Unit 3 - Spinal cord & vertebrae

Question 1

name the regions of the vertebral column

Answer 1

• cervical vertebrae (C1-8)
• thoracic vertebrae (T1-12)
• lumbar vertebrae (L1-5)
• sacrum (S1-5) - fused
• coccyx (1-4) - fused

Question 2

what are the distinguishing features of the cervical vertebrae?

Answer 2

• small vertebral body
• bifid spinous process (apart from c1 and c7)
• transverse foramina
• triangular vertebral foramen
  (c1 = atlas, c2 = axial - movement of the head)

Question 3

what are the distinguishing features of the thoracic vertebrae?

Answer 3

• increase in size from superior to inferior
• demi-facets/ costal facets to articulate with ribs
• circular vertebral foramen

Question 4

what are the distinguishing features of the lumbar vertebrae?

Answer 4

• large vertebral body - no facets/ processes

- triangular shaped vertebral foramen

Question 5

what are the distinguishing features of the sacral vertebrae?

Answer 5

no vertebral arch = no vertebral canal

facets for articulation of pelvis

Question 6

give four clinical syndromes resulting from abnormal curvature of the spine

Answer 6

• kyphosis: curvature of thoracic vertebrae (hunchback)
• lordosis: curvature of lumbar vertebrae (swayback)
• scoliosis: lateral curvature of spine
• cervical spondylosis - decrease in size of intervertebral foramen due to degeneration of joints in spine - pressure on nerves

Question 7

describe the structure found inbetween vertebrae

Answer 7

intervertebral discs - consists of fibrocartilage - outer layer: anulus fibrosum and inner layer nucleus pulposus
side of discs forms anterior margin of the intervertebral foramen

Question 8

what ligaments limit flexion of the spine?

Answer 8

ligamentum flavum (chiefly limits) - runs in front of lamina
interspinous and supraspinous ligaments - connect spinous processes

Question 9

what are the differences in the two types of longitudinal ligaments?

Answer 9

anterior: covers front and sides of the vertebral bodies
- limits extension of spine prevents backward/ forward movement of vertebral bodies relative to each other
posterior: covers back of the vertebral bodies - limits flexion of the vertebral bodies

Question 10

where does the spinal cord extend from/to?

Answer 10

foramen magnum to L2 - ends at conus medullaris

Question 11

what are the three meningeal layers that surround the spinal cord and what is their function?

Answer 11

dura mater/ arachnoid mater/ pia mater
protects and stabilises the cord within bony surroundings
- contains CSF between arachnoid and pia mater in subarachnoid space

Question 12

what are the paired extensions of the pia mater that anchor the cord and attach to dura mater?

Answer 12

denticulate ligaments (between anterior/ posterior roots of nerves)
filum terminale- anchors cord to coccyx

Question 13

what are the arachnoid trabeculae?

Answer 13

small strands of tissue containing spinal blood vessels

Question 14

describe the regions of spinal nerves

Answer 14

31 spinal nerves in total
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal nerve

Question 15

where are the two enlargements of the spinal cord?

Answer 15

• cervical: c5-t1 - gives rise to brachial plexus - innervates upper limb
• lumbosacral: l2-s3 - gives rise to lumbosacral plexus - innervates the lower limb

Question 16

where is the lumbar cistern located?

Answer 16

between l1/ 2 - contains CSF

Question 17

what surface marking marks the position of S2 and what does this represent?

Answer 17

sacral dimple - subarachnoid space ends

Question 18

where can you find where the spinal cord ends?

Answer 18

top of iliac spine - gives position of L4 - go up two spinal levels

Question 19

what are the roots of the spinal cord and what do they combine to form?

Answer 19

ventral and dorsal roots - form segmental nerve (spinal nerve)
(ventral = motor/ dorsal = sensory)

Question 20

what is a dermotome?

what is a myotome?

Answer 20

area of skin innervated by spinal nerves

group of muscles that a single spinal nerve innervates

Question 21

how many dermatomes are they?

what dermatomes do nipple line,umbilicus and perianal region indicate?

Answer 21

29 = 7 cervical (no c1)/ 12 thoracic/ 5 lumbar/ 5 sacral

nipple - t4/ umbilicus - t10/ perianal region - s4/5

Question 22

what are the trigeminal dermatomes? - describe the region

Answer 22

• opthalmic - tip of nose to anterior edge of scalp
• maxillary - below corner of eye,around nostril to corners of mouth
• mandibular - below corners of mouth, to chin up to the temples