3. The spine

Question 1

how many vertebrae in spine

Answer 1

33

Question 2

name the different types of vertebrae, how many, and how mobile

Answer 2

• 7 cervical: mobile
• 12 thoracic: relatively immobile
• 5 lumbar: mobile
• 5 sacral: fused
• 4 coccygeal: fused

Question 3

describe the curvatures of the vertebral column

Answer 3

1. cervical - lordosis
2. thoracic - kyphosis
3. lumbar - lordosis
4. sacral - kyphosis

Question 4

which vertebrae does the centre of gravity run through

Answer 4

C1/2… C7/T1… T12/L1… L5/S1

Question 5

describe the development of spine curvatures during ageing

Answer 5

1. primary curvature: foetus flexed in single C-shaped kyphosis

secondary curvatures:

2. cervical lordosis develops as child begins to lift head
3. lumbar lordosis develops as child begins to crawl, stand and walk
4. senile kyphosis: loss of secondary curvatures in old age

Question 6

what separates adjacent vertebrae

Answer 6

intervertebral discs

Question 7

what % of spinal column do IV discs make up

Answer 7

25%

Question 8

what are IV discs composed of

Answer 8

70% water, 20% collagen, 10% proteoglycans

Question 9

name the 2 regions of IV discs

Answer 9

1. peripheral annulus fibrosus

2. central nucleus pulposus

Question 10

how are the 2 IV disc regions different

Answer 10

annulus fibrosus

• made up of lamellae of annular bands; outer lamellae = type I collagen, inner lamellae = fibrocartilage
• acts as major shock absorber

nucleus pulposus

• gelatinous notochord remnant made of type 2 collagen
• high osmotic pressure