5.3 Spine anatomy and Biomechanics

Question 1

How many vertebrae are there in each section?

Answer 1

7C
12 T
5 L
Sacrum

Question 2

What is unique about the cervical vertebrae

Answer 2

Bifid spinous processes for the attachment of ligamentum nuchae
Presence of the transverse foramen for the vertebral artery and vein

Question 3

What is the body: canal ratio for each vertebrae/

Answer 3

C: 1:1
T 3:1
L 5:1

Question 4

What are the names of C1 and C2

Answer 4

1: Atlas
2: Axis

Question 5

In what plane do the articular processes lie?

Answer 5

C: transverse
T: coronal
L: saggital

Question 6

What is the unique feature of the thoracic vertebrae?

Answer 6

3 costal facet joints on each side

Question 7

With what ribs do each thoracic vertebrae articulate?

Answer 7

The one of the same number and the one below

Question 8

What is the distinguishing feature of the lumbar vertebrae?

Answer 8

Long transverse process for attachment of the lumbar muscles and a large body

Question 9

What are the erector spinae muscles?

Answer 9

Semispinalis, spinalis, longissimus and iliocostalis

Question 10

What are the cancers that commonly metastasise to the spine and why?

Answer 10

Lung, breast and bowel

These veins do not have valves so you get retrograde spread through the venous system

Question 11

Where does the nerve root exit?

Answer 11

above the vertebrae of the same name

Question 12

Where does the spinal cord terminate

Answer 12

L1 in adults

Question 13

What prevents excessive movements of the spine?

Answer 13

The back muscles - they protect the bones from exceeding their limits and cause a dampening effect

Question 14

What are the layers of the IV disc and what is each layer made of?

Answer 14

Inner = nucleus propolsus (mainly water)
Outer = annulus fibrosis (mostly collagen)

Question 15

What increases or decreases the inter-disc pressure?

Answer 15

Lying down reduces by 50%

Sitting increases by 50% due to the loss of lumbar lordosis