Intervertebral Discs and Functional Anatomy of the Back

Question 1

What two things do each intervertebral disc consist of?

Answer 1

annulus fibrosis - an outer fibrous part formed of concentric lamella of fibrocartilage
nucleus pulposus - a gelatinous central mass

Question 2

How many intervertebral discs are there?

Answer 2

23 or 24 if you count joint between sacrum and coccyx

Question 3

How do IV discs vary as you go down the back?

Answer 3

increase in size from cervical (3mm), to thoracic (5mm) to lumbar (9-11cm)

Question 4

How is the IV disc separated from the bone of the vertebral body?

Answer 4

by a thin hyaline cartilage layer

Question 5

Describe how disc degeneration occurs with ageing

Answer 5

discs become more calcified in old age, nucleus pulposus dries out and as IV discs degenerate it can compress the spinal roots, especially within the lumbar region

Question 6

What are ‘zygapophysial joints’?

Answer 6

type of joint that exists between the inferior and superior articular processes of adjacent vertebra and they act as synovial planar joints which facilitate sliding movements as well as forming intervertebral foramen to allow the passage of spinal nerves

Question 7

Name the 4 main ligaments of the vertebral column

Answer 7

anterior longitudinal ligament, posterior longitudinal ligament, ligament flava and interspinous ligaments

Question 8

Describe the structure of the anterior longitudinal ligament

Answer 8

strong, broad fibrous band which covers and connects anterior aspects of the vertebral bodies and intervertebral discs. It extends from the pelvic surface of the sacrum to the atlas at C1 and the occipital bone

Question 9

Describe the function of the anterior longitudinal ligament

Answer 9

functions to maintain the stability of the IV joints by limiting the extension possible of the vertebral column

Question 10

Describe the structure of the posterior longitudinal ligament

Answer 10

narrower and weaker band than the ALL and it runs within the vertebral canal on the posterior aspect of the vertebral bodies of the discs. This ligament is mainly attached to the intervertebral discs and extends from C2 to the sacrum

Question 11

Describe the function of the posterior longitudinal ligament

Answer 11

helps to prevent hyperflexion

Question 12

Describe the structure of the ligament flava

Answer 12

extends from the lamina above to the lamina below of adjacent vertebra and acts to resist separation between the two.

Question 13

Describe the function of the ligament flava

Answer 13

Helps to stop abrupt flexion and the ligaments are highly elastic so they can assist with the straightening of the vertebral column after flexion

Question 14

Describe the interspinous ligaments

Answer 14

these join adjacent spinous processes and is a weak ligament that is more like a thin membrane

Question 15

What is flexion of the spine?

Answer 15

bending forwards

Question 16

What is extension of the spine?

Answer 16

leaning backwards

Question 17

What is lateral extension of the spine?

Answer 17

standing upright

Question 18

What is lateral flexion of the spine?

Answer 18

leaning to one side

Question 19

What is rotation at the spine?

Answer 19

rotation at neck or trunk (lateral or medial)

Question 20

Which muscles are involved in flexion of the spine?

Answer 20

rectus abdominis and psoas major

Question 21

Which muscles are involved in extension of the spine?

Answer 21

erector spinae and gluteus maximus