skeletal system

Question 1

when does bone growth cease?

Answer 1

once epiphyseal plates ossify growth ceases leaving an epiphyseal line
hyaline c,t remains at end of long bones “articular c.t)

Question 2

what is ossification vs calcification?

Answer 2

ossification- process of creating bone
calcification - build up of calcium in soft tissue causing it to harden, can occur in damaged/diseased tissue as well as growing bone
is an aspect of ossification

Question 3

what is bone remodelling?

Answer 3

ongoing osteoclast and osteoblast activity throughout life
influenced by several factors

Question 4

what are the five factors related to bone-remodelling?

Answer 4

1. hormones- parathyroid hormone and calcitonin
   regulate calcium and phosphate levels in blood by putting excess calcium into bone or removing calcium from bones and estrogen/testosterone increase osteoblast proliferation and activity
2. mechanical stress- weight bearing exercise increases bone density (increases osteoblast activity)
3. in responce to damage- fracture-osteoblast repair- bone callus reshaped by osteoclasts
4. age- bone degration exeeds bone building (osteopenuia) at 40 bone thinning can progress to osteoporosis
5. nutrition- calcium- required for bone formation/repair
   vitamin d- required for absorption of dietary ca+

Question 5

what are bone markings?

Answer 5

surface features
reflect functional relationship to soft structures (tendons, muscles, ligaments, nerves)

Question 6

what are the three bone marking functional classifications?

Answer 6

1. depressions and openings
2. projections(processes) that form joints
3. projections for muscle and ligament attachment

Question 7

how many facial bones are there and what are they?

Answer 7

14
1. zygomatic (R&L cheekbones)
2. lacrimal (R&L foramina here drains tears)
3. nasal (R&L with nasal c.t from external nose)
4. vomer(with septal c.t forms nasal septum)
5.mandible(forms lower jaw and chin)
6.maxilla (forms upper jaw and hard palate)
7. ossicles ( malleus, incus, stapes of middle ear
8. hyoid bone (only bone that does not articulate with any other bones in the body)

Question 8

vertebral column?

Answer 8

24 individual vertebrae + 9 fused vertebrae = 33 vertebrae
houses and protects spinal cord
separated by intervertebral discs (fibrocartilage)
normal s shape curve which functions like a spring

Question 9

what are the two major divisions of the skeleton?

Answer 9

axial skeleton- skull, vertebral column, bony thorax ( ribs and sternum)
appendicular skeleton- pelvic girdle and legs, pectoral girdle and arms (clavicles and scapulae)

Question 10

what bones and cavities does the skull contain?

Answer 10

cranial and facial bones
some skulls contain sinuses which are air-filled cavities lined in mucous membrane

Question 11

what does the cranium house and how many bones does it consist of?

Answer 11

houses the brain which sits in the cranial cavity
8 large flat bones joined by fissures interlocking fibrous joints which permit growth of the skull and ossifiy in middle age

Question 12

what are the 8 bones in the cranium?

Answer 12

1.frontal bone- forms forehead ]
2.parietal bone- R&L forms sides of cranium
3.occipital bone- back of head- occipital condyles articulate with vertebral column foraman magnum here
4. temporal bone- R&L temples auditory meatus entrance to ear, mastoid process for attachment of mastication muscles
5. sphenoid bone- forms floor of cranium and orbit of eye sella turica, pituitary sits here
6. ethmoid bone- forms orbit and nasal cavity with nasal conchae well as anterior floor of cranium: cribiform plate with olfactory foramina

Question 13

what are the three regions of the vertebral structure?

Answer 13

7 cervical vertebrae c1-c7
12 thoracic vertebrae t1-t12
5 lumbar vertebrae l1-l5

Question 14

what is atlas vs axis?

Answer 14

atlas c1articulates with skull
axis c2 articulates with atlas permits rotation of head

Question 15

what does the sacrum consist of?

Answer 15

formed from fusion of s1-s5
center of gravity for body
4 pairs of foramina for passage of blood vessels and nerves
articulates with ilium of hip- sacroniac joint

Question 16

difference between annulus fibrosus vs nucleus pulposus

Answer 16

annulus is outer ring of fibrocartilage on vertebrae
nucleus is the inner gelatinous material

Question 17

what is the bony thorax?

Answer 17

thoracic vertebrae+ ribs+ sternum
framework of chest protects the heart/lungs

Question 18

what is the sternum?

Answer 18

manubrium+ body(with xiphoid process)
protects the heart

Question 19

what are the ribs?

Answer 19

bowed flat bones
attached to body of sternum by hyaline c.t (costal cartilage)
protects the lungs
head articulates with the thoracic vertebrae
12 pairs

Question 20

describe the pairs of the ribs?

Answer 20

12 pairs
7 pairs of true ribs which attach directly to sternum
5 pairs false ribs
3 pairs attached to costal cartilage
2 pairs floating not attached to anything

Question 21

what are the clavicles?

Answer 21

collarbones
articulates with sternum at sternal end and scapula acrominal end
curved long bones that brace shoulder

Question 22

what are the scapulae?

Answer 22

shoulderblades
triangular flat bones
glenoid fossa-articulates with head of humerous
acromion- articulates with clavicle

Question 23

what are the upper arms?

Answer 23

humerous articulates with glenoid fossa of scapula for form the shoulder joint

Question 24

what are the lower arms?

Answer 24

ulna (medial) and radius (lateral)
artiulcate with humerous to form elbow joint

Question 25

what is the elbow?

Answer 25

olecranon process of the ulna

Question 26

where do the radius and ulna artoulcate both proximally and distally at?

Answer 26

radioulnar joints and along their length by an interosseous membrane to permit roation of the radius over the ulna

Question 27

what does the hand consist of?

Answer 27

phalanges (finger bones) and metacarpals (palm bones) and carpals (wrist bones)
each finger consist of a proximal, middle, and distal phalanx except the thumb pollex which consists of only 2 phalanges

Question 28

what is the pelvic girdle? (hip girdle)

Answer 28

comprimised of right and left coxal bones
each coxal bone formed from 3 bones
ilium and ischium and pubis

Question 29

what does the upper leg consist of?

Answer 29

femur
articulates with acetabulum of coxal bone to form hip joint

Question 30

what does the lower leg consist of?

Answer 30

tibia and fibula
tibia articulates with condyles of femur to form knee joint

Question 31

what does the feet consist of?

Answer 31

phalanges (toes) and metatarsals (foot bones) and tarsals (ankle/heel bone)
each toe consists of 3 phalanges except the big toe hallux which consists of 2 phalanges