8.1 Osteology and Arthrology of the Vertebral Column & the Thoracic Cage

Question 1

Which sections of the vertebral column are the most/least mobile? Relate the least mobile region to underlying function.

Answer 1

Most mobile: lumbar
Least mobile: thoracic

Thorax is least mobile because we need to protect the organs within this section of the body.

Question 2

List 4 functions of the vertebral column

Answer 2

1. Weight transmission to pelvis and lower limbs
2. Protection of spinal cord
3. Attachment for muscles & ligaments
4. General bone function (e.g. mineral storage, haematopoiesis etc.)

Question 3

At what point do primary curvatures of the vertebral column develop? What is their purpose?

Answer 3

• Form during development
• Increase volume for internal organs to grow

Question 4

When do secondary vertebral curvatures develop? Why?

Answer 4

• Develop as we mature and begin to stand up
• We need them to support upright position

Question 5

List the key differentiating features of cervical vertebrae

Answer 5

• Short
• Horizontal
• Bifid spinous process
• Transverse foramina
• Oblique articular facets

Question 6

List the key differentiating features of thoracic vertebrae

Answer 6

• Downward pointing spinous process
• Superior and inferior costal facets for ribs
• Coronal articular facets (less movement)

Question 7

List the key differentiating features of lumbar vertebrae

Answer 7

• Short, hatchet-like spinous process
• Thick, chunky vertebral body
• Sagittal articular facets

Question 8

What are the 2 components of the intervertebral disc? What are they made of?

Answer 8

• Annulus fibrosus: outer fibrocartilage
• Nucleus pulpopus: internal gelatinous core

Question 9

What is a Jefferson’s fracture? What can cause it?

Answer 9

• Burst fracture of atlas
• Causes by severe force to superior skull (e.g. diving into shallow water)

Question 10

Spondylosis vs spondylolisthesis?

Answer 10

Spondylosis: fracture of one pars interarticularis

Spondylolisthesis: fracture of both parts interarticularis

Question 11

Recall the seven spinal ligaments. Which limit flexion/extension?

Answer 11

• Anterior/posterior longitundal
• Ligamentum flavum
• Interspinous
• Intertransverse
• Supraspinous
• Nuchal ligament

Anterior longitudinal limits extension; all else limit flexion.

Question 12

Fibrocartilage vs hyaline cartilage

Answer 12

• Fibrocartilage is stronger, contains many collagen fibres and is less common
• Hyaline cartilage is transparent, weaker, and more common

Question 13

1° vs 2° cartilaginous joints

Answer 13

1°: Hyaline cartilage
2°: Fibrocartilage

Question 14

What kind of joints are interchondral joints of the thorax?

Answer 14

Synovial gliding joint.

Question 15

What kind of joints are the costochondral joints?

Answer 15

Primary cartilaginous joints.

Question 16

What kind of joints are the sternocostal joints? (1st vs 2-7)

Answer 16

1st: Primary cartilaginous
2-7: Synovial gliding

Question 17

What type of joints are costovertebral and costotransverse?

Answer 17

Synovial gliding.

Question 18

Which of higher/lower thoracic vertebrae have one central costal facet vs superior and inferior demi-facets?

Answer 18

T2-T9 have two.

T10-T12 have one.

(Two digits have one, one digit has two; except first)

Question 19

Does the diaphragm contract when flattening or moving upward?

Answer 19

Flattening; like an umbrella.

Question 20

Which spinal nerves form the brachial and lumbar plexuses?

Answer 20

Brachial: C5-T1
Lumbar: L1-S3

Question 21

Why are posterior disc herniations more common than anterior disc herniations?

Answer 21

Anterior longitudinal ligament is much stronger than posterior longitudinal ligament. After all the PLL has to have holes for the pedicles etc.