border of scapula,
 Action: protracts scapulas, upwardly rotates scapula, holds scapula to chest wall to
prevent winging (stabilize)
 Innervation: long thoracic (C5-7)
 Latissimus Dorsi
 Origin: Spinous process of T7-12, spinous process of lumbar spine, thoracolumbar fascia,
iliac crests, and ribs 9-12
 Insertion: floor of the intertubercular groove (bicipital groove)
 Action: extends arm, adducts arm, and internally rotates arm
 Innervation: thoracodorsal n. C6-8
 Trapezius
 Origin: upper fibers: external occipital protuberance, superior nuchal line, ligament
nuchae, and spinous process of cervical vertebrae 7
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o Middle fibers: spinous process of T1-T6
o Lower fibers: spinous process of T7-12
 Insertion: upper fibers: lateral third of clavicle
o Middle fibers: acromion and crest of scapular spine
o Lower fibers: tubercle of scapular spine
 Action: upper: elevate scapula
o Middle: adducts scapula/retraction
o Lower: depress scapula
o ******************** middle and upper will upwardly rotate scap
 Innervation: accessory nerve cranial nerve 11
 Rhomboid Major
 Origin: spinous process of T2-T4
 Insertion: medial border of the scapula
 Action: adductions scapulas, retraction, rotates glenoid fossa downward, fixes scapula to
the thoracic wall
 Innervation: dorsal scapular never (C5)
 Rhomboid Minor
 Origin: C7,T1
 Insertion: superior angle of the scapular, medial border
 Action: adduction scapula
 Innervation: dorsal scapular nerve C5
Deltopectoral Triangle
o Boundaries: Superior border of pectoralis major, medial border of deltoid, and clavicle
o Contents: Cephalic vein, deltoid branch of thoracoacromial artery, and deltopectoral lymph nodes
Clavipectoral Fascia
o Invests subclavius and pectoralis minor
o Pierced by cephalic vein running to the axillary vein
 By lateral pectoral nerve and thoracoacromial artery
o Becomes suspensory ligament of the axilla
Lecture 7 (Vertebral Column)
Vertebral Column (body resists compressive forces)
o Cervical: made up of 7 vertebrae, have transverse foramen for vertebral arteries,
 C1: no actual body, called the atlas, holds skull, has transverse ligament running across the
vertebral canal to separate spinal cord from the dens of C2, superior facets sit upon the lateral
mass of C1
 C2: has dens that allows atlas to turn right and left, dens starts as body of C1
o Thoracic: body looks like a heart, articular facets are horizontal, spinous process longer and narrower
 have costal facets for tubercle on the ribs on the transverse process
 costal demifacets: superior and inferior half facets for ribs to attach the bodies of two vertebrae
 superior attachment for its own rib (T2 superior facet = rib 2, inferior facet 1)
 inferior attachment for the inferior rib
 T1= special case, rib 1 attaches wholly to T1
o Lumbar: large, bulky body because it carries the upper body weight, broad spinous process, no rib
articulation, but the facets are mainly sagittal for flexion/extension
 Mamillary bodies: on the back rim of each superior facet for multifidus to attach to
o Sacrum: 5 fused vertebrae, wing like process of each vertebrae (alae) used for attachment to the ilium, body
of 1st sacral vertebrae has sacral promentary
 Posterior Crests
 Median Crest: on the midline this is the fusion of the spinous processes
 Intermediate Crest: fused articular processes
 Lateral Crest: fused transverse processes
 Sacral Hiatus: notch/opening created by missing laminae
Curvatures of Vertebral Column
o Primary Curve: convex on posterior surface, present at birth (kyphosis)
 Ending with thoracic and sacral/coccygeal
o Secondary Curve: Concave on posterior surface, develop after birth (lordosis)
 Ending with cervical and lumbar
Intervertebral Disc
o Cartilaginous Joint (Symphysis)
 Discs make up 20-30% of the vertebral column height, lose height during the day
 In the cervical region the centers of the discs are smaller and the discs are thicker which gives
increased flexibility
 Thoracic discs are thinner and less mobility
 Herniated discs: more likely lateral because no longitudinal ligaments
 When nucleus pulposus comes through the annulus fibrosus
 Ligaments of Vertebral Column
o Anterior Longitudinal Ligament: covers anterior surface of the intervertebral disc and prevents disc
herniations, runs down the vertebral column on the anterior side of the bodies
 Prevent extension
o Posterior Longitudinal Ligament: covers the posterior surface of the intervertebral discs, helps prevent
herniations, runs down the vertebral column on the posterior side of the bodies in the vertebral canal
 Prevent flexion
o Supraspinous Ligaments: run along tops of the spinous processes
o Interspinous ligaments: run in between the spines of the spinous processes
 Limits flexion
o Ligamentum Flavum: runs on the posterior side of the vertebral canal between adjacent laminae
 Limits flexion
Lecture 8 – June 8th
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Spinal Cord
o Spinal cord is 0.5 meters in length and 1-1.5 centimeters in diameter
o Coming off the spinal cord are 31 pairs of spinal nerves
 These nerves leave the intervertebral foramina
 The smaller rami goes to the back and is the dorsal rami, the second branch is the ventral primary
rami and is larger and carries information to the muscles
o Dorsal Primary Rami: convey info between the deep intrinsic back muscles and skin receptors on either side
of the midline
o Ventral Primary Rami: larger in diameter, convey motor info to remainder of skeletal muscles, as well as
sensory info between the skin on the rest of surfaces,
o Enlargements: C3-T1: Cervical Plexus
 L1-S2: Lumbar Plexus
 C5-T1: Brachial Plexus
o Conus Medullaris: ends at about L2, the end of the firm spinal cord
Gray Matter: consists of cell bodies, dendrites, and unmyelinated axons
o Dorsal gray horn: receive incoming sensory fibers
o Ventral gray horn: site of cell bodies of alpha motor neurons to skeletal muscles
o Lateral gray horn: located on the thoracic and upper lumbar site of cell bodies of ANS (sympathetic) nervous
system
White Matter: consists of myelinated axons
o Dorsal Column: ascending up to the brain
o Lateral Column: descending to peripherary
Commisures
o White: anterior and posterior
o Gray: anterior and posterior
Central Canal: embryonic space that does not go completely away, sits right in the middle of the white matter
Dorsal Rootlets/roots: multiple branches that cover whole surface of the spinal cord and turn into rami
o Carry afferent fibers: cell bodies of fibers in dorsal root ganglian
Ventral Rootlets: cover the surface of the spinal cord and turn into the ventral rami
Dorsal Root Ganglion: a group of cell bodies in the dorsal root
Spinal Nerve: carry a mixture of fibers, at least motor and sensory, some supply viscera (ANS fibers) and somatic (to
and from outer body wall and skeletal muscle)
o 8 Cervical Spinal nerves
 C1 nerve exits above C1 vertebrae, C8 exits below C7 vertebrae
o 12 Thoracic Spinal nerves
 Nerves exit below the vertebrae
5 Lumbar Spinal Nerves
5 Sacral Spinal Nerves
1 Coccygeal Spinal Nerve
Proprioceptive fibers: sensory fibers carrying information from joints and muscles (balancing), and about the
rate of muscle fibers firing to the brain
o Primary Rami: to epaxial muscles (deep back muscles) and skin on either side of the dorsum of the back
o Ventral Rami: to hypaxial muscles (rest of skeletal muscles including limbs)
Autonomic Rami: contain white ramus communicant
o White ramus communican: carries pre-ganglionic sympathetic fibers from lateral horns of central gray of
spinal cord (thoracolumbar regions)
o Gray ramus communican: carries post-ganglionic sympathetic fibers from paravertebral ganglia back to the
spinal nerve
 Effect hairs and sweat glands through this channel of communication
Meninges
o Epidural Space: outermost space that is mainly fatty tissue
o Dura mater: means tough mother, fibrous outermost layer over spinal cord and brain
o Subdural Space: space in between the dura mater and the arachnoid space
o Arachnoid mater: fibrous spider web like covering, lots of pockets, network of fibers
o Arachnoid space: this space is filled with cerebral spinal fluid
o Pia Mater: inner most layer that is connected with the spinal cord, if you remover this layer you will remove
some nervous tissue from the spinal cord
Other Terms
o Denticulate Ligaments: arises from the pia mater, attaches the spinal cord to the dura mater and vertebral
canal, helps to stabilize
o Filum Terminali: tough threadlike structure that keeps spinal cord in place, continuance of membrane
o Cauda Equina: a bundle of spinal nerves that have stretched out, come off the bottom of the spinal cord but
in order to reach legs stretched out
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Lecture 9 --- Deep Back Muscles --- June 8th
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Fascial Compartments of the Back
o Thoracolumbar fascia: tough, thick triangular shaped sheet of connective tissue that covers the lower back,
partial site of origin for lattisimus dorsi and abdominal oblique muscles
o Thoracolumbar Fascia Laminae: posterior lamina attaches to the spinous processes of the lumbar
vertebrae, middle lamina attaches to the transverse processes and anterior lamina (deepest layer) attaches
to anterior surface of transverse processes
Muscular Arrangement
o Extrinsic: attach to the back but also the extremities (lat attaches to arm, trap to scapula)
o Intrinsic: attach only to the back
Superficial Extrinsic Back Muscles
o Trapezius, Latissimus dorsi, levator scapulae, rhomboid major and minor
Intermediate Extrinsic Back Muscles
o Serratus Posterior Inferior, Serratus Posterior Superior
Intrinsic Back Muscles
o Three Groups (Superficial, Intermediate, Deep)
o Spinotransversalis System
 Splenius Group (Capitis and Cervisis)
o Intermediate Group (Sacrospinalis System)
 Erector Spinae Group (Iliocostalis, Longissimus, and Spinalis)
o Transversospinalis System
 Semispinalis, multifidus, rotatores
o Internal Segmental Muscles
 Interspinales and intertransversarii
Muscles (intermediate extrinsic back muscles)
o Serratus Posterior Superior
 Origin: ligamentum nuchae, spinous process of C7-T2
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 Insertion: ribs 2-5
 Action: elevate ribs during breathing
 Innervation: ventral ramus of intercostals T1-3
o Serratus Posterior Inferior
 Origin: spinous processes of T11-L2
 Insertion: ribs 10-12
 Action: pull lower ribs inferiorly and counteracts diaphragm
 Innervation: ventral ramus of intercostals T9-T12
Intrinsic Muscles (Superficial Layer)
o Splenius Capitis
 Origin: ligamentum nuchae, spinous processes C7- T3
 Insertion: superior nuchal line and mastoid process
 Action: rotate head to the same side, extend head
 Innervation: Dorsal rami of middle cervical spinal nerves
o Splenius Cervisis
 Origin: T3-T6
 Insertion: cervical transverse processes of C1-3 with levator scapulae
 Action: rotate head to the same side, extend neck
 Innervation: Dorsal rami of lower cervical spinal nerves
Intrinsic Muscles (Intermediate Layer)
o Erector Spinae Group
o Iliocostalis
 Origin: iliac crest and sacrum
 Insertion: ribs 1-12
 Action: extend the spine, lateral flexion
 Innervation: dorsal rami of spinal nerves
o Longissimus
 Origin: sacrum and transverse processes
 Insertion: most of the ribs
 Action: extends the spine
 Innervation: dorsal root of spinal nerves
o Spinalis
 Origin: spinous processes of T11-12
 Insertion: spinous processes of thoracic and lower cervical vertebrae
 Action: extension and bilateral flexion
 Innervation: dorsal rami of spinal nerves
Intrinsic Muscles (Deep Layer and Transversospinal Group)
o Semispinalis Cervisis
 Origin: transverse processes of T1-T4
 Insertion: C3-5
 Action: extension of vertebral column
 Innervation: dorsal rami of cervical and thoracic nerves
o Semispinalis Capitis
 Origin: Transverse processes of T1-T6 and C4-7
 Insertion: between superior and inferior nuchal line
 Action: extends the head
 Innervation: dorsal rami of cervical and thoracic spinal nerves
o Multifidus
 Origin: sacrum and transverse processes all the way up to C4 (on the transverse processes right by
the superior articular facet is a mammillary process that multifidus attaches to)
 Insertion: spans 3 segments and attaches to spinous process
 Actions: rotates vertebral column and extension
 Innervation: dorsal rami of spinal nerves
o Rotatores
 Origin: transverse processes of lumbar through lower cervical vertebrae and sacrum
 Insertion: spinous processes (long spans 2 vertebrae and short spans one
 Action: contralateral rotation and extension
 Innervation: dorsal rami of spinal nerves
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Segmental group
o Interspinales
 Origin: spinous processes of most vertebrae (except T)
 Insertion: spinous processes
 Action: Extend and rotate vertebral column
 Innervation: dorsal rami of cervical nerves
o Intertransversarii
 Origin: transverse processes of most vertebrae except thoracic
 Insertion: transverse processes of adjacent vertebrae
 Action: unilateral flexor, stabilize vertebral column
 Innervation: dorsal and ventral rami of spinal nerves
o Levator costarum
 Origin: transverse process of C7-T11
 Insertion: ribs 1-12
 Action: elevation of ribs, assist in respiration, assist with lateral flexion
 Innervation: dorsal rami of C8-T11 spinal nerves
Lecture 10 --- Thoracic Osteology
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Superior Outlet: Boundaries include first thoracic vertebrae, medial borders of the first ribs and cartilages and the
manubrium
Inferior Outlet: boundaries include twelfth thoracic vertebrae, the twelfth rib, costal margins and the xiphisternal
joint (not xiphoid process)
Cutaneous Innervation: clavicular and scapular regions (C3-4)
o Region of xiphoid process T6
o Anterior thorax T1-T6
o Upper Extremity C5-T1
o Lower Thorax and anterior abdomen: T7-T12
Structure of the Thoracic cage
o Twelve thoracic vertebrae, twelve pairs of ribs and costal cartilage, sternum and intercostal muscles
Deltopectoral Triangle
o Cephalic V, Deltoid branch of thoracoacromial A., and lymph nodes
Bones of the Thoracic Cage
o Manubrium: articulates with the superior aspect of the body of the sternum at the sternal angle and the
clavicle and the first rib
o Sternum: made of four fused sternaebrae, the sternal body is fused into a single bone from the 6 th rib to
the second rib as a young adult
 The manubriosternal joint is a symphysis and may be ossified in 10% of adults
Ribs
o A rib bone and its cartilage constitute a costa
o Ribs 1-7 are vertebrosternal
o Ribs 8-10 are vertebrochondral
o Ribs 11-12 are floating ribs
o Parts of the rib: head, neck, tubercle, shaft, sternal extremity, crest, angle, costal groove
First Rib
o Flattened (more shelflike) from above downward
o Scalene tubercle (scalene attaches to this point)
 Sub-clavian vein crosses the rib anterior to the tubercle
 Sub-clavian artery crosses the rib posterior ro the tubercle
Thoracic Vertebrae
o Heart shaped centrum (body)
o Centrum notched on left side for descending aorta
o Intervertebral discs make up ¼ of total length of thoracic vertebral region, the vertebral bodies make up
the remaining 3/4
o Superior and inferior costal demifacets (T2-T9)
o Vertebra Prominens (C7)
 First spinous process to be palpated
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Joints
o
T1 spinous process most prominent
Synovial Joints in Ribs
 The head of a typical rib articulates with its own superior costal facet and the inferior costal
demifacet of the vertebrae above it
 The rib also articulates with the vertebral body!
 the tubercle articulates the costal facet on the transverse process of the same number vertebrae
o Costochondral Joints
 Found between the lateral end of the costal cartilage and the sternal end of the rib
 These joints are synchondroses
Intercostal Muscles
o External Intercostals
 Fibers directed downward and inward, muscle runs from the tubercle to the costochondral
junction, DOES NOT EXTEND ALL THE WAY TO STERNUM
o Internal Intercostals
 Fibers are directed downward and backwards
o Innermost Intercostals
Mechanics of Respirations
o During quiet breathing the diaphragm is the most important muscle
o Force inhalation or exhalation
 The dimension of the rib cage increase when upper six ribs elevate, causes sternum to move
forward, neck muscles of upper extremities may serve as accessory muscles in deep inspiration
 Pump handle
 Lateral dimension of thorax can be increased when lower ribs are elevated (bucket handle)
 The intercostal muscles of the rib cage act to stabilize the soft tissue walls between the ribs
and maintain the intercostal spacing during inspiration and expiration, without these muscles
the chest wall would tend to depress
BLOCK 2
(Lectures 14-18)
Axilla – pyramid shaped structure with apex toward next
Boundaries of Base of Axilla (square)
 Anterior - Pectoralis major muscle
 Posterior - Latissimus dorsi muscle
 Medial - Thoracic wall
 Lateral - Humerus
Boundaries of Apex of Axilla: (triangle)
 Anterior - clavicle
 Posterior - superior border of scapula
 Medial - first rib
Content
 Vessels
o Axillary artery and vein
o Cephalic & Basilic veins
o Axillary lymph nodes
 Nerves
o Cords of the brachial plexus
o Long thoracic nerve
o Proximal ends of terminal nn. of brachial plexus
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Ex. Ulnar, radial
Lateral Cervical Triangle
Previously called the posterior triangle as seen in the picture
Side of neck, start of brachial plexus
Boundaries
 Anterior – posterior border of SCM mm
 Posterior – anterior border of trapezius
 Inferior – clavicle
 Roof – skin and superficial layer of deep cervical fascia (contains platysma mm, superficial vv, cutaneous nn
 Floor – muscle and prevertebral fascia (covers splenius capitis, levator scapulae, scalenus posterior, scalenus
medius, scalenus anterior and omohyoid)
Content
 Nerves
o Lesser Occipital (C2)
o Supraclavicular (C3,4)
o Spinal Accessory (CN XI) to traps and SCM mm
 Vessels
o Occipital Artery
o Transverse Cervical Artery
o Subclavian artery and vein (crosses first rib)
o External jugular vein
Muscles of the Floor of the Lateral Cervical Triangle
Muscle
Origin
Insertion
Action
Innervation
Splenius Capitus
Inferior half
ligamentum
nuchae, C7 and
T1-3 (T4) spines
Superior nuchal
line and mastoid
processes
Rotate head and
neck to same side;
bilaterally extend
the head
Dorsal rami of
middle cervical
spinal nerves
Splenius cervicis
T3-T6 spine
C1-C3 (C4)
transverse
processes with
levator scapulae
Rotate head and
neck to same side;
extend neck
Dorsal rami of
lower cervical
spinal nerves
Levator Scapulae
Posterior tubercles
of transverse
processes of C1-C4
vertebrae
Medial border of
scapula superior
to root of scapular
spine
Elevates scapula
and tilts glenoid
cavity inferiorly by
rotating scapula
Dorsal scapular
nerve (C4,C5)
Scalenus Posterior
Posterior tubercles External border of
of transverse
rib 2
processes of C5-C7
Flexes neck
laterally; elevates
rib 2 during forced
inspiration
Ventral rami of
cervical spinal
nerves (C7,C8)
Scalenus medius
Posterior tubercle
Superior surface of Flexes neck
Ventral rami of
of transverse
processes of C5-C7
rib 1, posterior to
groove for
subclavian artery
laterally; elevates
rib 1 during forced
inspiration
cervical spinal
nerves
Scalenus anterior
Transverse
processes of C3-C6
Superior surface of
rib 1, anterior to
groove for
subclavian a
Flexes neck
laterally; elevates
rib 1 during forced
inspiration
Ventral rami of
cervical spinal nn
(C4-6)
Omohyoid
Superior border of Inferior order of
scapular near
hyoid bone
suprascapular
(superior belly)
notch; passes
through fascial slig
near proximal end
of clavicle, forming
an inferior and
superior belly
Depresses,
retracts, and
steadies (fixes)
hyoid bone
C1-C3 via a branch
of the ansa
cervicalis
Brachial Plexus
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Originates from C5-T1
Each spinal cord level has afferent (sensory) and efferent (motor) fibers
Dorsal rami run to epaxial muscles
Ventral rami run to hypaxial muscles
Ventral Rami  Trunks  Divisions  Cords  Terminal nerves
Ventral Rami (C5-T1)
 Exit between scalenus anterior and scalenus medius
 Direct branches off the ventral Rami
o Dorsal scapular n (C5) to Rhomboids
o Long thoracic n (C5-7) to serratus anterior
Trunks
 Located superior to the clavicle above and behind the subclavian artery
 Superior Trunk
o from C5 & C6 ventral rami
o Direct branches off superior trunk
 Suprascapular n (C5, C6) to supraspinatus and infraspinatus
 Nerve to subclavius
 Middle Trunk
o from C7 ventral rami
o no direct branches
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Inferior Trunk
o from C8 & T1 ventral rami
o no direct branches
Divisions
 occur between the clavicle and the first rib
 Anterior
o Go to the anterior compartment of the UE (flexor mm)
o Form lateral and medial cords
 Lateral Cord: anterior branches from the superior and middle trunks
 Medial Cord: anterior branches from the inferior trunk
 Posterior
o Go to the posterior compartment of the UE (extensor mm)
o Form the posterior cord
 Receives posterior branches from all three trunks
Cords
 Accompany axillary artery (cords named in reference to artery)
 Lateral Cord (C5,C6,C7 ant fibers)
o Direct Branches:
 Lateral pectoral n (C5-C7) to clavicular head of pec major m
o Terminal Nerve:
 Musculocutaneous n (C5-C7)
 Lateral Root of Median N (C5-C7)
 Medial Cord (C8,T1 ant fibers)
o Direct Branches:
 Medial pectoral n (C8-T1) to sternal head of pec major m. and pec minor m.
 Medial cutaneous n to arm (brachium)
 Medial cutaneous n to forearm (antebrachium)
o Terminal Nerves:
 Ulnar n (C8-T1)
 Medial Root of Median N (C8-T1)
 Posterior Cord (C5-T1 post fibers)
o Direct Branches
 Upper subscapular n (C5-C6) to subscapularis m
 Thoracodorsal n (C6-C7) to latissimus dorsi m
 Lower subscapular n (C5-C6) to subscapularis and teres major m
o Terminal Branches
 Axillary n (C5-C6) to deltoid and teres minor m; skin over deltoid m
 Radial N (C5-T1) to posterior compartment of arm and forearm, brachioradialis m
Trunks
Ventral Rami
Divisions
Cords
Terminal Nerves
Bones of the UE
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Sternum
o Manubrium (sternal notch, clavicular and costal facets, sternal angle)
o Body
o Xyphoid
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Clavicle
o Convex anterior and concave posterior
o Muscle attachments: deltoid, pec major, trap, SCM, subclavius
Scapula
o Cross ribs 2-7 in anatomical position
o Posterior surface: scapular spine, supraspinous fossa, infraspinous fossa, spinoglenoid notch, medial
border, superior angle, inferior angle
o Anterior surface: subscapular fossa, scapular notch
 Suprascapular lig passes over scapular notch
 Suprascapular a passes over lig and suprascapular n passes through foramen
o Coracoid Process
 Muscle attachments: biceps brachii (short head), coracobrachialis, pec minor
o Acromium Process
o Glenoid process: articulates with humerus
 Supraglenoid tubercle: biceps brachii (long head) tendon attachment
 Infraglenoid tubercle: triceps (long head) attachment
Humerus
o anatomical neck, surgical neck, head, medial supracondylar ridge, lateral supracondylar ridge, medial
epicondyle, lateral epicondyle, deltoid tuberosity
o Anterior surface:
 Greater tubercle: attachment for supraspinatus, infraspinatus, teres minor mm, also pec major
 Lesser tubercle: attachment for subscapularis, teres major
 Intertubercular groove: latissimus dorsi mm attaches (floor)
 Radial fossa: where radial head hits humerus when flex
 Coronoid fossa: ulna moves into this during flexion
 Capitulum (part of lateral condyle): articulates with radius
 Trochlea (part of medial condyle): articulates with ulna
o Posterior surface:
 Radial groove: for radial n and deep brachial artery
 Olecranon fossa: receives olecranon from ulna during extension
Radius
o Head: articulates with capitulum of humerus
o Neck, styloid process (distal, lateral end), articular surface for scaphoid bone and articular surface for
lunate bone, ulnar notch (distal, medial end), interosseous margin
o Bicipital tuberosity – bicep brachii inserts
o Dorsal tubercle: extensor pollicis longus runs medial to this and extensor carpi radialis longus and brevis
run lateral to it
o Groove for extensor digitorum and indicis mm
Ulna
o Interosseous margin, head (distal), styloid (distal medial), radial notch (proximal), coronoid process,
supinator fossa, supinator crest
o Trochlear notch – articulates with trochlea of humerus
o Olecranon process – triceps insertion
Carpals (Wrist)
o Proximal Row (radial to ulnar)
 Scaphoid, lunate, triquetral, pisiform
 Scaphoid and lunate articulate with radius
o Distal Row (radial to ulnar)
 Trapezium, trapezoid, capitate, hamate
Metacarpals (5)
o Carpometacarpal joint (CMC)
Phalanges (14)
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o
Metacarpophalangeal joints (MCP)
Proximal, Middle, Distal for digits 2-5
 Proximal interphalangeal joint (PIP)
 Distal interphalangeal joint (DIP)
Shoulder Complex
Extrinsic Shoulder Muscles
 Pec major and minor
 Serratus anterior
 Trapezius
 Latissimus dorsi
 Levator scapulae
 Rhomboid major and minor
Sensory Supply to shoulder
 Supraclavicular N (C3-4): skin over the clavicle and superior-lateral aspect of pec major
 Cutaneous branches of dorsal rami: skin over either side of the midline of the back
Scapular Movements
 Elevation: levator scap and rhomboids
 Depression: lats
 Abduction: serratus anterior
 Adduction: middle trap
 Upward rotation: serratus anterior, upper and lower trap (force couple)
 Downward rotation: rhomboids, levator scapulae
Shoulder Movements
 Abduction: middle deltoid, biceps brachii (assist)
 Adduction: pec major, lats
Quadrilateral Space
 Superior: inferior glenohumeral capsule
 Inferior: teres major
 Medial: triceps (long head)
 Lateral: surgical neck of humerus
Contents:
 Axillary nerve
 Posterior circumflex humeral artery
Joints
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Sternoclavicular joint (SC)
o Plane synovial joint
o Articulating surfaces: sternal end of clavicle, manubrium, first costal cartilage
o 3 degrees of freedom
 Elevation & Depression
 Occurs around AP axis
 Elevation: 45 degrees
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 Depression: 15 degrees
 Protraction & retraction
 Occurs around vertical axis
 ROM: 15 degrees each
 Rotation
o Fibrocartilage disc in joint
o Ligaments
 Ant/post sternoclavicular lig – restrict ant/post movements
 Costoclavicular lig- between 1st rib and clavicle; checks elevation
 Interclavicular lig
Acromioclavicular joint (AC)
o Plane synovial joint
o Articulating surfaces: clavicle and acromion
o 3 degrees of freedom
 Scapular rotation
 Winging of vertebral border of scapula
 Tipping of inferior angle of scapula
o Ligaments
 Acromioclavicular lig: reinforce joint capsule
 Coracoclavicular lig: trapezoid portion (lateral) and conoid portion (medial)
Glenohumeral joint (GH)
o Ball and Socket joint, synovial
o Articulation: head of humerus and glenoid fossa of scapula
o Glenoid labrum: fibrocartilage rim around glenoid fossa
o Ligaments
 Glenohumeral
 Coracohumeral
 coracoacromial
o Joint capsule – very lax, up to 1 inch of distraction (high change of dislocation)
Scapulothoracic joint
Rotator Cuff
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Supraspinatus
Infraspinatus
Teres minor
Subscapularis
Scapulohumeral Rhythm
 Uninterrupted movement of UE from dependent position to full abduction
 Simultaneous and coordinated movement of muscles
 Full abduction = 180 degrees
o GH Joint – contributes 120 degrees
o SC joint – 40 degrees
o AC joint – 20 degrees
o Scapulothoracic (ST) movement – 60 degrees
o Ratio of GH to ST = 2:1
 Steps for abduction
o Serratus anterior clamps scapula to thoracic wall
o Rotator cuff snubs head of humerus into the glenoid fossa
o 1st supraspinatus, then deltoid will kick in to help
o At 90 degrees, infraspinatus ER to clear the greater tubercle
 Deltoid paralysis: no axillary n and lose 2/3 of abduction
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Serratus anterior paralysis: no long thoracic n and winging of the scapula
Arteries of the arm
Direct Branches from Aorta: L. subclavian, L. common carotid, Brachiocephalic
R subclavian and R common carotid branch from brachiocephalic
Subclavian Branches Vertebral artery: Traverses foramen magnum, unites with vertebral artery to form basilar artery
 Thyrocervical trunk: 3 branches: Suprascapular, transverse cervical (runs with CN IX), inferior thyroid
 Internal thoracic: gives off ant. Intercostals
Subclavian Artery: passes b/t first rib and clavicle  renamed axillary artery
Axillary Artery: begins at inferior border of first rib
Divided into thirds by Pec. Minor: superior, deep, and inferior to muscle.
 First Part Branches: Superior thoracic artery
 Second Part Branches: Thoracoacromial artery: Pectoral, Deltoid, Acromial, Clavicular Branches
: Lateral Thoracic arterty (supplies Pec. muscles)
Third Part Branches: Anterior circumflex humeral
: Subscapular Thoracodorsal and Circumflex scapular branches
Brachial artery: cont. of axillary artery, beginning at inferior border of Teres Minor
Runs medial to median nerve in upper arm, runs lateral to median nerve in lower arm
Branches of Brachial Artery:
Deep Brachial (profunda brachii) - runs in radial groove with radial nerve
Branches: ascending branch to posterior circumflex humeral
: descending branch to radial collateral
Anastomoses with Radial Recurrent
Superior Ulnar Collateral – runs with ulnar nerve
Inferior Ulnar Collateral – passes anterior to medial epicondyle
Radial Artery: gives off radial recurrent to radial collateral from deep brachial
Ulnar Artery: gives off common interosseous, runs with ulnar nerve
: common interosseous give off anterior and posterior interosseous arteries
Veins of the arm
Cephalic Vein – runs lateral antebrachium- receives from median vein- through deltopectoral triangle-pierces
clavipectoral fascia – empties into axillary vien
Basilic Vein – medial side of antebrachium – receives from median cubital vein –joins venae comitantes for form axillary
vein
Axillary Vein – formed by union of basilica and venae comitantes – renamed subclavian vein after passing under clavicle
Subclavian Vein – forms brachiocephalic vein where subclavian and jugular vein meet – brachiocephalic veins come
together to from superior vena cava
Lymphatics
Drainage is from palmar surface to dorsal surface of hand
Laterally: lymph follows cephalic vein to nodes in deltapectoral groove to axillary nodes
Medially: lymph flows to epitrochlear node to axillary nodes
Lymph Nodes:
Brachial – medial to humerus near axillary artery and vein
Pectoral – behind pec minor, drains mammary gland
Subscapular – lower border of scapula, drains back
Central nodes –in axillary fat, receives lymph from all nodes
Apical nodes – nodes behind clavicle
BRACHIUM COMPARTMENTS
Fascial Septa – connective tissue that divides the arm into anterior and posterior compartments
Medial intermuscular septum –separates anterior arm from medial side of tricep complex
Lateral intermuscular septum – separates anterior arm from lateral side of tricep complex (thicker than medial fascia)
Anterior Compartment:
Components: Biceps brachii, Coracobrachialis, Brachialis
Function: forearm flexors, bicep does some supination
Innervation: Musculocutaneous N. (off of lateral cord), C5-6
Structures passing through: Median and Ulnar nerve
Vascular Supply: Brachial artery, Basilic Vein, Venae Comitantes
Posterior Compartment:
Components: Triceps brachii, Anconeus
Function: forearm extensors, some shoulder extension(long head tricep), synergist in forearm supination
Innervation: Radial Nerve, C7
Vascular Supply: Deep Brachial Artery
Nerves and Vessels of Brachium
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Median Nerve:
o Supplies flexor mm’s on the radial side of forearm
o Travels with brachial artery
o Crosses cubital fossa superficially, deep to bicipital aponeurosis
Ulnar Nerve
o Supplies flexor mm’s on the ulnar side of the forearm
o Starts in ant. brachial compartment
o Pierces medial intermuscular septum
o Passes around medical epicondyle
o Passes into forearm b/t two heads of flexor carpi ulnaris mm.
Radial Nerve
o Supplies extensor mm’s in posterior compartment of brachium
o Supplies extensor mm’s of the wrist and hand
o Supplies Brachioradialis mm.***
o Divides into superficial and deep branches near lateral epicondyle of humerus
o
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Branches in the axilla and upper 1/3
 Muscular branch to long head tricep
 Muscular branch to medical head tricep
 Posterior brachial cutaneous nerve
o Branches in radial groove in middle 1/3
 Branch to lateral and medial tricep and anconeus
 Lower Lateral brachial cutaneous nerve
 Posterior cutaneous nerve
o Branches in distal 1/3
 Branch to brachioradialis
 Branch to extensor carpi radialis longu
 Articular branches to elbow joint (joint capsule)
Musculocutaneous Nerve
o Supplies mm’s of anterior brachial compartment
o Pierces coracobrachialis mm
o Pierces fascia later to bicep tendon
 Continues as lateral cutaneous nerve of forearm
 Supplies skin on lateral forearm as far as wrist
Medial Brachial Cutaneous Nerve
o Direct branch from medial cord
Medial Antebrachial Cutaneous Nerve
o Direct branch from medial cord
Cephalic Vein
o Lateral continuation of dorsal venous arch
o Ascends along lateral aspect of arm and forearm
o Passes through deltopectoral triangle
o Empties into axillary vein
Basilic Vein
o Medial continuation of dorsal venous arch
o Ascends along medial aspect of arm and forearm
o Joins venae comitantes to form axillary vein near inferior border of teres major
Median Cubital Vein
o Connects cephalic and basilic vein
o Receives blood from median antebrachial vein
o Drains blood from palmar hand
o Site for Vena puncture
Venae Comitantes
o Veins in parallel
o Countercurrent heat exchange
Brachial Artery
o Continuation of Axillary artery
o Begins at inferior border of teres major
o Main branch is: Deep Brachial Artery
o Other branches
 Superior ulnar collateral  to posterior ulnar recurrent
 Inferior ulnar collateral  to anterior ulnar recurrent
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Relationships to Remember:
o Radial nerve to deep brachial artery in radial (spiral groove).
o Brachial artery to median nerve.
o Brachial artery to bicipital aponeurosis (deep to).
o Median cubital vein to bicipital aponeurosis (superficial to)
o Ulnar nerve to medial epicondyle.
o Musculocutaneous nerve to coracobrachialis muscle.
o Musculocutaneous nerve to biceps and brachialis muscles.
o Lateral cutaneous nerve of the forearm to the bicipital tendon
Cubital Fossa Boundaries and Contents
o Boundaries
 Lateral – brachioradialis mm
 Medial – pronator teres mm
 Superior Base – line b/t 2 humeral epicondyles
 Floor – Supinator and brachialis mm
o Contents
 Lateral to Medial
 Biceps Tendon
 Brachial Artery
 Median Nerve
Elbow Complex
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Joint Type and Function
o Uniaxial Hinge Joint
o Elbow flextion/extention
o Forearm supination/pronation
Articulating Surfaces
o Humeroulnar
 Trochlear notch to trochlea
 Flexion/extention (hinge joint)
o Humeroradial
 Fovea of head of radius to capitulum
 Flexion/extension
 Pronation/supination
o Radioulnar
 Superior joint
 Radial notch of ulna and annular ligament
 Inferior joint
 Ulnar notch of radius, articular disc, head of ulna
 Intermediate
 Interosseous membrane
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Syndesmosis
Ligaments
o Medial (ulnar) collateral
 Medical epicondyle to coronoid process and olecranon process
 Slack in ligament results in valgus deformity
o Lateral (radial) collateral
 Lateral epicondyle to annular ligament and olecranon process
 Slack in ligament results in varus deformity
o Annular ligament
 Attached to ulna, forming sling around neck of radius
Carrying Angle
o Formed by
 Longitudinal axis of humerus
 Long axis through trochlea
 Results in lateral deviation of antebrachium
 5 deg in men/ 10-15 deg in women
 Increase = cubitus valgus
 Decrease = cubitus varus
Relationships
o Bicipital aponeurosis to brachial artery and median cubital vein.
o Median nerve to brachial artery
o Ulnar nerve to:
 Medial epicondyle – passes around in sulcus
 Olecranon process - laterla
 Origins of flexor carpi ulnaris – passes b/t the two heads of the mm
o Epicondyles of humerus to collateral arteries of cubital region.
o Ulnar artery to deep (ulnar) head of pronator teres.
o Median nerve to heads of pronator teres. –b/t 2 heads of pronator teres
o Superficial and deep radial nerves to supinator muscle. – passes superficial and deep to supinator mm
Anterior Antebrachium
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Muscles
o Flexors:
 Superficial group (from superior inferior and lateralmedial)
 Brachioradialis
 Pronator teres
 Flexor carpi radialis
 Palmaris longus
 Flexor carpi ulnaris
 Intermediate group
o Flexor digitorum superficialis
 Deep group
o Ulnar head of pronator teres
o Flexor digitorum profundus
o Flexor pollicis longus
o
o
o
Vasculature
 Radial Artery
 Terminal branch of brachial artery
 Lies deep to brachioradialis proximally
 Superficial between bracioradialis and flexor carpi radialis distally
 Ulnar Artery
 Lateral to ulnar nerve in distal forearm
 Branches
o Anterior ulnar recurrent (to inferior ulnar collateral)
o Posterior ulnar recurrent (to superior ulnar collateral)
o Common interosseous
Innervation
 Median Nerve
 Supplies mms in anterior compartment not supplied by ulnar nerve
 Functional neurological level = C7
 Crosses anterior cubital fossa medial to brachial artery
 Passes b/t 2 heads of pronator teres
 Travels between flexor digitorum superficialis and flexor digitorum profundus
 Ulnar Nerve
 Innervates flexor carpi ulnaris and half of flexor digitorum profundus
o Median N. innervates all other flexor mm’s in antebrachium
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o
Pronator quadratus
Runs b/t 2 heads of flexor carpi ulnaris
Relationships
 Ulnar artery to ulnar nerve (run together), flexor carpi ulnaris (artery deep to mm), pisiform (just
medial to), Guyon’s canal (artery and nerve run through).
 Median nerve to flexor digitorum superficialis and transverse carpal ligament.
 Superficial palmar branch of median nerve to transverse carpal ligament
 Radial artery to superficial branch of radial nerve and brachioradialis.
Posterior Antebrachium
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Extensor Retinaculum
o Deep fascia – keeps tendons close, following contours of the bone
o Transversely crosses distal ends of radius and ulna
o Extensor tendons lateral to medial
 Abductor pollicis longus
 Extensor pollicis brevis
 Styloid process
 Extensor carpi radialis longus
 Extensor carpi radialis brevis
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 Dorsal tubercle
 Extensor pollicis longus
 Extensor digitorum
 Extensor indicis
Radial Nerve
o Enters antebrachium b/t brachioradialis and brachialis
o Passes in front of lateral epicondyle and enters cubital fossa
o Divides into superficial and deep branches
 Deep Branch
 Wraps laterally around radius b/t superficial and deep layers of supinator
 Motor to all extensor mm’s of forearm EXCEPT extensor carpi radialis longus and
anconeus
 Superficial Branch
 Cutaneous innervation
 Supplies lateral half of dorsum of hand and dorsum of thumb and index finger
Radial Artery
o Smallest terminal branch of brachial artery
o Runs through anatomical snuffbox
 If scaphoid is broken, radial artery may be compromised
o Radial artery Branches:
 Radial recurrent
 Dorsal carpal artery
 Dorsal metacarpal arteries
o Interosseous Arteries
o From common interosseous artery from ulnar artery
o One on either side of interosseous membrane
Superficial Muscles
o Common origin: lateral epicondyle
o Superior to inferior
 Brachioradialis
 Extensor carpi radialis longus
 Extensor radialis brevis
 Extensor digitorum communis
 Extensor digiti minimi
 Extensor carpi ulnaris
Deep Muscles
o Supinator
o 4 mm’s Emerge b/t extensor carpi radialis and extensor digitorum
 Abductor pollicis longus
 Extensor pollicis brevis
 Extensor pollicis longus
 Extensor indicis
WRIST COMPLEX
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Carpal Bones
o Distal Row: Trapezium, trapezoid, capitate, hamate
o Proximal Row
 Scaphoid
 Floor of anatomical snuffbox
 Most commonly fractured wrist bone
 Articulates with radius
 Lunate: articulates with radius
 Triquetrum: articulates with ulna during extreme ulnar deviation
 Pisiform: forms in the tendon of the flexor carpi ulnaris
Radiocarpal joint
o Condyloid (ellipsoidal) synovial joint
o 2 degrees of freedom (flex/ext, Ulnar/radial deviation)
o Articular surfaces
 Scaphoid (convex)
 Lunate (convex)
 Distal radius (concave fossa)
 Triquetrum (convex) – articulation only with extreme ulnar deviation
o Ligaments (strengthens capsule)
 Lateral collateral
 Medial collateral
 Dorsal radiocarpal
 Palmar radiocarpal
o Arteries
 Articular arteries
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 Arises from dorsal and palmar carpal arches
o Radiocarpal Joint nerves
 Anterior interosseaous branch of median nerve
 Posterior interosseaous branch of radial nerve
 Dorsal and deep branches of the ulnar nerve
o Radiocarpal Joint injuries
 Colle’s fracture – fracture of distal radius
 Scaphoid fracture
Midcarpal Joint
o b/t proximal and distal rows of carpals
o movements
 some flex/ext
 radial deviation
 some rotation
o Ligaments
 Dorsal, palmar, and interosseous ligaments
Palmar structure Sequence (radial to ulnar)
o Radius
o radial artery
o flexor carpi radialis tendon
o
o
o
o
o
o
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median nerve
flexor digitorum superficialis tendons
ulnar artery
ulnar nerve
flexor carpi ulnaris tendon
ulna
HAND
Carpometacarpal Joints
o Plane synovial joints
 Motions
 None for digits 2-3
 Limited for 4
 More mobile for 5
o Saddle (sellaris) joint
 B/t metacarpus and trapezium
 Movements
 Abd/add
 Flex/ext
 Circumduction
 Opposition
o Condyloid synovial joints
 Movements
 Flex/ext
 Abd/add
 Some circumduction at MCP 5
 Capsular ligaments
 Palmar ligaments
 Collaterals
Interphalangeal Joints
o Synovial hinge joint
 Flex/ext movement only
 Strong collateral ligaments
Dorsal Venous drainage
o Dorsal venous arch drains hand dorsum
o Medially drains basilica, laterally drains cephalic
Lymphatic Drainage
o Medial via lymph vessels accompanying basilica vein  to supratrochlear and axillary nodes
o Lateral via lymph vessels accompanying cephalic vein  to infraclavicular and lateral axillary nodes
Arterial supply Dorsum of hand
o Dorsal arterial arch  from radial and ulnar arteries
o Dorsal metacarpals and digitals
Muscles of Dorsum of Hand
o Long extensor tendons
o Dorsal interosseous mms
 Abductors
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 Middle finger is reference
 Middle finger has 2 mms
 First and fifth digits have none
Superficial palm
o Palmar aponeurosis
o Flexor retinaculum
o Palmaris brevis
Palmar Aponeurosis
o Triangular layer of deep fascia located between two eminences.
o Provides protection for superficial vessels, nerves, and tendons.
o Anchored to skin and flexor retinaculum.
o Splits into four slips that blend with fibrous flexor sheaths of four medial digits (II – V).
Flexor Retinaculum
o = Transverse carpal ligament.
o Laterally attaches to tubercles of scaphoid and trapezium.
o Medially attaches to hook of hamate and pisiform.
Palmaris Brevis Muscle
o O: Flexor retinaculum and palmar aponeurosis.
o I: Skin on medial side of palm.
o A: Tenses skin on palm.
Carpal Tunnel Contents
o Long flexor tendons of:
 Flexor digitorum superficialis
 Flexor digitorum profundus
 Flexor pollicis longus
o Median Nerve
o Note: ulnar nerve and artery pass through Guyon’s canal.
Intrinsic MMs of the Thumb
o Thenar eminence:
 Adductor pollicis:
 Has transverse and oblique head
 Innervation: Deep branch of ulnar nerve (C8, T1).
 Abductor pollicis brevis
 Flexor pollicis brevis
 Opponens pollicis
 Innervation: Recurrent branch of median nerve (C8, T1).
o Hypothenar Eminence:
 Intrinsic muscles for digit V.
 Abductor digiti minimi
 Flexor digiti minimi brevis
 Opponens digiti minimi
 Innervation: Ulnar nerve
Long Digital Flexors
o Flexor digitorum superficialis
 Flexes PIP (and MCP and wrist).
 Each tendon passes through fibrous flexor sheath.
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 Each tendon bifurcates opposite proximal phalanx.
 Each tendon inserts on middle phalanx
o Flexor digitorum Profundus
 Flexes DIP (and PIP and MCP).
 More active than superficialis.
 Each tendon inserts on distal phalanx
Dorsal Interossei
o Four bipennate muscles.
o Each arises via two heads from adjacent sides of two metacapals.
o Insertion:
 Onto extensor expansions and:
 Radial sides of proximal phalanges 2 and 3;
 Ulnar sides of proximal phalanges 3 and 4.
 Note: digit has two dorsal interossei.
o Abducts MP joints of digits 2-4:
o Reference is line through middle finger.
Palmar Interossei
o Four unipennate muscles:
 First is sometimes considered part of flexor pollicis brevis.
 Supply each digit except third:
 Reference is middle finger.
o Innervation for all interossei (incl. dorsal): Ulnar nerve
Lumbricals
o Four small, narrow, elongated muscles.
o Each arises from the radial side of a flexor digitorum profundus tendon.
o Innervation:
 Two on radial side: Median nerve
 Two on ulnar side: Ulnar nerve
o Flex MCP joints and extend IP joints.
Arterial Supply to hand
o Superficial palmar arch : continuation of ulnar artery
o Deep palmar arch: continuation of radial artery
Radial Artery
o Distally lies against the radius lateral to the tendon of flexor carpi radialis (radial pulse felt here)
o Wraps around the dorsum of first metacarpus to give off deep palmar arch
Anatomical Snuffbox
o Lateral border
 Tendons of abductor pollicis longus and extensor pollicis brevis
o Medial border
 Tendon of extensor pollicis longus
Ulnar Nerve
o Superficial Branch
 Muscular branch to palmaris brevis
 Cutaneous branch to palmar aspect of the ulnar side of the little finger and adjacent sides of the
little and ring fingers
o Deep Branch
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 Supplies hypothenar muscles, interossei, two ulnar side lumbricals and adductor pollicis
Median Nerve
o Enters palm deep to flexor retinaculum.
o Divides into lateral and medial branches:
 Lateral branch:
 To thenar muscles and first lumbrical.
 Cutaneous to anterior surface of thumb and radial side of index finger
 Medial branch
 To second lumbrical.
 Cutaneous to adjacent sides of digits 2-4, including nail-bed and finger tips
Thenar Space
o Located b/t palmar side of the adductor pollicis muscle and the long flexor tendons to the index finger
and thumb
Midpalmar Space
o Located b/t metacarpals 4-5 and the long flexor tendons to digits 4-5
Clinical Notes
o Mallet finger: Avulsion by long flexor tendon, results in hyperflexion of DIP.
o Dupuytren’s contracture: Progressive fibrosis of palmar aponeurosis, results in marked flexion of fingers
at MP joints.
o Colle’s fracture: Fracture of scaphoid
o Median nerve injury: Loss of thumb opposition, atrophy of thenar muscles, “Ape hand”.
o Ulnar nerve injury:
 Paralysis and atrophy of interossei Guttering (between metacarpals on the back of the hand)
 Loss of thumb adduction
 Clawhand (4-5th fingers markedly flexed)
Extensor Mechanism
o Components
 Hood – tendinous on the back MC joint of 4 fingers
 Lateral bands
 To bases of distal phalanges
 Central bands
 To base of middle phalanx
 Function
 Flexion at MCP joint
 Extension at PIP, DIP joints
o Functional notes
 Extension of the PIP is always accompanied by the simultaneous extension of the DIP
 When the PIP is flexed, the DIP may be extended of flexed
If lateral bands detach, the bands will flex the PIP and hyperextend the DIP
Block III
Bones of the Skull (p. 142 in supplemental text)
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Bones of the Anterior Skull
 Frontal, Maxillary, Zygomatic, Nasal, Sphenoid, Ethmoid, Lacrimal, Vomer
Frontal bone (unpaired)
 Paired in the fetus, fused in adult (Metopic suture)
 Contains supraorbital foramina
Maxillary bones
 Contains alveolar processes and infraorbital foramen
Zygomatic bones
 Aka Malar bones
Spenoid (unpaired) – 6 different parts of the bone
1. Body
 Contains hypopyseal fossa (sella turcica) for pituitary gland
2. Greater Wings
 Contains foramen rotundum, foramen ovale, and foramen spinosum
3. Lesser Wings
 Optic Canal
 Anterior and Posterior Clinoid process
 For attachment of membrane that covers pituitary gland (diaphragm sellae)
4. Pterygoid process
 Site of muscles attachment for jaw movers
5. Pterygoid Fossa
6. Hamuli
Ethmoid – Contains 5 structures
1. Crista Galli
2. Perpendicular (vertical plate)
3. Cribriform plate (between crista galli and perpendicular plate)
4. Labyrinth
a. Contains superior and middle nasal conchae
5. Ethmoid Air Cells
Lacrimal
 Contains canal for where tears can escape
Vomer
 Divides nasal cavity into 2 halves.
Bones of the Lateral Skull
 Parietal (paired), Occipital (unpaired), Temporal
Occipital Bone (Unipaired) – 5 Structures
1. Occipital Condyles
a. One either side of foramen magnum
b. Articulate with C1
2. Foramen Magnum
a. Entrance of the spinal cord
3. Supreme, Superior, and Inferior Nuchal lines
a. For muscle attachment
4. External Occipital Protuberance
a. Where the three nuchal lines meet
5. Pharyngeal protuberance
a. Attachment site for pharynx
3 parts of the temporal bones
 Squamous part
 flat
 Petromastoid part
 Contains mastoid process
Posterior Fontanelle
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Tympanic part
 Contains External Auditory Meatus
Sutures
 Sagittal
 Lambdoidal
 Coronal
 Metopic
Fontanelles
 Anterior (aka “soft spot”)
 Posterior
 Posterolateral (Mastoid fontanelle)
 Anterolateral (sphenoidal fontanelle)
Mandible (3 parts)
 Ramus – for muscle attachment of jaw closers
 Angle
 Body
 Contains mental foramen for mental artery and nerve
Cranial Cavity (p. 149 in supplemental text)
Anterior Cranial Fossa
 Formed by the frontal bone
 Features:
o Crista galli
o Cribriform plate & Olfactory foramina
o Anterior clinoid process
 Contains frontal lobes of the cerebrum
Middle Cranial Fossa
 Formed by body and greater wings of the spenoid bones
 Features
o Dorsum sellae
o Posterior clinoid process
o Chiasmatic sulcus (for optic chiasm)
o Optic canal (for optic nerve)
o Superior orbital fissures
o Foramen rotundum
o Foramen ovale
o Foramen spinosum
o Foramen lacernum
 Contains temporal lobes of the cerebrum
Posterior Cranial Fossa
 Formed by occipital bone
 Features
o Clivus (brainstem rests here)
o Foramen magnum
o Jugular foramen
o Hypoglossal canal
o Condylar canal
o Mastoid canal
 Tentorium Cerebelli
o
o
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Roof over top of the posterior cranial fossa.
Tentoral incisures
 Opening that brainstem runs through to get to middle cranial fossa
Contains cerebellum, pons, and medulla
Suboccipital Triangle (p. 151 in supplemental text)
Structures that hold your head on the rest of your body
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Vertebral Column Ligaments (Ligaments that hold your head on)
o Anterior longitudinal ligament
o Posterior longitudinal ligament
o Ligamentum Flavum
o Ligmentum Nuchae (supraspinous ligament + interspinous ligament)
3 synovial joints of the suboccipital triangle
o Between dens and anterior arch of atlas
o Between lateral masses of atlas and axis (2)
Ligaments that extend to the skull
o Apical ligaments
o Alar ligaments
o Cruciate ligaments
o Tectorial liagments
Muscles of the Suboccipital triangle (pictured on p. 153 of supplemental text)
o Obliquus capitis superior
 Weak extensor of the neck
o Obliquus capitis inferior
 Strong rotator of the atlas
o Rectus capitis posterior major
 Extension of vertebral column
o Rectus capitis posterior minor
 Extension of vertebral column
Floor of suboccipital triangle
o Posterior atlanto-occipital membrane
Roof of suboccipital triangle
o Semispinalis capitis muscle
Contents of the suboccipital triangle
o Suboccipital nerve
 Dorsal ramus of C1
 No sensory function and no dorsal root
 Motor to muscles of the suboccipital triangle
o Greater occipital nerve
 Dorsal ramus of C2
 Sensory to back of skull
o Third occipital nerve
 Doral ramus of C3
o Verterbral Artery
Scalp and Meninges (p. 154 in supplemental text)
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Layers of the scalp (from superficial to deep)
o Skin
o Connective Tissue
o Aponeurosis
o Loose Areolar Tissue
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o Pericranium (Like periosteum of the skull)(
Cutaneous Nerve Supply to Scalp
o CN V (Trigeminal – all 3 branches)
 Opthalmic, Maxillary, Mandibular
 Skin on face area
o Great auricular nerve and Lesser occipital nerve
 Side of scalp around ear
o Greater occipital nerve
 Skin on back of scalp
Vascular Supply to Scalp
o Branches of External carotid artery
 Occipital, Posterior auricular, Superficial temporal
o Branches of Internal carotid artery
 Supratrochlear, Supraorbital
Vascular Supply to Meninges
o Arteries
 Meningeal arteries
 Middle meningeal artery
o Veins
 Emissary veins (within dura mater)
 Diploic veins (in spongy bone of cranium)
 Cerebral veins (drain blood from brain)
What is dura mater?
o Tough outer connective tissue layer that forms a sack around the brain and encloses the dural venous
sinuses.
4 Reflections of the dura mater
o Falx cerebri
 Between two cerebral hemispheres
o Tentorium cerebelli
 Between cerebellum and occipital lobes of cerebral hemispheres
o Falx cerebelli
 Between 2 cerebellar hemispheres
o Diaphragm sellae
 Over hypophyseal fossa where pituitary gland sits (anchored by ant. and post. clinoid processes)
Dural Venous Sinuses (6) (Pictured on p. 102 in Netter’s)
o Superior sagittal sinus (unpaired)
o Inferior sagittal sinus (unpaired)
o Straight sinus (unpaired)
o Confluence of sinuses
 common confluence of superior sagittal sinus and straight sinus
o Transverse sinus (paired)
 Right receive blood from superior sagittal sinus
 Left receives blood from straight sinus
o Sigmoid sinus (unpaired)
 Continuation of transverse sinus
 Ends at jugular foramen where it joins with internal jugular vein
Meninges (deepest layer to most superficial layer)
o Pia Mater
o Arachnoid
 Intermediate layer that is attached to pia mater and dura mater
 Subarachnoid space
 Separates arachnoid mater from pia mater
 Contain cerebrospinal fluid


Arachnoid villi
 Projections from subarachnoid space into sinuses for reabsorption of cerebrospinal fluid
Subarachnoid cisterns
 Contains choroid plexuses
o Folds in brain covering that are highly vascularized and responsible for
formation of CSF
Cranial Nerves (p. 156 in supplemental text)







Modality – the type of information a nerve is carrying (7 different types)
o SSS: Special Somatic Sensory
 Sensation of sight, sound and balance
o SVS: Special Visceral Sensory
 Sensation of taste and smell
o SVM: Special Visceral Motor
 Supplies muscles derived from pharyngeal arches (neck region)
o GVS: General Visceral Sensory
 General sensation from viscera (gut tube, bronchial tree, etc)
o GVM: General Visceral Motor
 Parasympathetic motor
o GSS: General Somatic Sensory
 General sensation from skin
o GSM: General Somatic Motor
 Skeletal muscles (other than pharyngeal arch muscles)
“Sensory” can be replaced with “Afferent” and “Motor” can be replaced with “Efferent” in each of the modality
names.
Difference between a nerve and a tract?
o Nerve= bundle of fibers in PNS
o Tract= bundle of fibers in CNS
Doral root = Sensory (afferent)
Ventral root = Motor (efferent)
Where do motor cranial nerves begin?
o Within the brain within motor nuclei
Where are sensory fibers cell bodies located?
o Dorsal root ganglia
Non-parasympathetic Cranial Nerves
 Olfactory, Optic, Oculomotor, Trochlear, Abducens, Vestibulocochlear, Spinal Accessory, Hypoglossal
Cranial Nerve
Modality Function
Sensory
Foramen
Origin
Other information
area/muscles
innervated
Olfactory (CN I)
SVS
Smell
Smell
Cribriform
Plate
Olfactory
receptor
cells
N/A
Optic (CN II)
SSS
Vision
Sight
Optic Canal
Ganglionic
layer of
retina (not
rods and
cones)
50% decussation in
optic chiasma (fibers
from both optic
nerves cross to
opposite side of
brain).
Oculomotor (CN
III)
GSM
Eye
Movement
Levator
Superior
palpebrae
Orbital
superioris and
Fissure
4 of 6 extrinsic
eye muscles:
superior
rectus, inferior
recturs, inferior
oblique, medial
rectus
Oculomot
or nuclear
complex
Also has
parasympathetic
component
Trochlear (CN
IV)
GSM
Eye
Movement
Superior
Oblique Muscle
of Eye
Superior
Orbital
Fissure
Cerebral
Aquaduct
N/A
Abducens (CN
VI)
GSM
Eye
Movement
Lateral Rectus
Muscle of Eye
Superior
Orbital
Fissure
Abducens
Nucleus
Lies on medial side
of lateral rectus
muscle
Vestibulocochlea
r
SSS
Balance
and
Hearing
Auditory and
Vestibular
areas
Internal
Acoustic
Meatus
Vestibular
Componen
t:
Vestibular
ganglion
Broken up into two
components:
vestibular and
cochlear
Auditory
Componen
t: Spiral
ganglion
of
cochlea.
Spinal Accessory
(CN XI)
SVM
Muscle
Movement
Sternocleidoma Jugular
stoid and
Foramen
Trapezius
(both
pharyngeal
arch muscles)
Upper 3-4
segments
of Cspine.
N/A
Hypoglossal (CN
XII)
GSM
Tongue
Movement
Intrinsic and
Extrinsic
tongue
muscles
Hypogloss
al nucleus
N/A
Parasympathetic Cranial Nerves

Oculomotor, Facial, Glossopharyngeal, Vagus
Hypoglossa
l Canal
Cranial Nerve
Modality
Function
Sensory
area/muscles
innervated
Foramen
Origin
Other
information
Oculomotor (CN
III)
GVM
Eye
Movement
Sphincter
Pupillae
(constricts
pupil) & ciliary
muscles
Superior
Orbital
Fissure
Preganglonics
N/A
: Edinger
Westphal
nucleus
Postganglonic
s: Ciliary
ganglion
Trigeminal (CN
V)
SVM
Muscle
movement
(NOT
parasympathetic
)
Muscles of
mastication,
Tensor veli
palatini,
Tensor
tympani,
Mylohyoid,
Anterior belly
of digastric
Opthalmic:
Masticator
nucleus
Three branches:
Opthalmic,
Maxillary,
Mandibular
Same as
above
Trigeminal
ganglion
Same as above
Internal
acoustic
meatus
From superior
salivatory and
lacrimal nuclei
to
submandibula
r ganglia
5 Branches:
Superior
Orbital
Fissure
Maxillary:
Foramen
Rotundum
Mandibular
: Foramen
ovale
Trigeminal (CN
V)
GSS
Sensation
from head
(NOT
parasympathetic
)
Facial (CN VII)
Sensation
from:
Face and ant.
scalp, eyeball,
paranasal
sinuses, nasal
and oral cavity,
ant. 2/3 of
tongue,
external
surface of ear
drum, dura of
ant. and
middle cranial
fossa
GVM
Motor
supply
Lacrimal gland
Submandibular
gland
Mucous glands
of mouth and
Temporal
Zygomatic
Buccal
nose
Mandibular
Cervical
Facial (CN VII)
GSS
Sensation
Sensory to part Internal
of external ear acoustic
meatus
Geniculate
ganglion
Same as above
Facial (CN VII)
SVS
Taste
Carries taste
from ant. 2/3
of tongue and
hard and soft
palate.
Internal
Acoustic
Meatus
Ganiculate
ganglion
Same as above
Glossopharyngea
l (CN IX)
SVM
Muscle
Movement
Muscles of
third
phaeryngeal
arch
Jugular
Foramen
Nucleus
ambiguous
N/A
Glossopharyngea
l (CN IX)
GVS
Sensation
Sensation to
post. 1/3 of
tongue
Jugular
Foramen
Carotid body
and Carotid
Sinus
N/A
Glossopharyngea
l (CN IX)
GVM
Motor
supply
Motor to
parotid gland
Jugular
Foramen
Inferior
salivatory
nucleus to
otic ganglion
N/A
Glossopharyngea
l (CN IX)
GSS
Sensation
Sensation from
post. 1/3 of
tongue,
external ear,
middle ear
cavity.
Jugular
Foramen
Carotid body
and carotid
sinus
N/A
Glossopharyngea
l (CN IX)
SVS
Sensation
Senation from
post. 1/3 of
tongue.
Jugular
Foramen
Carotid body
and carotid
sinus
N/A
Vagus (CN V)
SVM
Motor
supply
Almost all
muscles of
pharynx and
larynx
Jugular
Foramen
Nucleus
ambiguous
N/A
Vagus (CN V)
GVS
Sensation
Sensation from
larynx and
pharynx and
thoracic and
abdominal
Jugular
Foramen
Nucleus
ambiguous
N/A
viscera
Vagus (CN V)
GSS
Sensation
Sensation from
external ear
and pharynx
Jugular
Foramen
Nucleus
ambiguous
N/A
Vagus (CNV V)
GVM
Motor
supply
Preganglionics:
Jugular
Foramen
Dorsal motor
nucleus
Major
parasympathetic
nerve to thoracic
and abdominal
organs.
to myenteric
plexus of wall
of gut tube.
Postganglionics
: to smooth
muscle of
pharynx and
larynx and
smooth muscle
of most of wall
of gut tube.
Ear (p. 168 in supplemental text)
Outer Ear
 Auricle
o Layer of skin over cartilage framework
 External Acoustic Meatus
o From auricle to tympanic membrane
o Lined by skin and ceruminous glands (ear wax glands)
Middle Ear
 Tympanic Membrane
o Covered by skin externally and mucosa internally
 Tympanic Cavity
o Contains two opening
 Round window
 Oval window
 Auditory ossicles
o Contains three bones
 Malleus (attached to tympanic membrane)
 Incus
 Stapes (attacted to oval window)
 Stapedius muscle
o Contracts reflexively in response to loud sounds.
o Inserts onto stapes
o Innervated by CN VII
 Tensor tymapni muscle
o Contracts reflexively in response to loud sounds.
o Inserts onto malleus
o Innvervated by CN V-3 (Mandibular nerve)
 What gives off Tympanic nerve?
o CN IX. GSS to muscosa of tympanic cavity, mastoid air cells and auditory tube.
Inner Ear







Lies within Petrous part of temporal bone.
Consists of two portions
o Bony labyrinth
o Membranous labyrinth
Supplied by labyrinthine artery
Cochlea
o Resembles a snail shell
o Contains the round window
o Supplied by cochlear (auditory) nerve from CN VIII)
Vestibule
o Contains:
 Utricle and Saccule (structures involved in equilibrium).
Semicircular Canals
o Anterior, posterior, and lateral
o Arranged in three planes
o Dilated at one end to form amulla.
 Senses rotational acceleration.
Utricle and Sccule
o Sense linear acceleration and pull of gravity
o Supply by vestibular nerve (CN VIII)
Orbit (p. 169 in supplemental text)
Part of the Orbit
Bones
Related to
Special Features
Roof
Frontal Bone, Lesser
wings of sphenoid
bone
Frontal cerebral lobes
of brain
Contains fossa for
lacrimal gland
Floor
Maxilla and Zygomatic
Maxiallary Sinus
Contains infraorbital
groove and canal for
infraorbital nerve and
artery.
Medial Wall
Ethmoid, Lacrimal,
Frontal, Sphenoid
Ethmoid air cells,
Sphenoid sinus, Nasal
cavity
Contains fossa for
lacrimal sac and
opening of
nasolacrimal canal.
Lateral Wall
Zygomatic, Grater
wing of sphenoid,
Frontal
Temporal fossa
None
(Picture of the bones of the orbit – p. 4 in Netter’s)
External Features of the Eya
 Conjuntiva
o Membrane that cover the eye
 Eyelids – two components
o tarsal plates
 reinforce eyelids
o tarsal glands
 produce fluid to lubricate eyelids

Lacrimal apparatus – consists of three structures
o lacrimal papilla and puncta
o lacrimal canaliculi and sac
o nasolacrimal duct
Openings into the Orbit (7 total)
 Superior Orbital Fissure
o Structures that run through it
 CN III
 CN IV
 CN V-1 (ophthalmic) – three branches: frontal, lacrimal, nasocilliary
 CN VI
 Superior ophthalmic vein
 Optic Canal
o Structures that run through it
 CN II
 Opthalmic Artery
 Anterior and posterior ethmoidal foramina
 Inferior orbital fissure
o Structures that run through it
 CN V-2 – two branches: zygomatic and orbital
 Infraorbital nerve
 Nasolacriaml Duct
 Infraorbital groove
o Structures that run through it
 Infraorbital nerve
 Supraorbital notch
o Structres that run through it:
 Supraorbital nerve
Extrinsic Muscles of the Eye:
Extrinsic Muscles of the Eye
Innervation
Superior oblique
CN IV
Inferior oblique
CN III
Superior rectus
CN III
Inferior rectus
CN III
Medial rectus
CN III
Lateral rectus
CN VI
Levator palpebrae superioris
CN III
Sensory supply to the orbit
 Optic nerve
 Lacrimal nerve
 Frontal nerve
 Nasociliary nerve
 Branches of V-2
Nasal Cavity (p. 172 in supplemental text)
 Three cartilages of the nasal cavity
o Septal
o Lateral
o Alar
 Sensory innervation of the mucous membranes
o Anterior ethmoidal nerves
o Nasopalatine nerves
 Paranasal sinuses
o Air pockets in the bones of the face so that bones will be lighter.
Paranasal Sinus
Paired or Unpaired Opens to:
Nerve Supply
Frontal
Paired
Middle meatus via
fontonasal duct
Supratrochlear nerves
and supraorbital
nerves
Sphenoidal
Paired
Nasal cavity via
sphenoethmoidal
recess
Maxillary nerves and
ethmoidal nerves
Ethmoidal
Three groups of
ethmoidal air cells:
anterior, middle, and
posterior
Anterior and middle
open into middle
meatus. Posterior
opens into superior
meatus
N/A
(Paranasal sinuses pictured on p. 48 in Netter’s)
Nasopharynx
 Located from base of skull to soft palate
 Pharyngeal tonsils embedded in posterior wall (called adenoids when enlarged)
 Contains the Salphingopharyngeal fold (muscle)
o Located from auditory tube cartilage to palatopharyngeus muscle
 Nasopharynx is the opening for:
o Eustachian tube (aka auditory tube)
o Torus tubarius
Oral Cavity (p. 173 in supplemental text)
 Hard Palate
o Makes up anterior 2/3 of the palate
 Soft Palate
o Makes up posterior 1/3 of the palate
 Two types of teeth
o Maxillary
o Mandibular
 Mucous Membranes
o Vestibule
 Located between lips/cheeks and gums/teeth
 Receives parotid duct
o Oral Cavity
o Uvula
 Sensory innervation of mucous membranes
o



2 branches of CN V-2
 Greater and lesser palatine nerves
 Nasopalatine nerves
o 2 branches of CN V-3
 Lingual nerve (floor of mouth)
 Buccal (vestibule and cheek)
Innervation of the Teeth
o Maxillary teeth
 Superior alveolar branches of CN V-2
o Mandibular teeth
 Inferior alveolar branches of CN V-3
Tongue
o Tongue is a mass of skeletal muscles covered by mucosa
o Anterior 2/3 is located in the oral cavity and posterior 1/3 is located in oropharynx
o Sulcus terminalis
 Separates the anterior 2/3 of the tongues from the posterior 1/3 of the tongue.
o Frenulum
 Anchors the underside of the tongue to the oral cavity.
Oropharynx
o Extends from soft palate to upper border of epiglottis
o Contents of the oropharynx
 Palatine tonsils
 Palatopharyngeus muscles
 Elevates the pharynx during swallowing
 Platoglossus muscle
 Depresses the palate
 Tensor veli palanini
 Tenses soft palate
 Levator veli palatine
 Elevates soft palate
 Uvula
Temporal Region (p. 176 in supplemental text)
 Temporal Lines
o Superior
 For attachment of temporalis fascia
o Inferior
 For attachment of temporalis muscle
 Boundaries of the temporal region
o Superior and posterior
 Inferior temporal line
o Anterior boundary
 Frontal process of zygomatic
o Inferior boundary
 zygomatic arch
 Floor of temporal region consists of
o Greater wing of sphenoid
o Squamous temporal bone
o Frontal bone
o Parietal bone
 Contents of the temporal region
o Temporalis muscle
o Deep temporal nerve and arteries


o Zygomaticofactial nerve
Four muscles of mastication (pictured on p. 54 & 55 in Netter’s)
o Masseter
 Elevates and protracts mandible
o Medial pterygoid
 Elevates and protracts mandible (bilaterally)
 Grinding (unilaterally)
o Lateral pterygoid
 Protracts mandible and depresses chin (bilaterally)
 Grinding (unilaterally)
o Temporalis
 Elevates and retracts mandible
o All innervated by mandibular branch of CN V (V-3)
Temporomandibular Joint
o Synovial Joint
o TMJ Ligaments
 Temporomandibular ligament
 Stylomandibular ligament
 Sphenomadibular ligament
Infratemporal Region (p. 176 in supplemental text)
 Boundaries
o Anterior
 Maxilla
o Superior
 Greater wing of sphenoid
o Medial
 Lateral pterygoid plate
o Lateral
 Coronoid process and ramus of mandible
o Inferior
 Continuous with neck (no real boundary)
o Posterior
 TMJ and styloid process
 Contents of the Infratemporal region
o Mandibular nerve
o Maxillary nerve
o Medial and lateral pterygoid muscles
o Lower part of temporalis muscle
o Chorda tympani nerve
o Otic ganglion
Maxillary Artery (Pictured on p. 69 in Netter’s)
 It is the terminal branch of the external carotid artery
 It is divided into three parts by the lateral pterygoid muscle
 First Part of the Maxillary artery
o Goes from origin to lower margin inferior to lateral pterygoid muscle
o 5 arteries come off of first part of maxillary artery
 Deep aricular
 Supplies TMJ, External auditory meatus, and outer surface of ear drum
 Anterior tympanic
 Supplies tympanic cavity and inner surface of ear drum
 Middle meningeal
 Supplies skull and dura mater



Accessory meningeal
 Supplies semilunar ganglion and dura mater
 Inferior alveolar
 Supplies lower teeth and gums
 Passes through the mental foramen on the mandible and becomes the mental artery
Second part of the Maxillary artery
o Branches to the muscles of mastication
o Buccal artery
Third part of the Maxillary artery
o 4 arteries that come off of the third part of the maxillary artery
 Posterior superior alveolar
 Supplies upper molars and premolars
 Infraorbital
 Supplies lower eyelid, side of nose, upper lip, oral mucous
 Descending palatine
 Supplies soft and hard palates
 Artery of pterygoid
 Supplies pharynx and auditory tube.
Anterior Triangle of the Neck
 Borders
o Superior
 Mandible
o Posterior
 Sternocleidomastoid
o Anterior
 Midline of neck
 Subdivisions
o Muscular Triangle
o Submandibular Triangle
o Carotid Triangle
 Contents of the Muscular Triangle
o Ant. and post. bellies of digastric
o Stylohyoid
o Mylohyoid
o Geniohyoid
o Sternohyoid
o Ternothyroid
o Thyrohyoid
o Omohyoid
 Carotid Artery System
o At the bifurcation of the common carotid artery, there are 2 different types of blood monitors:
 Carotid sinus
 Baroreceptor
 Carotid body
 Chemoreceptors
o After the bifurcation, the common carotid artery turns into
 Internal carotid artery (no branches)
 External carotid artery (8 branches)
o Branches of the external carotid artery (Pictured on p. 33 in Netter’s)
 Superior thyroid
 Ascending pharyngeal



 Lingual
 Facial
 Posterior auricular
 Superficial temporal
 Maxillary
Cervical Plexus (p. 186 in supplemental text)
o Derived from ventral rami of C1-4
o Sensory branches of the cervical plexus
 Great Auricular (C2-3)
 Lesser Occipital (C2(3))
 Transverse cervical
 Supraclavicular
o Motor Branches of the cervical plexus
 To prevertebral muscles
 To levator scapulae muscle
 Scalene muscles
o Nerve branches of the cervical plexus
 Ansa cervicalis
 Supplies infrahyoid muscles except thyrohyoid
 Phrenic nerve
o Ansa cervicalis
 Nerve to geniohyoid and thyrohyoid
 Superior and inferior roots supply:
 Omohyoid
 Sternohyoid
 Sternothyroid
Deep Neck
o 7 Components
 Subclavian artery
 Scalene muscles
 Thyroid gland
 Trachea
 Esophagus
 Thoracic duck
 Right lymphatic duct
o Nerves of the deep neckd
 Branches of the Vagus nerve
 Sympathetic trunk
Sympathetic trunk ganglia
o Superior cervical ganglion
o Middle cervical ganglion
o Inferior cervical ganglion
o Stellate ganglion
Pharynx and Larynx (p. 187 in supplemental text)
 Muscles of the paryrnx
o Used in swallowing
 Superior Pharyngeal Constrictor
o Closed by pharyngobasilar fascia
o Traversed by auditory tube
o Forms the tonsilar bed
 Middle Pharyngeal Constrictor
o Traversed by stylopharyngeus muscle and glossopharyngeal nerve









Innervation of the pharynx
o Vagus nerve via pharyngeal plexus (except stylopharyngeus muscle)
o Recurrent laryngeal nerves (to lover part of inferior constrictor)
Blood supply of the pharynx
o Ascending pharyngeal artery
Components of the Laryngeal Skeleton
o Thyroid
o Cricoid
o Arytenoid
o Epiglottis
Thyroid
o 3 components
 Thyrohoid membrane
 Cricothyroid membrane
 Laminae (2 components)
 Superior thyroid notch (adam’s apple)
 Superior and inferior horns
Cricoid
o Lies at the level of C-6
Arytenoid
o Paired
o Support corniculate cartilage
o Contains 2 processes
 Muscular
 Vocal
Epiglottis
o Contains median glosso-epiglottic fold and lateral pharyngo-epiglottic fold
o Valleculae
 Valleys on either side of the glosso-epiglottic fold that is a common site of lodgement.
Laryngeal Cavity and Folds
o 2 folds
 Superior pair
 Inferior pair
o Vestibule
 Lies between the 2 folds
o Vestibular folds
 Sometime called false vocal cords
 Rima vestibule
 Space between vestibular folds
o Ventricular folds
 Referred to as true vocal cords
 Contain vocal ligaments
 Rima glottis
 Space between the vocal folds
 Opens and closes to regulate passage of air
o Infraglottic cavity
 Lies between ventricular folds and lower border of cricoid cartilage
 Continuous with trachea
Innervation of the Larynx
o 3 branches of the Vagus nerve
 External laryngeal branch
 Innervates cricothyroid muscle



Inferior laryngeal branch
 Innervates all remaining muscles of the larynx
 Sensory to mucosa of larynx below vocal folds
 Internal laryngeal branch
 Sensory to mucosa above vocal folds
 Sensory to piriform recess and valleculae
Blood supply of larynx
o Superior laryngeal artery
o Inferior laryngeal artery
Piriform Recess
o Part of laryngopharynx lateral to larynx
 Lateral boundary
 Thyrohyoid membrane and thyroid cartilage
 Medial boundary
 Aryepiglottic fold, arytenoid and cricoid cartilages
o Possible site of lodgement (along with valleculae from above)
Origins, Insertions, Actions and Innervations for block 3 are located in the supplemental text on pages 183, 184,
BLOCK 4
R hypochondrium: liver,
gallbladder
R lumbar: ascending colon
Abdominal
Epigastrium: liver, stomach,
duodenum, pancreas
Umbilical: duodenum,
jejunum, transverse colon
R iliac fossa: ascending colon, Hypogastrium: ileum, sm.
cecum
intestine, bladder, uterus
L hypochondrium: stomach,
spleen
L lumbar: descending colon
L iliac fossa: descending
colon
Inguinal canal:
Males-spermatic cord, vas deferens, ilioinguinal nerve, lymph, arteries, veins, cremaster muscle.
Direct hernias: older men, goes through muscle. Indirect hernias: pass through inguinal canal, more
common than direct hernias, young men
Females-round ligament of uterus, ilioiguinal nerve, lymph
Falciform lig: attaches to liver (largest visceral organ) & diaphragm, round ligament of liver (ligamentum teres
hepatis)
Venous Drainage: above umbilicus drains into azygos; below umbilicus drains into femoral
system via the Great Saphenous vein
Peritoneum is the innermost abdominal lining made of a serous membrane
Portal vein (splenic + superior mesenteric): comes from intestines and goes to liver, nutrient-rich
but low oxygen (don’t confuse with hepatic veins which drain into vena cava)
Portal triad: hepatic artery + bile duct + portal vein
Gallbladder does NOT produce bile; it emulsifies fats to make them transportable
Small intestine: duodenum + jejunum + ileum
Pancreas: produce digestive enzymes (ex. Pepsin), insulin, glucagon, sodium bicarbonate
McBurney’s point: check for appendicitis
Celiac trunk: L gastric artery + splenic artery + common hepatic artery
Inferior vena cava enters abdominal cavity @ T8; esophagus @ T10; aorta @ T12
Rectum ends at S3
Abdominal aorta (T12-L4) branches into common iliac arteries…
Internal iliac
superior/inferior gluteals—above and below piriformis, obturator, lateral sacral, umbilical,
internal pudendal, iliolumbar (Obturator>>acetabular>>lig. Teres which does NOT connect hip
to femur but does go through fovea capitus)
external iliac
inferior epigastric
deep circumflex iliac arteries
**Subcostal Nerve (T12) innervates all abdominal muscles
Vagus Nerve: parasympathetic to L colic flexure and visceral organs
Off of the sympathetic trunk is the greater splanchnic nerves (T5-9) which carry preganglionic,
sympathetic fibers to celiac ganglia
Thigh
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Leg
Anterior compartment= femoral nerve
Medial compartment= obturator nerve
Posterior compartment= sciatic nerve
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Foot
Anterior compartment= deep peroneal
Lateral compartment= superficial peroneal
Posterior compartment= tibial
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Sole= medial and lateral plantar nerves
Dorsum= deep peroneal
Lumbar plexus: T12-L5
*Femoral and Obturator branch off L2-4
Sacral plexus: L4-S4
Nerve injuries:
A) Peripheral: all motor & sensory distal to injury is lost; total loss of muscle, multiple dermatomes lost
B) Nerve root: usually disc herniation superior affects it; 1 dermatome lost, muscle weakness, dorsal OR
sensory lost
Pectineus: supplied by obturator AND femoral nerves
Sciatic Nerve: (common peroneal + tibial) exits through greater sciatic foramen below piriformis
and deep to glut max, also passes b/w greater trochanter and ischial tuberosity
Arteries: External Iliac >>>Femoral (after inguinal ligament) >>>superficial branches or deep femoris
Superficial branches: circumflex iliac, external pudendal, epigastric all pass through saphenous hiatus to
anastomose with respective arteries
Deep femoris: >>>lateral circumflex which gives of 3 terminal branches: ascending,
transverse, and descending genicular arteries(arise in adductor canal)
>>>medial circumflex supplies head/neck of femur
>>>Popliteal (after adductor hiatus)
>>>anterior tibial(runs with deep peroneal nerve)>>>dorsalis pedis>>arcuate, malleolar arteries, deep
plantar, tarsal arteries
>>>posterior tibial(runs with tibial nerve)>>>medial and lateral plantar arteries (circumflex fibular,
peroneal, medial malleolar & calcaneal arteries)
Veins: great saphenous (drains medial side from dorsal venous arch into femoral vein; goes
through femoral triangle)
small/lesser saphenous drains lateral side of dorsal venous arch, runs with the sural nerve in the calf,
empties into popliteal vein—formed by vena commitantes-- which will become the femoral vein at the
adductor hiatus and finally the external iliac vein
Anatomy Block IV Part 2
Gluteal Region
Ligaments:
Obturator Membrane: spans and closes off most of the obturator foramen making the obturator canal allowing passage of the
obturator nerve, artery, and vein.
Sacrospinous Ligament: Runs from the sacrum and coccyx to the ischial spine forming the inferior boarder of the greater sciatic
foramen and the superior boarder of the lesser sciatic foramen.
Sacrotuberous ligament: Runs from posterior iliac spine, lower sacrum, and coccyx to the ischial tuberosity forming the inferior
boarder of the lesser sciatic foramen.
Sacroiliac ligaments: (Anterior and Posterior) Runs for the sacrum to the ilium to support the SI joint.
Iliolumbar Ligament: runs from the transverse processes of L5 to the iliac crest.
Greater Sciatic Foramen: The passageway for structures entering or leaving the pelvis including the piriformis muscle, sciatic nerve,
superior and inferior gluteal artery/vein/nerve, pudendal nerve, internal pudendal artery/vein, posterior femoral cutaneous
nerve, and nerves to quadratus femoris and obturator internus.
Lesser Sciatic Foramen: The passageway for structures entering or leaving the perineum including the tendon of obturator internus,
nerve to obturator internus, pudendal nerve, and the internal pudendal artery/vein.
Cutaneous Innervations:
Each Buttock is divided into 4 quadrants
Upper medial quadrant: Posterior rami of L1-3 (superior clunial nerve) and S1-3 (medial clunial nerve)
Upper lateral quadrant: L1 (Iliohypogastric nerve) and anterior rami of T12
Lower medial quadrant: S1-3 anterior rami (branches from the posterior femoral cutaneous nerve)
Lower lateral quadrant: S2-3 anterior rami (branches form the lateral femoral cutaneous nerve)
Muscles
Posterior gluteal compartment
Gluteus Maximus
Origin: Posterior gluteal line of the ilium, dorsal surface of the sacrum, coccyx and sacrotuberous lig, and from the gluteal
aponeurosis
Insertion: Gluteal tuberosity of the femur and the illiotibial tract
Action: Hip extension and external rotation (needed for rising from a seated position, running, jumping, and climbing, but is
not required for normal walking)
Innervation: L5, S1-2 (inferior gluteal nerve)
Blood supply: Inferior gluteal artery (a branch of the internal iliac artery)
Lateral gluteal compartment
Gluteus medius
Origin: The Ilium between the anterior and posterior gluteal lines, and the gluteal aponeurosis
Insertion: Lateral surface of the greater trochanter
Action: Hip abduction and internal rotation
Innervation: L5, S1 (superior gluteal nerve)
Blood supply: Superior gluteal artery (a branch of the internal iliac artery)
Gluteus minimus:
Origin: The ilium between the anterior and inferior gluteal lines
Insertion: Anterior boarder of the greater trochanter
Action: Hip abduction and internal rotation
Innervation: L5, S1 (superior gluteal nerve)
Blood supply: Superior gluteal artery (a branch of the internal iliac artery)
Tensor Fascia Latae
Origin: Outer lip of the iliac crest and ASIS
Insertion: The iliotibial tract
Action: Flexion, abduction and internal rotation of the hip
Innervation: L5, S1 (superior gluteal nerve)
Blood supply: Superior gluteal artery (a branch of the internal iliac artery)
Deep external Rotators
Piriformis – leaves the pelvis through the greater sciatic foramen and divides it into superior and inferior portions.
Origin: Internal surface of sacral vertebrae S2-4, sacrotuberous lig, and the ilium below PIIS
Insertion: Upper boarder of the greater trochanter
Action: Hip External rotation, and abduction of a flexed thigh
Innervation: ventral rami S1-2
Gemellus superior
Origin: Ischial spine
Insertion: Medial surface of the greater trochanter and the upper margin of the obturator internus tendon.
Action: Hip External rotation
Innervation: L5, S1 (nerve to obturator internus)
Obturator internus
Origin: Inner surface of the obturator membrane and the edges of the obturator foramen
Insertion: Medial surface of the greater trochanter
Action: Hip external rotation, can help to abduct a flexed hip
Innervation: L5, S1 (nerve to obturator internus)
Gemellus inferior
Origin: Ischial tuberosity
Insertion: Medial surface of the greater trochanter and the lower margin of the obturator internus tendon.
Action: Hip external rotation
Innervation: L5, S1 (never to quadratus femoris)
Obturator Externus
Origin: External surface of the obturator
membrane and
the edges of the obturator foramen
Insertion: Trochanteric Fossa
Action: Hip external rotation
Innervation: L3-4 (obturator nerve)
Quadratus Femoris
Origin: Ischial tuberosity
Insertion: Intertrochanteric crest
Action: Hip external rotation
Innervation: L5, S1 (nerve to quadratus femoris)
Blood Supply to the Gluteal Region
Branches of the Internal Iliac Artery
Superior Gluteal Artery
Inferior Gluteal Artery
Pudendal artery
Branches of the femoral artery
Medial femoral circumflex artery
Lateral femoral circumflex artery
Bursae of the Gluteal Region
Trochanteric bursa
Gluteofemoral bursa
Ischial (Sciatic) bursa
The Hip Joint
Bony Articulations
Synovial ball and socket: The convex femoral head articulates with the acetabulum at the lunate surface. This particular joint
favors stability over mobility and allows for 3-degrees of freedom. The non-articular depression in the center of the
actebulum is the acetabular fossa.
Ligaments and Joint Capsule
The 2 ends of the lunate surface are separated by the acetabular notch. The acetabular notch is spanned by the transverse
acetabular ligament which is a continuation of the acetabular labrum in this space. The transverse acetabular ligament
converts the notch into a foramen that transmits the artery to the head of the femur.
The acetabular labrum is a fibrocartilage pad that covers the rim of the acetabulum. Its purpose is to deepen the acetabular
socket and help support the femoral head.
The fibrous joint capsule attaches from the acetabulum and transverse acetabular ligament to the greater trochanter and
intertrochanteric line.
The Iliofemoral ligament (also called the “y” ligament of Bigelow) is shaped like an inverted “y”. It attaches from the AIIS to the
intertrochanteric line and resists hyperextension of the hip.
The pubofemoral ligament attaches from the pubis near the inferior rim of the acetabulum to the neck of the femur above the
lesser trochanter. It limits hip abduction and also resists hyperextension.
The ischiofemoral ligament attaches from the ischium near the posterior rim of the acetabulum to the neck of the femur medial
to the greater trochanter. It resists hyperextension of the hip.
The ligament of the head of the femur (ligamentum teres) attaches from the transverse acetabular ligament to the fovea of the
head of the femur. It serves to support the artery to the femoral head.
The zona orbicularis is a collar-like ligament around the distal neck of the femur.
Nerve supply to the hip joint is mostly from branches of the femoral and obturator nerves with additional branches from the sciatic
never and sacral plexus.
Blood Supply
The main blood supply of the hip joint is from small branches of the medial femoral circumflex artery, lateral femoral circumflex
artery, obturator artery, and gluteal arteries. The femoral head is supplied by a small branch of the obturator artery that is
part of the neurovascular bundle supported by the ligamentum teres.
Angulations of the Hip
Angle of inclination: The angel of the axis of the femoral neck to the axis of the femoral shaft. Normally 150° in infants, 125° in
adults, and 120° in the elderly.
Pathologies: Coxa valga is in increased angle of inclination, and coxa vara is a decreased angle.
Angle of torsion: The angle between the transverse axis of the femoral condyles and the axis of the femoral neck. The normal
range is from 8-25° with 12° being the average.
Pathologies: Anteversion is an increase in this angle causing the anterior surface of the femur to point more medially.
Retroversion is a decreased angel causing femur to face more laterally.
The Thigh and the Femoral Triangle
The Femoral Triangle
Boarders: medial border of the sartorius muscle, medial border of the adductor longus muscle, and the inguinal ligament. The
floor of the femoral triangle consists of the iliopsoas, pectineus, and adductor longus muscles.
Contents (laterally to medially): Femoral nerve, femoral artery, femoral vein, lymphatics (lymph is within the femoral canal)
(femoral artery/vein and lymph are in femoral sheath, but NOT the femoral nerve)
Anterior Compartment of the Thigh
The fossa ovalis (saphenous opening) and cribiform fascia is a portion of fascia in the anterior thigh that is highly perforated by
the saphenous vein and other blood and lymphatic vessels.
The adductor canal: This is the passageway from the anterior to posterior compartments of the thigh. The lateral border is
vastus medialis, the posterior border is adductor longus and magnus, and the anteromedial border is sartorius. The
contents of the adductor canal are the saphenous nerve (terminal femoral nerve), nerve to vastus medialis, terminal
part of the obturator nerve, the terminal part of the femoral artery/vein, and deep lymphatic vessels. The canal ends at
the adductor hiatus (space between adductor magnus and femur) which is the point where the femoral artery/vein are
renamed the popliteal artery/vein. These 2 vessels are the only structures that travel completely through the adductor
canal.
Muscles – all muscles in the anterior thigh compartment are innervated buy the femoral nerve (spinal levels with specific
muscles).
Iliopsoas - 2 muscles (iliacus & psoas major)
Common insertion: the lesser trochanter
Iliacus – L2-3 (via femoral nerve)
Origin: Upper part of iliac fossa, ala of the sacrum, and the adjacent ligaments
Action: Hip flexion
Psoas Major – L1-3 (directly from spinal nerves)
Origin: Lumbar vertebral bodies, intervertebral discs, and transverse processes
Action: Hip flexion, lumbar lateral flexion and stabilization
Sartorius – L2-3
Origin: On and just inferior to the ASIS
Insertion: Upper part of the medial surface of the tibia
Action: Hip flexion, abduction, and external rotation. Knee flexion and internal rotation
Pectineus – L2-3
Origin: Pectineal line of the pubis (superior ramus)
Insertion: upper half of the pectineal line of the femur
Action: Hip abduction, flexion, and internal rotation
Quadriceps – L2-4
Common insertion: Tibial tuberosity via the patellar ligament
Common Action: Knee Extension
Rectus femoris
Origin: AIIS and the posterosuperior rim of the acetabulum
Additional Action: Hip flexion
Vastus lateralis
Origin: The upper region of the intertrochanteric line, greater trochanter, gluteal tuberosity, and the lateral lip of
the linea aspera
Vastus medialis
Origin: The lower region of the intertrochanteric line, medial lip of the linea aspera, medial supracondylar line, and
fibers from the adductor magnus muscle.
Vastus intermedius
Origin: The anterior-lateral region of the upper 2/3 of the femoral shaft
Medial Compartment of the Thigh
Muscles – The muscles in the medial compartment are mostly hip adductors and are innervated by the obturator nerve with 1
exception.
Gracilis
Origin: The front of the body and inferior ramus of the pubis
Insertion: The upper part of the medial surface of the shaft of the tibia
Action: Hip adduction; knee flexion, and tibial internal rotation
Innervation: L2-3 (obturator nerve)
Adductor longus
Origin: The crest and symphysis of the pubis
Insertion: medial lip of the linea aspera
Action: Hip adduction, flexion, and internal rotation
Innervation: L2-4 (Obturator nerve)
Adductor brevis
Origin: The body and inferior ramus of the pubis
Insertion: The pectineal line and upper part of the linea aspera of the femur
Action: Hip adduction, flexion, and internal rotation
Innervation: L2-4 (Obturator nerve)
Adductor magnus
Origin: Ischial tuberosity and ischiopubic ramus
Insertion: Adductor component – the gluteal tuberosity, medial lip of the linea aspera, and the medial supracondylar
line. Hamstring component – the adductor tubercle
Action: Hip adduction; the upper fibers flex and internally rotate hip; lower fibers extend and externally rotate hip
Innervation: L2-4 (Adductor component via obturator nerve; Hamstring component via the tibial branch of the sciatic
nerve)
Obturator externus: (See Gluteal Region Notes)
Posterior Compartment of the Thigh
Muscles – Mostly responsible for hip extension and knee flexion. Innervated by the sciatic nerve (tibial or common fibular)
Biceps Femoris
Common insertion: Lateral side of fibular head and lateral tibial condyle
Common action: Knee flexion and tibial external rotation
Long head
Origin: Ischial tuberosity and lower sacrotuberous ligament.
Additional action: Hip extension
Innervation: L5, S1-2 (Tibial portion of sciatic nerve)
Short head
Origin: Lateral lip of the linea aspera, and upper part of the lateral supracodylar line
Innervation: L5, S1-2 (Common Fibular portion of sciatic nerve)
Semimembranosus
Origin: Ischial tuberosity and adjacent ischial ramus
Insertion: posteromedial aspect of the medial tibial condyle
Action: flexion and internal rotation of the knee, and hip extension
Innervation: L5, S1-2 (Tibial portion of sciatic nerve)
Semitendinosus
Origin: Common origin from the Ischia tuberosity with the long head of biceps femoris
Insertion: Upper part of the medial surface of the tibia
Action: flexion and internal rotation of the knee, and hip extension
Innervation: L5, S1-2 (Tibial portion of sciatic nerve)
Cutaneous Innervations of the Thigh is via the anterior, posterior, and lateral femoral cutaneous nerves, and the obturator nerve.
Blood Supply in the Thigh
Femoral Artery
Superficial circumflex iliac artery.
Superficial epigastric artery.
Superficial external pudendal artery
Deep external pudendal artery.
Descending genicular artery
Deep femoral artery (profunda femoris)
Lateral femoral circumflex artery.
Medial femoral circumflex artery.
Perforating arteries (3 plus termination of deep femoral artery)
Obturator artery
Pes Anserinus means goose’s foot and is located at the proximal medial tibia at the insertion of Sartorius, gracilis, and
semitendinosus.
The Popliteal fossa:
Boundaries:
Superior lateral border – biceps femoris muscle
Superior medial border – semimembranosus and semitendinosus muscles
Two inferior borders – medial and lateral heads of gastrocnemius
Floor – Popliteal surface of the femur
Contents: (Deep to superficial) The popliteal artery, popliteal vein, and tibial nerve. Lymphatics, the common fibular nerves, the
small saphenous vein, and the popliteal bursa are also found in the popliteal fossa.
The popliteal artery is a continuation of femoral artery that begins at the adductor hiatus and ends at the lower border of the
popliteus muscle where it splits into the anterior and posterior tibial arteries.
The Popliteal vein is formed by the junction of venae comitantes of the anterior and posterior tibial arteries at the lower border
of the popliteus muscle. It receives blood from the lesser saphenous vein and is renamed the femoral vein at the
adductor hiatus.
The tibial nerve is part of the sciatic nerve that supplies the posterior leg and thigh. The medial sural cutaneous nerve arises
from tibial nerve in the popliteal fossa and is later joined by the lateral sural cutaneous nerve (a branch of the common
fibular nerve) where it becomes the sural cutaneous nerve.
The common fibular nerve is also part of the sciatic nerve. It pierces the fibularis longus muscle and divides into the superficial
and deep fibular nerves which supply the lateral and anterior leg compartments respectively.
Genicular anastomosis is formed by interconnecting arterial branches from above and below the knee.
Descending genicular artery from the femoral artery.
Descending branch of the lateral femoral circumflex artery.
Genicular branches of the popliteal artery:
Medial superior/inferior genicular arteries.
Lateral superior/inferior genicular arteries.
Middle genicular artery.
Branches of anterior tibial artery:
Circumflex fibular.
Anterior tibial recurrent.
Posterior tibial recurrent artery branches from the posterior tibial artery.
The Leg
Bones of the Leg
The tibia has a relatively poor blood supply and is the most common long bone to be fractured. The anteromedial surface is
“bare”, and available for bone grafts
The Fibula is the lateral bone of the leg. The lateral maleolus of the fibula is important for ankle stability.
The Crural fascia is the fascia in the leg that is continuous with the fascia lata of the thigh. The crural fascia from the various
retinacula of the foot.
Superior (extensor) retinaculum is proximal to the malleoli and binds tendons in anterior crural compartment
Inferior (extensor) retinaculum is “Y”-shaped attaching from the calcaneus in front of the ankle to the medial maleolus and
plantar aponeurosis which binds the extensor tendons of the foot and ankle.
Flexor retinaculum goes from the medial maleolus to the calcaneus and binds the tendons of tibialis posterior, flexor digitorum
longus, and flexor hallucis longus along with the tibial nerve and posterior tibial vessels.
Superior/inferior peroneal retinacula go from the lateral maleolus to the lateral surface of the calcaneus and bind the tendons
of peroneus longus and brevis.
The Superficial posterior compartment of the leg contains the medial sural nerve, lateral sural nerve, and the combined sural nerve
running with the lesser saphenous vein. The sural nerve supplies the skin of the lateral and posterior part of the inferior 3 rd
of the leg and lateral side of foot. The muscles of this compartment are the gastrocnemius, soleus, and plantaris. The 2
head of gastrocnemius and soleus together are called the Triceps surae. These muscles function mainly to flex the knee and
plantarflex the ankle through their common insertion at the Achilles tendon. The tibial nerve supplies all the muscles in the
posterior compartment of the leg, and divides into the medial and lateral plantar nerves posterior and inferior to the medial
malleolus.
Muscles of the superficial posterior compartment of the leg
Gastrocnemius: medial (larger) and lateral heads – The lateral head may have a sesamoid bone called the fabella
Origin: The medial head originates from the medial condyle and adjacent part of femur; the lateral head originates
from the lateral femoral condyle and the posterior surface of the femur immediately superior to the condyle
Insertion: posterior part of calcaneus via the calcaneal tendon
Action: Ankle plantarflexion; knee flexion
Innervation: tibial nerve; S1-2
Plantaris: May be absent in some people. Its tendon may be used for hand surgery
Origin: lateral supracondylar ridge of femur (superior to the lateral head of the gastrocnemius)
Insertion: calcaneal tendon
Action: plantarflexion; weak knee flexion
Innervation: tibial nerve; S1-2
Soleus: This broad multipennate muscle does not cross the knee
Origin: Fibular head and upper part of posterior surface of fibular shaft and the soleal line of tibia
Insertion: calcaneal tendon
Action: plantarflexion
Innervation: tibial nerve; S1-2
The deep posterior compartment of the leg contains 4 muscles (tibialis posterior, flexor digitorum longus, flexor hallucis longus, and
popliteus) that are all innervated by the tibial nerve.
Muscles of the Deep posterior compartment of the leg
Popliteus: Lies in the floor of the popliteal fossa.
Origin: Lateral femoral condyle and posterior aspect of the lateral meniscus
Insertion: posterior aspect of the tibia above the soleal line
Action: Knee flexion; externally rotates the femur when foot is fixed
Innervation: Tibial nerve; L4-5, S1
Flexor digitorum longus: Its tendon passes posterior to the tendon of the tibialis posterior muscle behind the medial
malleolus
Origin: middle half of tibia below soleal line
Insertion: Bases of distal phalanx of digits 2-5
Action: DIP flexion; ankle plantarflexion
Innervation: tibial nerve; S2-3
Flexor hallucis longus: Its tendon runs in the shallow groove on the posterior surface of the talus. Its tendon is deep to the
tendon of flexor digitorum longus and extends between the 2 sesamoid bones of flexor hallucis brevis. This is the
most important muscle for the push-off stroke during walking, jumping, and running.
Origin: Distal 2/3 of the posterior fibula
Insertion: Plantar aspect of the base of the distal phalanx of the great toe
Action: DIP flexion of great toe; ankle plantarflexion
Innervation: tibial nerve; S2-3
Tibialis posterior: This muscle helps to maintain the medial longitudinal arch
Origin: Posterior surface of the interosseous membrane, lateral portion of the tibial shaft, and upper 2/3 of fibula
Insertion: navicular tuberosity, sustentaculum tali, 3 cuneiforms, cuboid, and bases of metatarsals 2-4
Action: Ankle inversion and plantarflexion
Innervation: tibial nerve; L4-5
The anterior compartment of the leg contains 4 muscles (tibialis anterior, extensor hallucis longus, extensor digitorum longus, and
peroneus tertius) that are all innervated by the deep fibular nerve, and function mainly to dorsiflex the ankle and extend
the digits. The deep fibular nerve runs along with the anterior tibial artery between extensor hallucis longus and tibialis
anterior muscles.
Muscles of the anterior compartment of the leg
Tibialis anterior:
Origin: lateral condyle of the tibia, upper 2/3 of the tibia shaft and interosseous membrane
Insertion: Medial cuneiform and base of first metatarsal
Action: dorsiflexion and inversion of foot
Innervation: deep fibular nerve; L4-5
Extensor digitorum longus:
Origin: lateral condyle of the tibia, upper 3/4 of the shaft of fibula and interosseous membrane
Insertion: the membranous expansion on dorsum of toes 2-5, the central slip inserts onto the base of the middle
phalanx and the 2 lateral slips converge to insert onto the base of the distal phalanx. Lumbricals and interossei
insert onto these expansions
Action: MP Extension; ankle dorsiflexion; foot eversion
Innervation: deep fibular nerve; L4-5
Fibularis tertius: This is part of the extensor digitorum longus and may be absent in some people
Origin: lower 1/4 of the anterior surface of the fibula and interosseous membrane
Insertion: Dorsal surface of the 5th metatarsal
Action: Ankle dorsiflexion and foot eversion
Innervation: Deep fibular nerve; L4-5
Extensor hallucis longus
Origin: Middle ½ of the fibula and interosseous membrane
Insertion: Base of the distal phalanx of the great toe
Action: IP Extension of the great toe; aids in ankle dorsiflexion
Innervation: Deep fibular nerve; L4-5
The lateral compartment of the leg contains the peroneus (fibularis) longus and brevis muscles which are innervated by the
superficial fibular nerve. The major functions of these muscles are eversion and plantarflexion.
Muscles of the lateral compartment of the leg
Fibularis longus: This is the more superficial of the 2 muscles in this compartment. Its tendon passes posterior to the lateral
malleolus, and obliquely crosses the sole of the foot to its insertion.
Origin: head of fibula, upper 2/3 of the fibular shaft
Insertion: Base of the first metatarsal and the medial cuneiform
Action: ankle plantarflexion and foot eversion; depresses first metatarsal
Innervation: superficial fibular nerve; L5, S1-2
Fibularis brevis
Origin: lower 2/3 of fibula
Insertion: base of 5th metatarsal
Action: foot eversion; weak ankle plantarflexion
Innervation: superficial fibular nerve; L5, S1-2
The Dorsum of the foot contains the extensor hallucis brevis, extensor digitorum brevis, and the dorsal interosseous muscles. This
region is innervated by the deep fibular nerve and lateral plantar nerve (dorsal interossei), with additional cutaneous
innervation from the superficial fibular and sural nerves.
Muscle of the dorsum of the foot
Extensor digitorum brevis
Origin: anterior part of dorsum of calcaneus and inferior extensor retinaculum
Insertion: lateral sides of extensor digitorum longus tendons for digits 2-4
Action: PIP extension of digits 2-4
Innervation: deep fibular nerve; L5, S1
Extensor hallucis brevis: Often considered to be part of extensor digitorum brevis
Origin: same as extensor digitorum brevis
Insertion: dorsal surface of base of first phalanx of great toe
Action: extends MP joint of digit 1
Innervation: deep fibular nerve; L5, S1
Dorsal interossei
Origin: each of the 4 muscles arises by 2 heads from adjacent sides of metatarsals b/t which they are placed
Insertion: 1st interosseous inserts onto medial side of base of proximal phalanx of 2nd digit, interossei 2-4 insert onto
lateral sides of bases of proximal phalanges of digits 2-4.
Action: abduction of digits 2-4 at the MP joints; MP flexion and PIP/DIP extension of digits 2-4.
Innervation: lateral plantar nerve: S2-3
Blood supply of the leg and foot
Posterior tibial artery is the largest branch of popliteal artery and divides into medial and lateral plantar arteries.
Anterior tibial artery begins at the inferior border of popliteus muscle, and becomes the dorsalis pedis artery at the ankle joint.
Peroneal artery is a branch of the posterior tibial artery that supplies the lateral compartment muscles, popliteus, and other
muscles in the posterior compartment.
The Knee
Tibiofemoral Joint is a modified hinge joint.
The femoral condyles are convex and asymmetric. The medial condyle is larger than lateral condyle. The condyles are separated
anteriorly by the patellar groove, and posteriorly by the intercondylar fossa.
The tibial plateaus are concave and also asymmetric. The articular surface of the medial plateau is 50% larger than the lateral
plateau, and the plateaus are separated by the intercondylar tubercles.
The menisci are wedge-shaped fibrocartilaginous joint discs, and the ends of the menisci (horns) are attached to the tibial
intercondylar tubercles. Coronary ligaments attach the menisci to the tibial plateaus. The menisci are joined by an
anterior transverse ligament allowing them to move together. The menisci function to enhance the stability of the knee
joint by deepening the articulating surfaces of the tibia. They help with weight distribution, and also reduce friction
within the joint. The menisci are also poorly vascularized a do NOT heal well
The medial meniscus is larger than the lateral and more securely attached, and also attaches to the medial collateral
ligament and semimembranosus muscle. The Medial meniscus is more commonly injured. The medial meniscus
moves posteriorly during flexion due to tension in semimembranosus muscle, and it moves anteriorly during
extension due to tension in anterior capsular fibers.
The lateral meniscus is attached to the popliteus muscle and also to the posterior cruciate ligament via the meniscofemoral
ligament. During flexion the lateral meniscus is drawn posteriorly due to tension in popliteus expansion. The lateral
meniscus distorts more than medial meniscus during flexion and extension.
The knee joint capsule is large and lax with many recesses (bursae). The capsule is deficient on the lateral condyle to allow for
passage of popliteal tendon, and the anterior wall of the capsule is replaced by the quadriceps tendon. The cruciate
ligaments are NOT included within the synovium of the capsule.
There are many bursae associated with the knee, some of which communicate with the synovial cavity.
Suprapatellar bursa – superior to the patella between the femur and quadriceps muscle and tendon. It communicates with
the joint cavity of knee.
Prepatellar bursa – between the patella and the skin.
Deep infrapatellar bursa – inferior to patella between the patellar ligament and the tibia.
Subcutaneous infrapatellar bursa – between the patellar ligament and the skin.
Subpopliteal bursa – located between the tendon of popliteus and the tibia. It communicates with the knee joint cavity.
Gastrocnemius bursa – under the medial head of gastrocnemius. It also communicates with the knee joint cavity.
Anserine bursa – between pes anserinus and the medial collateral ligament.
Ligaments of the Knee
Medial (tibial) collateral ligament attaches to the proximal tibia and medial femoral epicondyle. It is continuous with the
adductor magnus tendon and is attached to the medial meniscus.
Lateral (fibular) collateral ligament splits the tendon of biceps femoris muscle and is separated from the lateral meniscus
by the popliteus tendon.
Anterior Cruciate ligament (ACL) attaches from the anterior tibia to the lateral femoral condyle. It is slack during flexion
and taught during extension, and it prevents backward displacement of femur on the tibia and hyperextension of
knee joint. It is weaker than the PCL.
Posterior cruciate ligament (PCL) attaches from the posterior tibia to the medial femoral condyle. It is taught during flexion
and slack during extension, and it prevents forward displacement of femur (hyperflexion) or backward
displacement of tibia.
The arcuate popliteal ligament extends from the posterior part of head of fibula and then bifurcates to attach to the
posterior part of lateral femoral condyle and to intercondylar area of tibia
Movements of the knee
Flexion: The first part of flexion from full extension (0-25 degrees) consists of posterior rolling and spinning followed by anterior
sliding of femoral condyles on tibial plateaus
Extension: At beginning of extension, the femoral condyles roll anteriorly while sliding posteriorly, followed by rolling and
spinning of the femoral condyles.
Lateral and medial rotation of tibia: At 90° of flexion there is up to 40° of lateral rotation and 30° of medial rotation of the tibia.
The amount of rotation decreases as flexion increases past 90°.
Locking at Full Extension: During the final few degrees of extension the femur rotates medially on the tibia “locking” the knee
into the close packed position. Popliteus laterally rotates femur for unlocking at beginning of knee flexion.
Axes of the Knee
The mechanical axis is represented by a line drawn from head of femur to the superior surface of head of talus and is almost
equivalent to the axis of the tibia.
The anatomic axis is represented by a line drawn along femoral shaft.
The femoral and tibial axes converge to form a normal angle of 170-175° (This is called physiologic valgus). Genu valgum is a
decrease in this angle, and genu varum is an increase in this angle.
The Q angle is formed by resultant vector of the quadriceps (line from ASIS to the idle of patella) and the line of pull of the
patellar ligament (line from tibial tubercle to middle of patella). The normal Q angle is 15 deg.
The Patellofemoral Joint
The patella is a sesamoid bone within the quadriceps tendon. During flexion and extension the central ridge of the patella slides
along central groove of femur.
During flexion the patella glides distally as it is pulled by the patellar ligament attached to the tibia.
During extension the patella glides proximally as it is pulled by the quadriceps muscles. Vastus lateralis tends to pull the
patella laterally, and vastus medialis oblique (VMO) counteracts vastus lateralis.
Innervation and Vasularization of the Knee
The articular nerves are branches of the obturator, femoral, tibial, and common peroneal nerves. The blood supply is via
genicular anastomoses.
The Ankle and Foot
Division of the Foot:
Hindfoot (posterior segment): Talus and Calcaneus
Midfoot (middle segment): Navicular, Cuboid, and Cuneiforms
Forefoot (anterior segment): Metatarsals and Phalanges
Plantar Arches
Longitudinal: Medial and lateral arches
Pathologies: Pes cavus (high arch) and pes planus (flat foot)
Transverse arch
The Support ligaments for these arches include the spring ligament (primary support for medial longitudinal arch), long plantar
ligament (primary support for lateral longitudinal arch), the plantar aponeurosis, short plantar ligament, and the
marginal abductors.
Joints of the Ankle and Foot
Superior tibiofibular joint is a synovial plane joint with a capsule
Inferior tibiofibular joint is a syndesmosis joint supported by the posterior tibiofibular ligament, anterior tibiofibular ligament,
and the crural tibiofibular interosseous ligament
Talotibial joint (talocrural) (“Ankle”) is a synovial hinge joint responsible for dorsiflexion and plantarflexion. This joint is
supported medially by the medial collateral (deltoid) ligament which consists of the tibionavicular, tibiocalcanean,
anterior tibiotalar, and posterior tibiotalar ligaments. It is supported laterally by the lateral collateral ligament which
consists of the anterior talofibular ligament, posterior talofibular ligament, and the calcaneofibular ligament. This joint
is also considered a mortise and tenon joint with the mortise consisting of the fibular malleolus, tibial malleolus, and
the distal end of tibia, and the tenon being the head of the talus.
Talocalcaneal (subtalar) joint is a very stable, uniaxial, triplanar joint that is responsible for inversion and eversion. The joint has
3 surfaces consisting of the posterior articulation (concave talus on convex calcaneus) and the anterior articulations
(Convex facets of talus on the concave facets of the calcaneus) which are separated by the tarsal tunnel containing the
interosseous talocalcaneal ligament. The joint is also supported by the posterior and lateral talocalcaneal ligaments.
Talocalcaneonavicular joint consists of the talocalcaneal and the talonavicular joints, and also contributes to inversion and
eversion. These joints are supported by the calcaneonavicular (spring) ligament which runs from the sustentacular tali
to inferior navicular and helps to maintain the medial longitudinal arch of the foot.
Calcaneocuboid joint is a triplanar joint supported by the short plantar and long plantar ligaments.
Transverse tarsal joint consists of the talonavicular and calcaneocuboid joints, and it contributes to add to the inversioneversion range. It keeps the distal foot inverted when lateral surface is in contact with the ground while the hindfoot is
everted.
The Cuneonavicular, Tarsometatarsal, PIP, and DIP joints are all self explanatory.
Layers and Muscles of the Sole of the foot:
The First Layer of the Foot contains the plantar aponeurosis, and the following muscles.
Abductor hallucis
Origin: calcaneal tuberosity
Insertion: medial sesamoid and base of proximal phalanx of great toe
Action: abducts great toe at MP joint, and helps flex MP joint
Innervation: medial plantar nerve; S2-3
Flexor digitorum brevis
Origin: calcaneal tuberosity
Insertion: Middle phalanx of digits 2-5
Action: PIP flexion of digits 2-5
Innervation: Medial plantar nerve; S2-3
Abductor digiti minimi
Origin: calcaneal tuberosity
Insertion: Proximal phalanx of the digit 5
Action: MP abduction of digit 5
Innervation: Lateral plantar nerve; S2-3
The Second Layer of the Foot contains the tendons of flexor digitorum longus and flexor hallucis longus along with the following
muscles.
Quadratus plantae
Origin: The plantar surface of calcaneus
Insertion: lateral edge of the tendon of flexor digitorum longus
Action: may help DIP flexion of digits 2-5
Innervation: Lateral plantar nerve; S2-3
Lumbricals
Origin: 1st lumbrical arises from the long tendon of the 2nd digit; the 3 lateral lumbricals arise in the intervals between
the adjacent long flexor tendons
Insertion: The extensor expansion on the medial side of the proximal phalanges of digits 2-5
Action: MP flexion and PIP/DIP extension of digits 2-5
Innervation: lumbricals 2-4 by the lateral plantar nerve (S2-3) and lumbrical 1 by the medial plantar nerve (S2-3)
The third layer of the foot consists of the following muscles
Flexor hallucis brevis: This muscle has 2 bellies with 2 sesamoid bones sitting on either side of the flexor hallucis longus
tendon.
Origin: plantar surface of cuboid and lateral cuneiform
Insertion: base of proximal phalanx of digit 1
Action: MP flexion of digit 1
Innervation: medial plantar nerve; S2-3
Adductor hallucis:
Origin: oblique head from the bases of metatarsals 2-4 and the sheath of peroneus longus; transverse head from the
plantar metatarsophalangeal ligaments of digits 2-4
Insertion: base of the proximal phalanx of the great toe with flexor hallucis brevis
Action: great toe adduction at the MP joint
Innervation: lateral plantar nerve; S2-3
Flexor digiti minimi brevis:
Origin: the base of 5th metatarsal and the sheath of peroneus longus
Insertion: base of proximal phalanx of digit 5
Action: PIP flexion of digit 5
Innervation: lateral plantar nerve; S2-3
The Forth Layer of the Foot consists of tendon of peroneus longus and tibialis posterior, and the following muscles.
Dorsal interossei (4):
Origin: adjacent sides of metatarsals 1-5
Insertion: 1st interosseous inserts onto medial side of base of proximal phalanx of 2nd toe, 2-4 insert onto the lateral
sides of the bases of the proximal phalanx of digits 2-4.
Action: abduction of digits 2-4 at the MP joints; MP flexion
Innervation: lateral plantar nerve; S2-3
Plantar interossei (3):
Origin: each head arises from the medial side of the base of each metatarsal 3-5 and from the sheath of peroneus
longus
Insertion: Medial side of the base of the proximal phalanx of the same digit
Action: adducts digits 3-5 at MP joints; MP flexion and PIP/DIP extension of digits 3-5
Innervation: Lateral plantar nerve: S2-3