Musculoskeletal System: Vertebrae, Ribs and Body Segments Flashcards Preview

ANAT1003 test 2 > Musculoskeletal System: Vertebrae, Ribs and Body Segments > Flashcards

Flashcards in Musculoskeletal System: Vertebrae, Ribs and Body Segments Deck (49):
1

what does the axial skeleton consist of?

vertebrae, ribs, sternum and skull

2

what does the appendicular skeleton consist of?

limbs and girdle

3

what is the role of the axial skeleton?

to protect CNS (spinal cord and brain) and viscera (thoracic and abdominal), breathing movement, support and movement.

4

in how many places do the vertebrae articulate with each other?

2 places - between the bodies (via intervertabral discs) and between the arches

5

what protects the spinal cord?

neural arches

6

small spaces between the articulating vertebrae allow the exit of what from the spinal cord?

spinal nerves

7

how many cervical (neck) vertebrae are there?

7

8

what are some characteristics of cervical vertebrae?

small, no free ribs, low weight bearing, the first 2 cervicals (atlas and axis) are specialised to allow head movement.

9

what are the first two cervicals called?

atlas and axis

10

how many thoracic vertebrae are there?

12

11

what are some characteristics of thoracic verterbrae?

medium sized, rib bearing (12 pairs of ribs)

12

how many lumbar vertebrae are there?

5

13

what are some characteristics of lumbar vertebrae?

large, high weight bearing, no free ribs

14

how many sacral vertebrae are there?

5

15

what are some characteristics of sacral vertebrae?

large, fused into a single mass to support weight of body and pelvis

16

how many coccygael (tail) vertebrae are there?

1-2

17

what are some characteristics of coccygael vertebrae?

tiny and vistigal

18

which is the part of the spinal cord that is most often damaged in humans?

lumbar region

19

where is the lumbar region in a human?

it lies between the thorax and pelvis

20

what is osteoporosis?

when the lumbar region collapses which crushes the lumbar spinal nerves leading to pain in the back and legs

21

what is the function of osteoblasts and osteoplasts?

remove and replace bone cells

22

what are axial muscles?

intercostal muscles, abdominal wall muscles, deep back muscles

23

where would you find epaxial muscles?

above/dorsal to the ribs

24

where would you find hypaxial muscles?

below/ventral to the ribs

25

what do epaxial muscles do?

extend spine

26

what do hypaxial muscles do?

flex spine

27

does flexion increase or decrease the angle between structures?

decrease

28

does extension increase or decrease the angle between structures?

usually increase

29

in early vertebrate ancestors that had no vertebrae, what structure stiffened the body?

the notochord - a flexible mesodermal rod

30

in early vertebrate ancestors, where did the notochord lie?

immediately below the nerve cord

31

what does the notochord form in humans?

nucleus pulposus - the core of the vertebral column

32

what does the paraxial mesoderm form?

somites

33

what do somites split into?

sclertome and dermomyotome

34

what happens to sclerotomal cells?

sclerotomal calls break away from the somite and wrap around the notochord and neural tube, forming vertebrae

35

what happens to dermomoyotome?

breaks into dermatome and myotome

36

what does dermatome form?

epidermis of skin

37

what does myotome form?

skeletal muscle

38

what provides shock absorption in the spinal cord?

nucleus pulposus

39

what herniates in a slipped disc?

the nucleus pulposus

40

what does the myotome split into?

into dorsal (epimere) and ventral (hypomere) parts. forms epaxial and hypaxial muscles respectively. hypomere also forms limb muscles.

41

what are the three layers of intercostal muscles?

external, internal and innermost

42

what are the three layers of abdominal muscle?

external, internal and transverse

43

what forms BLOCKS of muscle and skin?

the dermomyotome of somites

44

what forms vertebrae (a series of repeating units)?

sclerotome

45

where is residual segmentation most obvious in adults?

in the thorax: intercostal muscles of chest wall; segmental pattern of blood vessels; segmental nerves to muscles and skin; ribs, vertebrae and sternal elements.

46

what do vertebrate animals show variation in?

vertebral numbers (no of segments = somites) and vertebral regionalisation (specification of segment identity)

47

how many cervical vertebrae do mammals have?

7

48

mammals developed a rib-less lumbar region. what does this allow?

greater dorsoventral flexion of the spine

49

What controls the anteroposterior axis during development?

hox genes