LECTURE 1 - INTRODUCTION AND BACK
INTRODUCTION:
In this course we take a regional anatomy approach to studying the human body. What
this means is that we study the anatomy of the human body in major parts or segments:
1. A main body consisting of the head, neck and trunk (subdivided into head,
thorax, abdomen, back and pelvis and perineum)
2. Upper extremity
3. Lower extremity
Anatomical positions:
 Upright – all joints in 0 degrees (except forearm)
Body planes:
1. Median plane (midsagital plane) – vertical plane passing longitudinally through
the body, divides the body into equal left and right halves. Defines midline of
head, neck and trunk.
2. Sagittal planes – vertical planes passing through the body parallel to the median
plane.
3. Frontal planes – vertical planes passing through the body dividing into anterior
and posterior parts.
4. Transverse planes – horizontal planes passing through the body dividing the
body into superior and inferior parts.
Sections of body:
1. appendicular skeleton:
 upper limb - arm vs. forearm
 lower limb - thigh vs. leg
2. axial skeleton:
 skull
 thoracic cage
 vertebral column
Terms of relationship and comparison:
 superior vs. inferior; cranial vs. caudal
 posterior vs. anterior
 medial vs. lateral
 dorsal vs. ventral; dorsal vs. palmer; dorsal vs. plantar
 superficial vs. intermediate vs. deep
 proximal vs. distal
Terms of movement:
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley





flexion vs. extension
supination vs. pronation
abduction vs adduction
lateral rotation vs. medial
rotation
retraction vs. protraction




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dorsiflexion vs. plantar flexion
inversion vs. eversion
elevation vs depression
opposition vs reposition
retraction vs. protraction
Types of joints:

Plane- permit gliding or sliding movements

eg: acromioclavicular joint

Hinge- permits flexion and extension only

eg: elbow joint

Saddle- permits movement in two different planes

eg: carpometacarpal joint

Condyloid- permits flex/extend, abduct/adduct, and circumduction.

eg: metacarpophalangeal joint

Ball-and-Socket-permits multiaxial movement; flex/extend, abduct/adduct,
medial/lateral rotation, and circumduction

eg: hip joint

Pivot- permits rotation around a central axis.
 eg: atlanto-axial joint
Common and acceptable abbreviations:
muscle = m.
muscles = mm.
nerve = n.
nerves = nn.
artery = a.
arteries = aa.
vein = v.
veins = vv.
THE BACK: VERTEBRAL COLUMN AND ITS CONTENTS
SURFACE ANATOMY:
1.
2.
3.
4.
5.
6.
7.
posterior median furrow: when the back is not being flexed or the scapulae are not
protracted the tips of the spinous processes lie deep to it. It ends as flattened triangle
over the sacrum.
intergluteal cleft: inferior continuation of posterior median furrow; created by gluteal
muscles and fat.
nuchal groove: superior continuation in neck, overlies nuchal ligament (ligamentum
nuchae).
vertebra prominens: visible at the base of the neck, inferior to nuchal groove. It is the
spinous process of the C7 vertebra.
erector spinae: prominent vertical bulges, help to form posterior median furrow caudally,
laterally end at angles of ribs in thoracic region.
trapezius, latissimus dorsi, teres major: superficial muscles of the back and scapuladeltoid region that can be seen especially in muscular individuals
vertebral border, inferior angle and spine of scapula: can be seen especially in lean
individuals.
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley
8.
supraspinous ligament: ligament that overlies spinous processes of vertebrae. Can be
palpated in median longitudinal furrow.
9. spinous processes of lumbar vertebrae: palpated in posterior median furrow
10. posterior superior iliac spines: create dimples (in some individuals) superior and lateral to
gluteal cleft. A line connecting them overlies S2 vertebra.
BONY FEATURES:
Vertebral Column:
 24 individual vertebrae: 7 cervical, 12 thoracic, 5 lumbar
 segmentation: 33 vertebrae of early development reduce to 26 bones
 5 sacral vertebrae fuse producing the sacrum
 4 coccygeal vertebrae fuse producing the coccyx
1. Curvatures:
 Primary There are two, which develop during the fetal period and are concaved
anteriorly (flexed). Persists in the thoracic and sacral regions of the spine.
 Secondary There are two, which develop as an individual learns to hold head erect
(cervical curvature) and assumes erect posture (lumbar curvature). Concaved
posteriorly (extension). Persists in the cervical and lumbar regions of the spine.
 Abnormal curvatures:
 kyphosis: "dowager's hunch", exaggerated thoracic curvature
 lordosis: "swayback", exaggerated lumbar curvature
 scoliosis: lateral distortion - rib/vertebrae angle > 30, then brace
2. Features of Typical Vertebrae:
 body: chunky anterior portion (support) - compact bone surrounding spongy bone;
gives strength to the vertebral column and supports body weight.
 vertebral pedicles: rounded bars forming anterior sides of vertebral arch (protection),
have notches that join to form the intervertebral foramen through which the spinal
nerves exit the vertebral canal.
 laminas: flat, thin plates forming roof of vertebral arch (protection)
 vertebral arch: formed by the right and left pedicles and laminae
 vertebral foramen: space for spinal cord; collective foramen form vertebral canal
 spinous process: projects posteriorly from vertebral arch at the junction of the
laminae.
 provides attachment for various mm. (movement)
 transverse process: laterally directed at junction of lamina & pedicle
 provide attachment for various mm.
 articular processes: 2 superior and 2 inferior, also arise from junction of lamina and
pedicle. Superior of one vertebra articulate with inferior of next highest vertebra
forming zygapophysial (facet) joint, a plane type joint (limited movement).
 orientations of facet joints vary depending on region of spinal column
 cervical - transverse plane
 thoracic - coronal plane
 lumbar - saggital plane
 vertebral notches: superior of one vertebra joins inferior of next highest vertebra to
form intervertebral foramen thru which exit the spinal nerves
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley
3. Features of Regional and Individual Vertebrae:

Cervical Vertebrae: 7 total
 foramina transversaria: foramen within the transverse process that allow for
passage of the vertebral artery and vein with the exception of C7 thru which only
the vertebral vein passes.
 bifid spinous process: found in C3 through C6
 anterior and posterior tubercles - located on transverse processes; anterior
tubercle of C6 is called the carotid tubercle because the common carotid arteries
may be compressed against them to control bleeding from the vessel.
 uncinate processes- superior, lateral elevated margins of the bodies; prevents
posterior linear translocation of vertebral bodies and limits lateral flexion.
 C1, C2 and C7 are atypical:
 Atlas (C1) - ring shaped bone, does not have a body or spinous process.
They are replaced by anterior and posterior tubercles,
respectively.
- kidney shaped concaved superior articular surfaces for
articulation with occipital condyles.
- enlarged vertebral foramen to accommodate dens and
brainstem
- large superior & inferior articular processes for
atlanto-occipital and atlantoaxial joints
 Axis (C2) - dens/odontoid process, the pivot around which C1 rotates.
 Vertebra prominens (C7) - larger spinous process is first easily palpated of
vertebrae, reduced foramina transversaria carry
only vertebral vein.

Thoracic Vertebrae: 12 total
 costal facets for articulation with ribs  articulating facets on body and transverse
processes for head and tubercle of ribs, respectively.
 heart shaped vertebral body (when viewed from above).
 inferiorly directed spinous process overlaps arch of next lowest
 vertebral foramen is circular and smaller than those of cervical and lumbar
vertebrae.
 greatest amount of rotation of the spine is permitted here.
 vertebra (less pronounced in lower thoracic region)

Lumbar Vertebrae: 5 total
 heavy chunky bodies for support and kidney bean shaped (when viewed from
above).
 greatly reduces rotational movements in lumbar spine
 spinous processes are nearly rectangular
 posterior surface of base of transverse process has accessory process for
attachment of intertransversarii muscles
 posterior surface of superior articular process has mammillary process for
attachment of multifidis and intertransversarii muscles
 L5/S1 facet is in coronal plane
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley

L5 is significantly taller anteriorly and is largely responsible for lumbosacral
angle.

Sacrum: 5 fused vertebrae
 sturdy triangular bone wedges between pelvic bones to transmit weight from
vertebral column to lower limb.
 forms roof and posterosuperior wall of posterior half of pelvic cavity.
 anterior edge of the body is the sacral promontory
 lateral surface is auricular surface, for synovial sacroiliac joint
 auricular surfaces form slightly movable joint with iliac of pelvis
 fusion has resulted in:
1. spinous processes  median sacral crest
2. articular processes  intermediate sacral crests
3. transverse processes  two lateral sacral crests
4. intervertebral foramina  4 pair of sacral foramina
i. pelvic (for ventral primary rami)
ii. dorsal (for dorsal primary rami)
5. vertebral foramina  sacral canal with cauda equina
6. incomplete fusion of lowest laminas  sacral hiatus

Coccyx: 4 fused rudimentary coccygeal vertebrae (number can vary)
JOINTS OF VERTEBRAL COLUMN:
1. Intervertebral joints: symphysis type between vertebral bodies designed for weightbearing and strength.
 articulating surface of adjacent vertebral bodies are connected by
fibrocartilaginous disc (IV discs) and ligaments. Provide strong attachments
between the vertebral bodies. Each disc consists of:
 anulus fibrosis – form circumference of IV discs, fibers run obliquely from
disc to articular surface of vertebral body.
 nucleus pulposus – core of IV discs. Are responsible for much of the
flexibility and resilience of the IV discs and vertebral column. Serve as a
shock absorber.
 intervertebral joints, collectively, are stabilized by:
 anterior longitudinal ligament – connects anterior side of bodies from the
pelvic surface of the sacrum to the occipital bone. It is the only ligament that
prevents hyperextension
 posterior longitudinal ligament – located on the floor of vertebral canal.
Narrow band attached primarily to the IV discs. Superiorly becomes the
tectorial membrane, attaching to occipital bone
2. Zygapophysial Joints: Synovial, plane gliding joints (also referred to as facet joints).
 Between superior and inferior articular processes of adjacent vertebrae. Permit
gliding between the vertebrae. Enclosed in capsular ligaments.
 Accessory ligaments unite the laminae, transverse processes, and spinous
processes and help to stabilize the joints these include:
 supraspinous ligaments – connects the apices of the spinous process form
C7 to sacrum. Merges superiorly with nuchal ligament.
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley
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interspinous ligaments – connect adjoining spinous processes, attaching
rom the root to the apex of each process.
ligamenta flava – yellow ligaments, extend vertically connecting lamina.
Form part of posterior wall of the vertebral canal.
nuchal ligament – Also referred to as ligamentum nuchae (nuchae means
nape of neck). A broad, strong median ligament of the posterior neck.
Extends from external occipital protuberance and posterior border of foramen
magnum to spinous processes of cervical vertebrae. Provides sight of
attachment for some muscles (eg. trapezius)
3. Craniovertebral Joints: Synovial joints with no IV discs. Give a wider range of
movement
 atlanto-occipital joint : synovial hinge joint between occipital condyles and
superior articular processes of atlas, stabilized by three ligaments:
1. anterior atlanto-occipital membrane - continuation of anterior
longitudinal ligament
2. posterior atlanto-occipital membrane - from arch of atlas to
posterior margin of foramen magnum
3. tectorial membrane or membrana tectoria - continuation of
posterior longitudinal ligament into internal periosteum of occipital
bone

atlantoaxial joint : 3 articulations, synovial pivoting joint between dens of
axis and interior anterior surface of atlas, stabilized by:
1. cruciform ligament - consisting of transverse, superior and inferior
fibrous bands. Attaches atlas to foramen magnum, provides "socket"
for dens
2. apical ligament – extends from the tip of the dens to the anterior
margin of foramen magnum
3. alar ligaments – extends from the sides of the dens to the lateral
margins of the foramen magnum. Prevents excessive rotation.
provide attachment from dens to foramen magnum and secure dens
within its "socket"
CLINICAL TERMS:
1. spondylolysis: degenerative condition in which there is defect in the vertebral arch
resulting in a fracture usually between superior and inferior articular processes (pars
inarticularis)that separates the vertebral arch from the body.
2. spondylolisthesis: can result from spondylolysis, when the fracture results in
anterior displacement of the body of the vertebrae.
3. spondylosis: bony arthritic growth of vertebral bodies
LECTURE 3 - SUBOCCIPITAL REGION
SURFACE ANATOMY:
1. spinous process of C2: palpated inferior to external occipital protuberance
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley
2. transverse processes of CI: palpated deeply behind mastoid processes
3. Borders:
 from inferior nuchal line of occipital bone to spinous process of axis to transverse
process of atlas
 roof is the deep surface of semispinalis capitis m.
 floor is the posterior atlanto-occipital membrane
 Bounded by rectus capitis posterior major, superior and inferior oblique muscles
BONY FEATURES:
atlas, axis and occipital bone
MUSCLES:
 Muscles superficial to this region are trapezius, levator scapulae, splenius and
semispinalis capitis (from superficial to deep)
 All of the muscles of the suboccipital region are innervated by the posterior primary
rami of C1 (aka suboccipital nerve).
* indicates muscles which make up the boundaries of the triangle
1. rectus capitis posterior minor:
 attachments: below medial end of inferior nuchal line to posterior tubercle of atlas
deep to rectus capitis posterior major and outside of triangle
 innervation: suboccipital (C1)
 actions: stabilizes atlanto-occipital joint
2. rectus capitis posterior major*:
 attachments: below inferior nuchal line, lateral to rectus capitis posterior minor to
spine of axis
 innervation: suboccipital (C1)
 actions: extends head, rotates atlas and head to same side
3. obliquus capitis superior*:
 attachments: transverse process of atlas to inferior nuchal line, lateral to rectus
capitis posterior major
 innervation: suboccipital (C1)
 actions: extends head
4. obliquus capitis inferior*:
 attachments: transverse process of atlas to inferior nuchal line, lateral to rectus
capitis posterior major
 innervation: suboccipital (C1)
 actions: extends head
NERVES:
1. Suboccipital nerve: posterior primary rami of C1.
 This nerve is motor only and usually has no sensory roots, sensory to this region
is supplied by posterior primary rami of C2 (aka greater occipital nerve).
 Passes superior to the posterior arch of C1 and inferior to the vertebral artery to
emerge from center of suboccipital triangle.
2. Greater occipital nerve: post. primary ramus C2.
 Emerges inferior to oliquus capitis inferior muscles, passes medially to pierce
semispinalis capitis muscles; it then passes superolaterally to posterior scalp.
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley
 Provides sensory to posterior neck and scalp.
VESSELS:
1. Occipital artery: branch of external carotid artery.
 Enters region laterally from beneath the mastoid process, passes across
superolateral margin en route to posterior scalp.
2. Vertebral artery: branch of subclavian a.
 Ascends in the neck via transverse foramina of cervical vertebrae 1 – 6 and
passes over posterior arch of atlas to enter foramen magnum of skull
 lies deep to suboccipital muscles
 after entering foramen magnum, each vertebral a. joins the other to form the
basilar artery.
3. Basilar artery: forms the vertebrobasilar system, an important circulatory supplier of
the cerebrum
 obstruction can cause dizziness
LECTURE 4 - SCAPULAR AND DELTOID REGION
SURFACE ANATOMY:
1.
2.
3.
2.
posterior axillary fold: skin and latissimus dorsi and teres major
spine of scapula: root at medial end is opposite tip of T3 spinous process
inferior angle of scapula: opposite tip of T7 spinous process, over rib 7
triangle of auscultation: a relative thinning of the musculature of the back which allows
respiratory sounds to be heard more clearly. It is located medially to the inferior angle of
scapula. Created by gap between latissimus dorsi, rhomboid major, lateral border of
trapezius.
IMPORTANT MUSCULAR ATTACHMENTS:
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pectoral girdle to axial skeleton: levator scapulae, rhomboids, trapezius, (serratus
anterior, pectoralis minor, subclavius covered with upper extremity)
humerus to pectoral girdle: deltoid, supraspinatus, infraspinatus, teres major and
minor, subscapularis, (triceps and biceps, coracobrachialis
covered with upper
extremity)
humerus to axial skeleton: latissimus dorsi, (pectoralis major covered with upper
extremity)
1. Humerus:
 head: articulates with the shallow glenoid fossa of scapula in the ball-and-socket
glenohumeral joint
 anatomical neck: ligamentous attachment of shoulder joint, site of the epiphyseal
plate
 surgical neck: site of fractures which may involve the axillary n. and post.
humeral circumflex a. in quadrangular space
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley
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greater and lesser tubercles: next to anatomical neck; attachment site for
rotator cuff mm.(SIT and SS)
 greater creates the round countour of the shoulder; Loss of the contour is
sign of dislocated shoulder joint.
intertubercular sulcus (bicipital groove for tendon of long head of biceps)
 pectoralis major attaches to lateral edge
 latissimus dorsi attaches to floor
 teres major attaches to medial edge
deltoid tuberosity: insertion for deltoid m.
spiral groove: sulcus for radial n. and profunda brachii a.; between lateral and
medial heads of triceps on back of humerus
2. Scapula: mobile bone encased in muscle
 vertebral (medial) border: attachment for rhomboids, levator scapulae, serratus
anterior; runs from rib 2-7, used as imaging landmark
 inferior angle: teres major attachment
 axillary (lateral) border: attachment for teres major, teres minor and long head
of triceps (infraglenoid tubercle)
 spine: deltoid and trapezius attach; bends laterally to form acromion
 acromion: deltoid and trapezius attach; acromioclavicular joint
 coracoid process: (corax = crow); palpable 1" below clavicle; pectoralis minor,
coracobrachialis, short head of biceps brachii attach; coracoacromial and
coracoclavicular ligaments stabilize acromioclavicular joint
 glenoid fossa: forms ball-and-socket joint with head of humerus; features
supraglenoid and infraglenoid tubercles (for attachment of long heads of biceps
and triceps, respectively); faces ant. and lat. so that humerus looks like it is in
medial rotation
 supraspinous fossa: supraspinatus attaches
 Infraspinous fossa: infraspinatus and teres minor attach
 subscapular fossa: subscapularis attaches
 greater scapular notch (spinoglenoid notch): deep to acromion; provides
passage for suprascapular n. and a. to infraspinous fossa

suprascapular notch: scapular ligament closes superior border; suprascapular
n. (under) and suprascapular a. (above) ligament
3. Clavicle: acromial extremity: attaches deltoid, trapezius, pectoralis major, subclavius,
and sternocleidomastoid; acromioclavicular joint; first bone of body to ossify; most
frequently fractured bone in body.
MUSCLES:
Review trapezius (spinal accessory n.), rhomboids and levator scapulae (dorsal scapular
n. C 4-5), latissimus dorsi (thoracodorsal n. C 6 - 8)
1. Deltoid (delta = triangle):
 attachments: clavicle, scapular spine and acromion to deltoid tuberosity
innervation: axillary n. (C5-6) from post. cord of BP
 actions: most important function: abduction of arm w/supraspinatus;
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley

 anterior part flexion and medial rotation of humerus;
 middle partmajor abductor of humerus;
 posterior partextension and lateral rotation of humerus
innervation: axillary n. (C5-6) from post. cord of BP
ROTATOR CUFF MUSCLES: supraspinatus, infraspinatus, teres minor, subscapularis
(SITSS). Dynamic muscle, which means not only do they move the humerus but they
stabilize the glenohumeral joint.
 secure humerus at shoulder
 responsible for the strength and stability of the glenohumeral joint
 tendons form rotator cuff
2. Supraspinatus:
 attachments: supraspinous fossa to greater tubercle of humerus
 actions: abducts humerus
 innervation): suprascapular n. (C4-6) from upper trunk of BP
3. Infraspinatus:
 attachments: from infraspinous fossa to greater tubercle of humerus
 actions: laterally rotates humerus
 innervation: suprascapular n. (C4-6) from upper trunk of BP
4. Teres Minor:
 attachments: axillary border of scapula to greater tubercle
 innervation: axillary n. (C5-6) from post. cord of BP
 actions: laterally rotates humerus
5. Subscapularis:
 attachments: subscapular fossa to lesser tubercle of humerus
 innervation: upper and lower subscapular nn. (C5-7) post. cord BP
 actions: adducts and medially rotates humerus
Other muscle:
6. Teres Major:
 attachments: axillary border of scapula to medial edge of intertubercular sulcus
 innervation: lower subscapular n. (C5 - 7) from posterior cord BP
 actions: secures humerus at shoulder; adducts and medially rotates humerus
ARTERIES:
 Arteries of scapular and deltoid region contribute to arterial anastomosis of posterior
shoulder:
1. Transverse cervical artery: branch of thyrocervical trunk of subclavian a.
2. Suprascapular artery: branch of thyrocervical trunk crosses over suprascapular
ligament and accompanies suprascapular n. through spinoglenoid notch; supplies
posterior mm. of rotator cuff
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley
3. Dorsal scapular artery: frequently a deep branch of transverse cervical a.; supplies
mm. of medial border of scapula
4. Circumflex scapular artery: branch of subscapular a. (from axillary a.); passes
around axillary border to supply teres major and minor mm.
 Other arteries:
5. Posterior circumflex humeral artery: branch of axillary a., passes behind surgical
neck of humerus, (quadrangular space) to supply deltoid and teres major mm.
6. Profunda Brachii artery (deep brachial a.): branch of brachial a.; passes deeply
within triangular interval, accompanied by radial n., following spiral groove on back of
humerus
NERVES:
1. Spinal accessory nerve (CN XI)- trapezius)
2. Dorsal scapular nerve C4-5 - rhomboids)
3. Suprascapular nerve: C4-6; from upper trunk of BP; passes posteriorly through
suprascapular and spinoglenoid notches; supplies supraspinatus and infraspinatus
4. Axillary nerve: C5-6; terminal branch of posterior cord BP, passes posteriorly
(quadrangular space) to supply deltoid and teres minor mm.
5. Radial nerve: C5 - T1; terminal branch of posterior cord BP, passes along back of
humerus, (triangular interval) along radial groove; nerve supply to posterior
compartments of upper limb
ANATOMICAL SPACES:

Triangular space: bounded by teres minor (medially), teres major (inferiorly) and long
head of triceps brachii (laterally); contains circumflex scapular a.

Quadrangular (quadrilateral) space: bounded by teres major (inferiorly), teres minor
(superiorly), long head of triceps brachii (medially) and medial aspect of surgical neck
of humerus (lateral); transmits posterior circumflex humeral a. and axillary n. to
posterior shoulder region

Triangular interval: bounded by lateral and long heads of triceps brachii (laterally and
medially, respectively) and teres major (superiorly); contains profunda brachii a. and
radial n.
JOINTS:
1. Glenohumeral: ball-and-socket joint between head of humerus and glenoid fossa of
scapula; more freely mobile than hip, but less stable (easily dislocated)

glenoid labrum: ring of cartilage which deepens fossa, blends with
tendon of long head of biceps superiorly

supra- and infraglenoid tubercles: attachments for long heads of biceps
and triceps, respectively; tendon for long head of biceps passes thru the
joint outside of the synovial membrane
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley

capsule is open for entrance of tendon of long head of biceps and under
coracoid process

subscapular bursa - between subscapularis tendon and neck of scapula
communicates with the shoulder joint; weakest inferiorly

subacromial/subdeltoid bursa between deltoid and supraspinatus
tendon - no communication with shoulder joint

glenohumeral ligaments: anterior reinforcement of joint capsule

transverse humeral ligament - between tubercles, straps tendon

rotator cuff: SIT SS mm. ("dynamic ligaments")

coracoacromial arch: acromion, coracoid process and coracoacromial
lig., opposes upward displacement of humeral head, supraspinatus
passes under it, with overlying subacromial/deltoid bursa
 anterior displacement - extension and lateral rotation, rips capsule
 inferior displacement - during abduction
2. Acromioclavicular Joint: weak plane or gliding joint between acromion of scapula
and lateral extremity of clavicle; dislocates frequently
 coracoclavicular ligament (strongest - trapezoid lateral, conoid medial)
 acromioclavicular ligaments
 articular cartilage intrudes from above into joint cavity
 lateral sliding of clavicle over acromion = "shoulder separation",
 shoulder falls away from the clavicle
3. Sternoclavicular Joint: saddle-type joint between medial extremity of clavicle and
manubrium of sternum - manubrium side is like a socket; only bony connection of
pectoral girdle with axial skeleton
 fibrocartilagenous disk inside joint attaching to sternoclavicular lig., prevents
medial displacement of clavicle
 stabilized by sternoclavicular, interclavicular and costoclavicular ligaments
 supported by subclavius muscle; rarely dislocates
CLINICAL TERMS:
Shoulder impingement: pressure on rotator cuff tendons passing under the acromion and
coracoacromial arch.
LECTURE 5 - ANTERIOR/LATERAL LEG AND DORSUM OF FOOT
SURFACE ANATOMY:
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Subcutanteous platysma muscle
Sternocleidomastoid as it goes from the mastoid process to the sternum and clavicle
(2 heads).
 key muscular landmark in the neck, visibly divides each side of the neck into
the anterior and posterior cervical triangles.
 lies between external and internal jugular
 protects carotid sheath
Jugular notch of the manubrium between heads of sternocleidomastoid muscle
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley
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(SCM)
Suprasternal space with access to inferior end of the inferior jugular vein between the
sternal and clavicular heads of SCM
Subclavian triangle between the trapezius & SCM over the clavicle allows pulse
palaption of the subclavian artery
Palpable Features:
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hyoid bone
transverse processes of the atlas
inferior border of the mandible
vertebra prominens  spinous process of C7
laryngeal prominence at level of C4
cricoid cartilage at level of C6
GENERAL ORGANIZATION:
The neck is organized as tubes within a tube:
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superficial fascia: contains platysma muscle (supplied by facial nerve)
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deep fascia:
 investing layer: trapezius and SCM
 prevertebral fascia: cervical vertebral column including spinal cord, and true
back muscles
 pretracheal fascia: infrahyoid muscles and cervical visera including:
 digestive (esophagus)
 respiratory (larynx, trachea)
 endocrine (thyroid gland)
 carotid sheath: arteries and veins serving the head:
 common cartotid a.
 internal jugular v.
 vagus n.
BOUNDARIES:
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anterior boundary  SCM
posterior boundary  trapezius
inferior boundary  clavicle
 Subdivisions:
 “Carefree” and “careful” zones defined by spinal accessory nerve.
 carefree zone is superior to spinal accessory. “three go up” these are
lesser occipital n., great auricular n., and transverse cervical n.
 careful zone is inferior to spinal accessory. “three go down” these are
the supraclavicular nerves: medial, intermediate, lateral nn. This is
referred to as the careful zone because deep within this zone is the
brachial plexus and subclavian artery and vein.
 subclavian triangle (omoclavicular) created within posterior cervical triangle
by inferior belly of omohyoid.
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley
BONY FEATURES:
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Temporal bone: mastoid process (SCM attachment)
Sternum: anterior surface of manubrium (SCM attachment)
Clavicle: medial third of clavicle (SCM attachment)
Rib 1: scalene tubercle (anterior scalene attachment) and superior surface (middle
scalene attachment)
Cervical vertebrae: anterior and posterior tubercle of transverse processes (anterior
and middle scalenes attachments, respectively).
MUSCLES:
1. Platysma:
 attachments: inferior border of mandible skin and subcutaneous tissue of lower
face to fascia covering superior parts of pec major and deltoids
 innervation: cervical branch of facial n.
 actions: draws cornes of mouth inferiorly and widens it as in expressions of
sadness and fright; Draws skin of neck superiorly when teeth are clenched.
2. Omohyoid:
 attachments: superior border of scapula near suprascapular notch to hyoid
bone.
 innervation: ansa cervicalis (C1-C3)
 actions: depresses hyoid bone.
3. Sternocleidomastoid:
 attachments: lateral surface of mastoid process to anterior surface of
manubrium (sternal head) and superior surface of medial third of clavicle
(clavicular head)
 innervation: cranial nerve XI (spinal accessory) and anterior primary rami of C2
and C3 (proprioception)
 actions: ipsilateral flexion contralateral rotation, bilateral contraction causes: 1)
extends neck at atlanto-occipital joints; 2) flexes cervical vertebrae; 3) thrusts
chin out. Assist in respiration.
 congenital fibrosus of SCM on one side causes a condition called
torticollis AKA wryneck
4. Anterior scalene: (scalenus anterior)
 attachments: anterior tubercles of transverse process of C3-C6 to scalene
tubercle of rib1.
 innervation: anterior primary rami of cervical nn.
 actions: flex head
5. Middle scalene: (scalenus medius)
 attachments: posterior tubercles of transverse process of C3-C7 to superior
surface of rib1 (posterior to groove for subclavian a.)
 innervation: anterior primary rami of cervical nn.
 actions: flexes neck laterally, assist in respiration by elevating rib 1 during forced
inspiration.
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley
6. Posterior scalene: (scalenus posterior)
 attachments: posterior tubercles of transverse process of C3-C7 external
surface of rib 2.
 innervation: anterior primary rami of cervical nn.
 actions: flexes neck laterally, assist in respiration by elevating rib 2 during forced
inspiration.
7. Subclavius: described with pectoral region
8. Splenius capitis and levator scapulae: are located superior and posterior to the
middle scalene.
NERVES:
Superficial:
1. Lesser occipital n.: C2; follows posterior border of sternocleidomastoid m. to supply
sensory to skin posterior to ear.
2. Great auricular n.: C2 and C3; travels vertically on surface of SCM to supply
sensory to skin around external ear.
3. Transverse cervical n.: C2 and C3; travels horizontally on surface of SCM to supply
sensory to skin covering anterior cervical triangle.
Deep:
4. Spinal accessory n.: supplies trapezius and SCM, has spinal roots from C1-C5,
cranial roots supply larynx and pharynx (along with vagus).
5. Phrenic n.: C3-C5; crosses anterior scalene, provides motor to diaphragm
6. Brachial plexus: C5-T1; roots and trunks emerge between and anterior and middle
scalene. Superior, middle and inferior trunks located superior to the clavicle.
7. Suprascapular n.: C4-C6; from upper trunk of brachial plexus, innervates
supraspinatus and infraspinatus.
8. Dorsal scapular n.: C4-C5; from C5 root receives contribution from C4, innervates
rhomboids and levator scapulae.
VESSELS:
1. Subclavian a.: passes posterior to scalenus anterior m. to lateral border of rib 1 at
which point it becomes the axillary a. Is found deep to the clavicle in the subclavian
triangle. Important branches vertebral a., dorsal scapular a.*, and thyrocervical trunk.
* the dorsal scapular a. is sometimes a branch of the thyrocervical trunk
2. thyrocervical trunk: 3 branches: suprascapular a., transverse cervical a. and dorsal
scapular a.
3. suprascapular a.: travels posteriorly passing deep to the clavicle from thyrocervical
trunk to supply dorsal scapular mm.
4. transverse cervical a: travels posteriorly across anterior scalene superior to the
clavicle and deep to omohyoid; supplies trapezius.
5. dorsal scapular a.: branches either directly from subclavian or from thyrocervical
trunk; supplies rhomboids and levator scapulae mm.
6. subclavian v.: passes superficial to scalenus anterior m.
CLINICAL TERMS:
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley
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Thoracic outlet syndrome - subclavian artery and vein, and T1 spinal nerve pass out of
the thorax to enter the posterior cervical triangle, any pathology (tumor) or anomaly
(cervical rib) can cause pressure and resulting symptoms on the artery, vein, and/or
nerve distribution in the upper extremity. Symptoms are pain, decoloration of the hands,
one hand colder than the other hand, weakness of the hand and arm muscles, and
tingling are commonly present.
EMBRYOLOGY OF THE LIMB
1. migration of epiblast cells forms a midline notochord and lateral paraxial,
intermediate, and lateral plate mesoderm
2. as neural tube forms, embryo folds ventrally to form the gut tube
3. paraxial mesoderm organizes into segmental blocks of cells called somites,
somitomeres in the head region, that differentiate into skull, vertebrae, muscles,
dermis
4. intermediate mesoderm contributes to the urogenital system
5. lateral plate mesoderm splits into peripheral somatic (parietal) layer that lines the
ectoderm and deeper splanchnic (visceral layer) that overlies gut tube
6. somites have ventromedial sclerotome (forming bone), dorsolateral and
dorsomedial myotome forming hypomeric and epimeric (paraspinal) muscles,
separated by dermatome that differentiates into dermis
7. limb development begins at 4th week
8. limb buds are outgrowths with a core of mesoderm from somatic layer of lateral
plate mesoderm, covered by ectoderm
9. ectoderm at the tip thickens to form apical ectodermal ridge, inducing
mesenchyme to condense as a progress zone to elongate it
10. girdles develop first, phalanges last
11. bones form from lateral plate mesoderm, muscles from migration of myotome of
somites
12. as limbs elongate they rotate - upper 90 degrees laterally, lower 90 degrees medially
13. as the somite differentiates, derivatives are supplied by the nerve that serves that
somite.
14. spinal nerves divide into dorsal primary ramus for epimere muculature, of that
segment, ventral primary ramus for hypomere muscles from that segment, the
dermatome is also supplied by the spinal nerve of that somite
These notes have been adapted from the notes of Dr. Ted Hart and Dr. Mary Hurley