Basic
Anatomy
Anatomy- is the science of the structure and function of the body.
Clinical Anatomy- is the study of the macroscopic structure and function of
the body as it relates to the practice of medicine and other health services.
Basic Anatomy- is the study of the minimal amount of anatomy consistent
with the understanding of the overall structure and function of the body.
Descriptive Anatomical
Terms
Terms Related to Position:
Median Sagittal Plane- vertical plane passing through the center of the
body.
- dividing it into equal right and left halves.
Paramedian- situated to one or the other side of the median plane and
parallel
Median- situated nearer to median plane.
Lateral- lies farther away from the median plane.
Coronal Plane- imaginary vertical planes at right angles to the median
plane.
Horizontal, or Transverse Planes
- these planes area at right angles to both the median and the coronal
planes
Anatomical term
Area of the body it relates to
Anterior/ventral
front surface of the body, or structure
Posterior/dorsal
back surface of the body, or structure
Deep
further from the surface
Superficial
near the surface
Internal
nearer the inside
External
nearer the outside
Lateral
away from the midline
Medial
towards the midline
Anatomical term
Area of the body it relates to
Superior/ cranial/ cephalad
situated above or towards the upper part
Inferior/ caudal
situated below or towards the lower part
Proximal
nearest to the point of reference
Distal
furthest away from the point of reference
Prone
lying face down in a horizontal position
Supine
lying face up in a horizontal position
Ipsilateral
same side of the body.
Contralateral
opposite sides of the body.
Anatomical term
Terms Related to Movement
Flexion
movement that takes place in a sagittal plane;
decreasing the angle.
Extension
straighten the joint, increasing the angle.
Lateral flexion
movement of the trunk in the coronal plane.
Abduction
movement away from the midline; coronal plane.
Adduction
movement towards the midline.
Rotation (Medial/Lateral)
movement around its long axis.
Anatomical term
Terms Related to Movement
Pronation of the forearm
palm of the hand faces posteriorly.
Supination of the forearm
palm of the hand faces anteriorly.
Circumduction
combination of flexion, extension, abduction, and adduction.
Protraction
move forward.
Retraction
move backward.
Inversion
movement of the foot so that the sole faces in a medial direction.
Eversion
movement of the foot so that the sole faces in a lateral direction.
Anterior Body Landmark:
TERM
DEFINITION
Abdominal
Anterior body trunk inferior to ribs
Acromial
point of shoulder
Antebrachial
foream
Antecubital
Anterior surface of elbow
Axillary
Armpit
Brachial
Arm
Buccal
Cheek area
Carpal
Wrist
Cervical
Neck region
Coxal
hip
Crural
leg
Anterior Body Landmark:
TERM
DEFINITION
deltoid
curve of shoulder formed by large deltoid muscle
digital
fingers, toes
femoral
thigh
fibular/peroneal
lateral part of the leg
frontal
forehead
inguinal
area where the thigh meets body trunk; groin
nasal
nose area
oral
mouth
orbital
eye area
Anterior Body Landmark:
TERM
DEFINITION
Patellar
Anterior knee
Pelvic
area overlying the pelvis anteriorly
Pubic
Genital region
Sternal
Breastbone area
Tarsal
Ankle region
Thoracic
Chest
Umbilical
navel
Posterior Body Landmark:
TERM
DEFINITION
Calcaneal
heel of foot
Cephalic
head
Femoral
thigh
Gluteal
buttock
Lumbar
area of back between the ribs and hips
Occipital
posterior surface of the head
Posterior Body Landmark:
TERM
DEFINITION
Olecranal
posterior surface of the elbow
Popliteal
posterior knee area
sacral
area between hips
scapular
shoulder blade region
sural
posterior surface of the leg; calf
vertebral
area of spine
Regional Terms:
•Axial region- includes the head, neck and trunk
•Appendicular region- consists of the upper and lower limbs
Basic Structures
Skin:
Epidermis- is a stratified epithelium whose cells become flattened as they
mature and rise to the surface.
- extremely thick on the palms of the hands and soles of the feet.
Dermis- composed of dense connective tissue containing many blood
vessels, lymphatic vessel, and nerves.
LAYERS OF THE EPIDERMIS:
1.
Stratum Corneum- shingle-like dead cells are filled with keratin.
2.
Stratum Lucidum- formed from dead cells and only occurs in thick portions of the
palms and soles of feet.
3.
Stratum Granulosum- contain live keratinocytes langerhans cells.
4.
Stratum Spinosum- spiny layer; also contain keratinocytes and langerhans.
5.
Stratum Basale (stratum germinativum)- contains melanocytes and merkel cells.
DERMIS:
20-30x thicker than the epidermis
has an extensive vascular supply especially the papillary layer
made up of collagen and elastic fibers
Resistant to deformation( provides a tensile strength and elasticity to
avoid deformation).
considered as the “true” skin
divides into the papillary layer and the reticular layer.
LAYERS OF THE DERMIS:
1.
Reticular Layer (Deep) > consists of dense connective tissue composed
of coarse collagen fibers and some elastic and reticular fibers; hair
follicles and muscles of facial expression are inserted here.
1.
Papillary Layer > usually thinner that anchors the dermis to the overlying
epidermis; accessory skin organs are supported and maintained by this
layer.
Appendages of the skin:
Nails
Hair follicles
Sebaceous glands
Sweat glands
CLINICAL NOTES:
Paronychia- infection occurring between the nail and the nail fold.
Boil- infection of the hair follicle and sebaceous gland.
Carbuncle- is a staphylococcal infection of the superficial fascia.
Burns- is a type of injury to skin, or other tissues, caused by heat, cold,
electricity, chemicals, friction, or radiation.
Fasciae:
2 TYPES:
1. Superficial fascia, or subcutaneous tissue
- mixture of loose areolar and adipose tissue that unites the dermis of the
skin to the underlying deep fascia.
2. Deep fascia
- is a membranous layer of connective tissue - in the limbs, if forms a
definite sheath around the muscles and other structures, holding them in place.
- forms restraining bands called retinacula in the region of joints.
Muscles:
3 types of muscle tissue:
1.
Skeletal muscle
2.
Smooth muscle
3.
Cardiac muscle
1. Skeletal Muscle:
voluntary muscles
produce the movements of the skeleton
it has 2 or more attachments
origin
insertion
belly
tendons
raphe, is an interdigitation of the tendinous ends of fibers of flat muscle.
Internal Structure of Skeletal Muscle:
Pennate muscles- whose fibers run obliquely to the line of pull (resemble
as feather)
Unipennate muscle- tendon lies along one side of the muscle and the
muscle fibers pass obliquely to it. (eg. Extensor digitorum longus)
Internal Structure of Skeletal Muscle:
Bipennate muscle- tendon lies in the center of the muscle and the
muscle fibers pass to it from two sides. (eg. Rectus femoris)
Multipennate muscle- may be arranged in series of bipennate muscles
lying alongside one another (acromial fibers of the deltoid) or may have
tendon lying within its center and the muscle fibers passing to it from all
sides, converging as they go (eg. TA)
Skeletal Muscle Action
Prime Mover- chief muscle or member of a chief group of muscles
responsible for a particular movement.
Antagonist- muscle that opposes the action of the prime mover.
Fixator- contracts isometrically to stabilized the origin of the prime mover so
that it act efficiently.
Synergist- prevent unwanted movements in an intermediate joint. (eg. Flexor
and extensor mm of the carpus contract to fix the wrist joint, and this allows
the long flexor and the extensor mm of the fingers to work efficiently.
2. Smooth Muscle
consists of long, spindle-shaped cells closely arranged in bundles or
sheets.
3. Cardiac Muscle
consists of striated muscle fibers that branch and unite with each other.
forms the myocardium of the heart
specialized cardiac muscle fibers form the conducting system of the heart
it is supplied by autonomic nerve fibers that terminate in the nodes of the
conducting system and in the myocardium.
THE
SKELETAL
SYSTEM
SKELETAL SYSTEM INCLUDES THE FOLLOWING:
Bones
Joints
Cartilage- provide flexible support
Ligaments- attach bone and hold them together.
Tendons
Skeleton- comes from the Greek word means “dried-up body.
Subdivisions:
• Axial skeleton- bones that form the longitudinal axis of the body.
• Appendicular skeleton- bones of the limbs and girdles
FUNCTIONS OF THE BONES
1.
Support- rigid strong framework well-suited
2.
Protection- protect internal organs
3.
Movement- muscle attach to bone
4.
Storage- for important minerals especially calcium, fatty tissue
5.
Hematopoiesis- blood cell formation
CLASSIFICATION OF BONE ACCORDING TO
STRUCTURE:
1.
Spongy bone- composed of needle-like pieces of bone with lots of open
spaces.
2.
Compact bone- form by tightly-packed bone tissues.
CLASSIFICATION OF BONE ACCORDING TO
SHAPE:
1.
Long bones- all bones of the limbs except patella, wrist and ankle;
mostly compact
2.
Short bones- generally cube-shaped; mostly spongy; wrist and ankle
• sesamoid bone
3.
Flat bones- thin, flattened and usually curved.
• have two layers of compact bone sandwiching a layer of spongy bone
• skull, ribs, and sternum
4.
Irregular bone- does not fit to above category.
• vertebrae, hip bones
Structure of Long bone:
• Epiphysis- ends of bone
• Diaphysis- body of bone/ shaft
• Articular cartilage- covering end of the bone/ epiphysis. It is made up of
hyaline that provides a smooth, slippery surface that decrease friction.
• Periosteum- a fibrous connective tissue covering of diaphysis
• Sharpey’s fiber- attaches the periosteum to underlying diaphysis
• Endosteum- thin membrane that secure periosteum to the underlying bone
• Epiphyseal plate/line- joins the epiphysis to diaphysis
• Medullary cavity- storage area for adipose tissue.
AXIAL
SKULL
• CRANIUM- composed of eight large flat bones except for 2 paired parietal
and temporal which is single.
• FACIAL BONES- 14 bones. 12 paired; only the mandible and vomer are
single.
CRANIUM
A.
Frontal bone
B.
Parietal bone- sagittal suture and coronal suture
C.
Temporal bone- squamous sutures
external acoustic meatus- canal lead to eardrum
styloid process- sharp, needlelike projection; attachment of neck mm
zygomatic process- thin bridge that joins cheek bone anteriorly
mastoid process- mastoid sinuses high risk spot of infections: mastoiditis
jugular foramen- junction of the occipital and temporal bones; passage of
jugular vein (largest vein of the brain).
C. Occipital bone- forms the floor and back wall of the
skull.
lambdoid suture- joins the parietal bones anteriorly.
foramen magnum- allows the spinal cord to connect
with the brain.
external occipital protuberance
Sphenoid bone- butterfly-shaped
Sella turcica/ turk saddle- small depression that form a snug
enclosure for the pituitary gland.
FACIAL BONES
• Maxillae/ maxillary bones- forms the upper jaw; keystone of the face.
• Palatine bones- ( hard palate; soft palate);failure to fuse medially results
in cleft palate
• Zygomatic bones- referred as cheekbone; also form a good-sized portion
of the lateral walls of the orbits or eye sockets.
• Lacrimal bones- fingernail-sized; groove serve as passageway for lacrima
(tear).
• Nasal bones- small rectangular bones forming the bridge of the nose.;
lower part is cartilage
• Vomer bone- (plow) which refers to bone shape; single bone in the
median line of the nasal cavity
• Inferior nasal conchae- thin, curved bones; filters the air that enters the
lungs.
• Mandible- lower jaw; largest and strongest bone of the face.
• body- forms the chin
HYOID BONE
• Only bone of the body that does not articulate directly with any other
bone.
• suspended in the midneck 2cm (1inch) above the larynx.
• horseshoe-shaped with body and two pairs of horns/ cornua
• serve as movable base for the tongue and attachment point of neck
muscles.
VERTEBRAL COLUMN (SPINE)
• 26 irregular bones (7 cervical; 12 thoracic; 5 lumbar; 1 sacrum; 1 coccyx)
• before birth (33); 9 of them fused to form the two composite bones: sacrum;
and coccyx
• intervertebral discs- flexible fibrocartilage that separate individual vertebrae
COMMON FEATURES OF THE VERTEBRAE:
• Body/ centrum: disclike, weight-bearing part facing anteriorly in the vertebral column
• Vertebral arch: form from the joining of all posterior extensions ( laminae and pedicles)
• Vertebral foramen: canal through which spinal cord passes
• Transverse processes: two lateral projections from the vertebral arch.
• Spinous process:
single projection arising from posterior aspect of vertebral arch.
(fused laminae)
• Superior & inferior articular processes:
paired projections lateral to the vertebral
foramen; allows vertebra to form joints with adjacent vertebrae
CERVICAL:
●
C1-C7; c1 and c2: atypical
●
C1/ ATLAS; no body;
■ Atlanto-occipital joint (atlas and occiput)- “yes” joint
●
C2/ AXIS; dens which act as pivot point
■ Atlantoaxial joint (atlas and axis) - “no” joint; allows to rotate the head.
●
C3-c7: typical ; smallest, lightest, most often, the spinous processes are short, and
divided into two branches.
THORACIC:
•
T1-T12: typical; larger than the cervical
•
the only vertebrae to articulate with the ribs
•
•
heart shaped and has two costal facets to receive the head of the ribs.
spinous processes are long and hooks sharply downward (causing it to
look like a giraffe’s head)
LUMBAR:
•
L1-L5: massive, blocklike bodies.
•
short, hatchet-shaped spinous processes (look like a moose head)
•
most of the stress on the vertebral column occurs in these regions.
SACRUM:
• Formed by fusion of 5 vertebrae.
• Superiorly it articulates with L5; and inferiorly connects with the coccyx.
COCCYX:
•
Formed from the fusion of three to five tiny, irregularly shaped vertebrae.
•
Human “tailbone” a remnant of the tail that other vertebrate animals.
THORACIC CAGE:
• STERNUM
• RIBS
• THORACIC VERTEBRAE
STERNUM:
• AKA: breast bones/ shield bone
• Typical flat bone and result of the fusion of three bones:
manubrium, body, xiphoid
process.
• It is attached to the first seven pairs of ribs.
LANDMARKS:
1.
Jugular notch: T3; palpated easily
2.
Sternal angle: manubrium and body meet; handy reference point for counting ribs to
locate the 2nd intercostal space for listening heart valves.
3.
Xiphisternal joint: sternal body and xiphoid process fuse; T9
RIBS:
•
TRUE RIBS- 7th pairs; attach directly to the sternum by costal cartilages.
•
FALSE RIBS- next 5 pairs; attach indirectly to the sternum or are not
attached to the sternum at all.
•
FLOATING RIBS: lack the sternal attachment
At the intercostal spaces, muscle were attached and aid in breathing.
APPENDICULAR
SKELETON
BONES OF THE SHOULDER GIRDLE:
• Aka: pectoral girdle
• Clavicle/ collar bone/strut bone: slender, double curved bone.
• it acts as brace to hold the arm away from the top of the thorax and prevent
shoulder dislocation.
• Scapulae/ shoulder blades: triangular and commonly called “wings”
• acromion- enlarge end of the spine; connects with the clavicle laterally at the
acromioclavicular joint
• coracoid - beaklike
• glenoid cavity- shallow socket that that receives the head of the humerus
BORDERS OF THE SCAPULA:
• SUPERIOR
• MEDIAL
• LATERAL
BONES OF THE UPPER LIMBS:
1. HUMERUS- arm bone; which is typical long bone
• anatomical neck
• intertubercular sulcus: greater and lesser tubercles; site of muscle
attachments
• surgical neck: distal to the tubercles
• distal tuberosity: larges fleshy deltoid muscle attaches.
• radial groove: radial nerve
• trochlea: (medial)distal end, looks somewhat like a spool
• capitulum: (lateral) ball-like; with the trochlea articulates with the FA
• coronoid fossa: above trochlea, anteriorly
• olecranon fossa: above trochlea, posteriorly
• med. & lat. Epicondyles: allow ulna to move freely when elbow is bent &
extended.
2. FOREARM- radius and ulna
RADIUS: lateral, thumb side
• distal end crosses over and ends up medial to the ulna when hand faces
backward.
• styloid process: distal end; connected to ulna via interosseous membrane.;
radioulnar joints ( proximal and distal of ulna and radius articulates)
• disc-shaped head of the radius forms a joint with the capitulum
• radial tuberosity: where the tendon of the biceps muscles attaches.
ULNA: medial bone
•
coronoid process
•
coronoid process
•
posterior olecranon process- separated by the trochlear notch.
3.
•
HAND: consist of the carpals, metacarpals, and the phalanges
carpals/ wrist: scaphoid, lunate, triquetrum, pisiform
trapezium, trapezoid, capitate, hamate
•
metacarpals: consist of the hand; knuckles (head of the metacarpals
•
phalanges: fingers
BONES OF THE PELVIC GIRDLE:
• PELVIC GIRDLE- formed by two coxal bones/ ossa coxae, commonly called: hip
bone
• pelvic girdle: 2 coxal bones; bony pelvis: 2 coxal bones, sacrum and coccyx
• Hip bone: formed by fusion of three bones: ilium, ischium, and pubis.
1. Ilium: connects posteriorly with the sacrum at the sacroiliac joint
• is a large, flaring bone that form most of the hip bone.
2. Ischium: sit-down bone, since it forms the most inferior part of the coxal
bone.
• ischial tuberosity: a roughened area that receives body weight when
you are sitting.
• Ischial spine: anatomical landmark, particularly pregnant since it
narrows the outlet of the pelvis through which baby must pass during
the birth process.
3. Pubis/ pubic bone: most anterior part of the coxal bone.
• obturator foramen: an opening that allows blood vessels and nerve to
pass into the anterior thigh.
• pubic symphysis: cartilaginous joint where 2 pubic bone fuse.
Acetabulum: “ vinegar cup”; receives the head of the thigh bone.
BONES OF THE LOWER LIMBS:
• FEMUR/ thigh bone: only bone in the thigh; heaviest, strongest bone in the body.
• greater/lesser
trochanters:
separated
by
intertrochanteric
line
anteriorly;
intertrochanteric crest posteriorly
• Fovea capitis: depression, foramen where blood vessels pass through.
• TIBIA/ shinbone: larger and more medial
• patellar ligament/ kneecap: roughened ligament attaches to tibial tuberosity.
• medial malleolus- forms the inner bulge of the ankle
• Fibula/splint bone: thin and sticklike
• lateral malleolus- forms the outer part of the ankle.
•
FOOT: composed of the tarsals, metatarsals, and phalanges
•
supports the body weight and serves as lever that allows us to propel
our bodies forward when we walk and run.
•
TARSUS:
forming the post.half of the foot with seven tarsal bones
(calcaneus/heel bone, talus/ankle, lateral cuneiform, medial cuneiform,
intermediate cuneiform, navicular, cuboid)
•
METATARSALS: 5
•
PHALANGES: 14
Joints
site where two or more bones come together, whether or not movement
occurs between them.
Classification of Joints According to Tissues:
Fibrous joints
Cartilaginous joints
Synovial joints
Fibrous joints
very little movement
Cartilaginous joints
2 types
1.
Primary cartilaginous joints
bones are united by a plate or a bar of hyaline cartilage.
union bet. epiphysis & diaphysis of a growing bone
no movement is possible
2. Secondary cartilaginous joint
bones are united by a plate of fibrocartilage and the articular surfaces of the bones
are covered by a thin layer of hyaline cartilage.
only a small amount of movement.
Synovial joints
the articular surfaces of the bones are covered by a thin layer of hyaline
cartilage separated by a joint cavity.
provides greater degree of movement.
lubricated by a viscous fluid called synovial fluid
Fatty pads- found in some synovial joints lying between the synovial
membrane and the fibrous capsule or bone.
Types of Synovial joints
1. Plane joints
Apposed articular surfaces are flat or almost flat.
Permits the bones to slide on one another
Eg. SC and AC joints
Eg. 2nd-5th CMC; midcarpal
Types of Synovial joints
2. Hinge joints/ uniaxial
resembles the hinge on a door, so that flexion and extension movements are
possible.
eg. Elbow, knee, and ankle joints
3. Pivot joints
central bony pivot is surrounded by a bony-ligamentous ring
movement: ONLY rotation
eg. Atlantoaxial and superior radioulnar joints
Types of Synovial joints
4. Condyloid joints
has two distinct convex surfaces that articulate with two concave surfaces.
movements: flexion, extension, abd. and add together WITH A SMALL AMOUNT of
rotation
eg. MCP or knuckles joints
5. Ellipsoid joints
Elliptical convex articular surface fits into an elliptical concave articular surface.
movements: flexion, extension, abd. , add WITHOUT rotation.
Eg. Wrist joint
Types of Synovial joints
6. Saddle joints
surfaces are reciprocally concave-convex and resemble a saddle on a horse’s back.
movements: flexion, extension, abd., add. and rotation
eg. CMC joint of the thumb
7. Ball and socket joints
ball shaped head and sockelike concavity of another.
movements: flexion, extension, abd., add., lat. and med. rotation and circumduction.
Eg. Shoulder and hip
Stability of the Joints
articular surfaces
ligaments
muscle tone
Ligaments:
is a cord or band of connective tissue uniting two structures.
2 types of ligaments:
1.
Type I- composed of dense bundles of collagen fibers and are unstretchable under
normal conditions.
- (eg. Iliofemoral lig. of hip and collateral lig.of elbow joint)
2.
Type II- composed largely of elastic tissues and can therefore regain its original
length after stretching.
- (eg. Ligamentum flavum of vertebral column and calcaneonavicular ligament of the
foot.)
Bursae:
is a lubricating device consisting of a closed fibrous sac lined with a
delicate smooth membrane.
wall are separated by a film of viscous fluid.
can be found wherever tendons rub against bones, lig.or other tendons.
eg.patellar bursa
Synovial Sheath:
is a tubular bursa that surrounds a tendon.
reduce friction between the tendon and surrounding structures.
mesotendon enables blood vessels to enter the tendon along its course.
vincula; narrow threads of mesotendon
Mucous Membranes:
it is the lining of an organs or passages that communicate with the
surface of the body.
Serous Membranes:
line the cavities of the trunk and are reflected onto the mobile viscera.
1.
Parietal layer- serous membrane lining the wall of the cavity.
supplied by spinal nerves
sensitive to all common sensations: touch and pain.
2.
Visceral layer- covers the viscera
supplied by autonomic nerves
insensitive to touch and temp. but VERY SENSITIVE TO STRETCH.
Surface Markings of Bones
Bone Marking
Example
Linear Elevation
Line
Ridge
Superior nuchal line of the occipital bone
Medial and lateral supracondylar ridges of the humerus
The iliac crest of the hip bone
Crest
Rounded Elevation
Tubercle
Protuberance
Tuberosity
Malleolus
Trochanter
Pubic tubercle
External occipital protuberance
Greater and lesser tuberosities of the humerus
Med. malleolus of the tibia, lat. malleolus of the fibula
Greater and lesser trochanter of the femur
Sharp elevation
Spine or spinous process
Styloid process
Ischial spine, spine of vertebra
Styloid process of the temporal bone
Expanded ends for articulation
Head
Head of humerus, femur
Condyle
Medial and lateral condyles of femur
Epicondyle (prominence above condyle) Medial and lateral epicondyle of femur
Small flat area for articulation
Facet
Facet on head of rib for articulation with
vertebral body
Depressions
Notch
Groove or sulcus
Fossa
Greater sciatic notch of hip bone
Bicipital groove of humerus
Olecranon fossa of humerus, acetabular fossa of hip
bone
Opening
Fissure
Foramen
Canal
Meatus
Superior orbital fissure
Infraorbital foramen of the maxilla
Carotid canal of temporal bone
External acoustic meatus of temporal bone