4: Skeletal Anatomy

Question 1

bone marking

Answer 1

an area on the surface of a bone related to specific function e.g. joint formation, muscle attachment, passageway for nerves and blood vessels

Question 2

axial skeleton

Answer 2

longitudinal axis of body
80 bones
skull
rib cage and sternum
vertebral column

Question 3

appendicular skeleton

Answer 3

limbs
pectoral and pelvic griddle
126 bones

Question 4

the skull

Answer 4

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

Question 5

facial bones functions

Answer 5

support cavities and the sense organs
protection
attachment of muscles to control facial expressions and manipulate food
only mandible moveable

Question 6

the facial bones

Answer 6

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

Question 7

paranasal sinuses

Answer 7

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

Question 8

skull growth

Answer 8

at birth, cranial bones connected by arms of fibrous connective tissue (cartilage)
large fibrous areas between cranial bones called fontanelles

Question 9

vertebral column

Answer 9

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

Question 10

spinal curve

Answer 10

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

Question 11

vertebral anatomy

Answer 11

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

Question 12

cervical vertebrae

Answer 12

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

Question 13

thoracic vertebrae

Answer 13

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

Question 14

lumbar vertebrae

Answer 14

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

Question 15

sacrum

Answer 15

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

Question 16

coccyx

Answer 16

3-5 (usually 4) fused vertebrae not complete until late adulthood

Question 17

thoracic cage

Answer 17

consists of thoracic vertebra, ribs and sternum
protects heart, lungs, and other internal organs
base for muscles involved in respiration

Question 18

ribs

Answer 18

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

Question 19

sternum

Answer 19

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

Question 20

pectoral girdles

Answer 20

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

Question 21

clavicles

Answer 21

articulates with manubrium of sternum and with the process of the scapula, the acromion

Question 22

scapulae

Answer 22

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)

Question 23

humerus

Answer 23

head articulates with scapula
several sites for muscle attachment
condyles articulate with bones of forearm

Question 24

radius and ulna

Answer 24

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

Question 25

bones or wrist and hand

Answer 25

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)

Question 26

pelvic girdle

Answer 26

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

Question 27

hip bone (coxal bone)

Answer 27

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

Question 28

pelvis

Answer 28

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

Question 29

femur

Answer 29

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

Question 30

tibia and fibula

Answer 30

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

Question 31

bones of foot and ankle

Answer 31

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