4: Skeletal Anatomy Flashcards
bone marking
an area on the surface of a bone related to specific function e.g. joint formation, muscle attachment, passageway for nerves and blood vessels
axial skeleton
longitudinal axis of body
80 bones
skull
rib cage and sternum
vertebral column
appendicular skeleton
limbs
pectoral and pelvic griddle
126 bones
the skull
8 cranium bones that protect brain
12 facial bones for support and protection
frontal bone = forms the forehead and roof of orbits (eye sockets)
parietal bones = on either side of skull, roof of cranium
occipital bone = base of skull, foramen magnum (large hole) for spinal cord
temporal bones = sides of cranium, forms structure of inner ear and pat of cheek bone
sphenoid bone = junction between cranial and facial bones
ethmoid bone = forms roof and sides of nasal cavity
facial bones functions
support cavities and the sense organs
protection
attachment of muscles to control facial expressions and manipulate food
only mandible moveable
the facial bones
maxillary bones = central bones, upper jaw, largest facial bone
palatine bones = form roof of mouth
vomer = forms part of nasal septum
zygomatic bones = completes lateral wall of orbit
nasal bones = bridge of nose
lacrimal bones = medial surface within orbit
mandible = lower jaw
hyoid bone = U-shaped bone suspended below skull
paranasal sinuses
air filled chambers in some cranial/facial bones
make skull lighter
extensive area of mucous epithelium
mucous secretion into nasal cavities that warms, moistens and filters particles out of incoming air
skull growth
at birth, cranial bones connected by arms of fibrous connective tissue (cartilage)
large fibrous areas between cranial bones called fontanelles
vertebral column
24 vertebrae, plus sacrum and coccyx
provides column of support
protects spinal cord an helps maintain upright body position
7 cervical vertebrae
12 thoracic vertebrae
5 lumbar vertebrae
sacrum is single bone formed by fusion of 5 vertebrae
coccyx is small single bone also made fused vertebrae
spinal curve
primary curves = thoracic and sacral curves because they are present at birth
secondary curves = cervical and lumbar curves as they develop several months after birth
kyphosis = exaggerated thoracic curvature
lordosis = exaggerated lumbar curvature
scoliosis = abnormal lateral curvature of spine
vertebral anatomy
vertebral body = bigger weight bearing portion of a vertebra
intervertebral disc = made of fibrocartilage and lies between each body to prevent contact
vertebral arch = posterior section of each vertebral foramen (opening through which spinal cord passes), walls called pedicles and roof formed by lamina
vertebral canal = encloses spinal cord, comprised of vertebral foramina and successive vertebrae
transverse process = project laterally from pedicles, site for muscle attachment
spinous process = projects posteriorly from when laminae fuse together
articular process = articulate with vertebra above and below to form articular facets
cervical vertebrae
body relatively small
oval vertebral body
relatively large vertebral foramen
stumpy spinous process with notched tip
round transverse foramina (hole through transverse process) to protect blood vessels supplying the brain
C1 = atlas, holds up head
C2 = axis, together with alas forms a pivot joint to rotate head
thoracic vertebrae
size of vertebrae foramen decreases as go down as spinal cord decreases in diameter
vertebral bodies gradually enlarge downwards to bear more weight
heart shaped body bigger than cervical vertebrae body
large slender spinous process
costal facets on body and transverse processes for articulating with ribs
lumbar vertebrae
largest vertebrae
thick oval body
relatively massive stumpy spinous process
blade like transverse process
vertebrae most important for weight bearing
lumbar discs (in-between vertebrae) are thickest to absorb shock
sacrum
triangular shaped
apex = narrow portion
base = broad superior surface
sacral canal = passageway through sacrum
sacral promontory = prominent bulge at anterior tip of base
four pairs of sacral foramina open on either side
coccyx
3-5 (usually 4) fused vertebrae not complete until late adulthood
thoracic cage
consists of thoracic vertebra, ribs and sternum
protects heart, lungs, and other internal organs
base for muscles involved in respiration
ribs
long, curved flattened bones
12 pairs of ribs
articulate on or between thoracic vertebrae and end in wall of thoracic cavity
first 7 pairs are true ribs - connect to the sternum by separate cartilaginous extensions called costal cartilages
ribs 8-12 called false ribs - do not attach directly to sternum, costal cartilages fuse and merge with cartilages of rib pair 7
last two pairs o ribs called floating ribs - no connection with sternum
ribs provide attachment site for muscles of the pectoral girdles and trunk
sternum
3 parts:
broad triangular manubrium articulates with the clavicles and the cartilages of the first pair of ribs
elongate body
bottom of the body called xiphoid process
pectoral girdles
pectoral girdle = where each upper limb articulates with trunk
consists of 2 broad flat scapulae and 2 slender curved clavicles
scapular and clavicles extremely important for muscle attachment
clavicles
articulates with manubrium of sternum and with the process of the scapula, the acromion
scapulae
have a superior, lateral and medial boarder
triangle shape - three tips called the superior, inferior and lateral angle
scapula forms shoulder joint at glenoid cavity
depression on scapula called subscapular fossa
two processes at shoulder, coracoid (anterior) and acromion (posterior)
humerus
head articulates with scapula
several sites for muscle attachment
condyles articulate with bones of forearm
radius and ulna
radius lies lateral (thumb side), ulna provides medial support of forearm
olecranon of the ulna is the point of the elbow
trochlear notch of ulna articulates with trochlear of humerus at elbow joint
head of radius articulates with capitulum of humerus at the elbow and with the ulna at the radial notch
pronation and supination allowed via radio-ulna joint
bones or wrist and hand
27 bones
8 carpal bones (two rows of 4) articulate with radius and metacarpals
5 metacarpals
14 phalanges (3 in each finger and 2 in thumb)
pelvic girdle
pelvic girdle articulates with the thigh bones
consists of 2 hip bones (coxal bones) - each formed by the fusion of ilium, ischium and pubis
posteriorly, hip bones articulate with sacrum at sacro-iliac joints
head of femur articulates with curved surface of the acetabulum
hip bone (coxal bone)
ilium is most superior and largest component of hip bone, board surface for muscle, tendons and ligament attachment
iliac crest marks sites of attachment for muscles and ligaments
ilium fuses with ischium
ischium fuses with pubis around obturator foramen
pelvis
pelvis consists of the two hip bones, sacrum and coccyx
lots of ligaments for stability
females different to male due to body size and muscle mass, females pelvis smoother, lighter and less prominent markings
females adapted for childbirth so is broad and lower, wider pubic angle
femur
longest and heaviest bone in body
head articulates with pelvis at acetabulum
greater and lesser trochanters = projections extending laterally from neck and shaft
epicondyles at end of shaft
patella glides over surface between lateral and medial condyles
tibia and fibula
tibia - shin bone, large medial bone
lateral and medial condyles of femur articulate with lateral and medial condyles of tibia
patella ligaments connect patella to tibial tuberosity
medial malleolus at the bottom of tibia provides medial support for ankle
fibular articulates with tibia inferior to lateral condyle of tibia
fibula doesn’t articulate with femur or help transfer weight to foot
fibular is important surface for muscle attachment and distal lateral malleolus provides lateral stability for ankle
bones of foot and ankle
7 tarsal bones
talus (a tarsal bone) articulates with the tibia and fibula
calcaneus known as heel bone, most of weight goes through
5 metatarsals which support the sole
big toe (hallux) has 2 phalanges, other toes have 3
arches in foot to transfer weight
