S2) Vertebral Column

Question 1

What is the vertebral column?

Answer 1

The vertebral column is a vertical series of approx. 33 small vertebrae bones, which are separated by intervertebral discs

Question 2

What are the five main functions of the vertebral column?

Answer 2

- Support: carries the weight of the body above the pelvis

- Haemopoiesis: red bone marrow production

- Axis: forms the central axis of the body

- Movement: highly flexible structure

- Protection: encloses and protects the spinal cord and the cauda equina within the spinal canal

Question 3

Identify the sections of the vertebral column as well as the number of vertebrae found in each

Answer 3

Question 4

All vertebrae share a basic common structure.

Describe it

Answer 4

• Consists of an anterior vertebral body
• Consists of a posterior vertebral arch

Question 5

Describe the structure, function and location of the vertebral body

Answer 5

• Structure: hyaline cartilage lines superior and inferior aspects
• Function: weight-bearing component (size increases as the vertebral column descends)
• Location: anterior part of the vertebrae

Question 6

What separates adjacent vertebral bodies?

Answer 6

Adjacent vertebral bodies are separated by a fibrocartilaginous intervertebral disc (annulus fibrosis)

Question 7

What is the vertebral foramen and why is it significant?

Answer 7

• The vertebral foramen is an enclosed hole formed by the vertebral body and the vertebral arch

- The foramina of the all vertebrae line up to form the vertebral canal, which encloses the spinal cord

Question 8

Identify the 5 different bony prominences on a typical vertebrae

Answer 8

Question 9

Identify the 3 distinguishing characteristics of the cervical vertebrae

Answer 9

• Bifid spinous processes (except C7)
• Transverse foramina (conduct the vertebral arteries)
• Triangular vertebral foramen

Question 10

Identify the 4 distinguishing characteristics of the thoracic vertebrae

Answer 10

• Two ‘demi facets‘ on each side of the vertebral body (articulate with head of the respective rib, and inferior rib)
• Costal facets on transverse processes (articulation with respective rib)
• Spinous processes are slanted anteroinferiorly
• Circular vertebral foramen

Question 11

Identify 2 distinguishing characteristics of the lumbar vertebrae

Answer 11

• Large kidney-shaped vertebral bodies
• Triangular vertebral foramen

Question 12

Identify 2 distinguishing characteristics of the sacral vertebrae

Answer 12

• Five fused vertebrae
• Facets on lateral walls (articulation with the pelvis at the sacro-iliac joints)

Question 13

Identify 3 distinguishing characteristics of the coccyx vertebrae

Answer 13

• Fused vertebral bodies
• No vertebral arches
• No vertebral canal (does not transmit the spinal cord)

Question 14

Identify and describe the major joints of the vertebral column

Answer 14

• Fibrocartilaginous joints: between vertebral bodies (indirectly)
• Facet joints: between inferior and superior articular processes
• Costovertebral joints: between head of rib and thoracic vertebral body
• Costotransverse joints: between tubercle of rib and thoracic transverse process

Question 15

Identify the two ligaments that strengthen the vertebral fibrocartilaginous joints and describe their function

Answer 15

• The anterior longitudinal ligament is thick and prevents hyperextension of the vertebral column
• The posterior longitudinal ligament is weaker and prevents hyperflexion of the vertebral column

Question 16

Identify the four ligaments which strengthen the facet joints in the vertebral column

Answer 16

• Ligamentum flavum
• Interspinous ligaments
• Supraspinous ligaments
• Inter transverse ligaments

Question 17

Describe the structure and location of the ligamentum flavum

Answer 17

• Structure: yellow in colour, composed of elastic fibres
• Location: extends from lamina to lamina of adjacent vertebrae

Question 18

Describe the structure and location of the interspinous ligaments

Answer 18

• Structure: relatively weak sheets of fibrous tissue, fused with supraspinous ligaments
• Location: extends between spinous processes of adjacent vertebrae

Question 19

Describe the structure and location of the supraspinous ligaments

Answer 19

• Structure: strong bands of white fibrous tissue
• Location: extend between tips of adjacent spinous processes

Question 20

Describe the structure and location of the inter transverse ligaments

Answer 20

• Structure: blend with intertransverse muscles

- Location: extends between transverse processes

Question 21

Describe the structure and function of the intervertebral discs

Answer 21

• Structure: consists of nucleus pulposus (central) and annulus fibrosus (peripheral)
• Function: account for 25% of the length of the vertebral column

Question 22

Describe the composition of the intervertebral discs

Answer 22

• 70% Water
• 20% Collagen
• 10% Proteoglycans

Question 23

Describe the structure, function and location of the annulus fibrosis

Answer 23

• Structure: outer lamellae of Type 1 collagen and fibrocartilaginous inner lamellae, avascular and aneural
• Function: major ‘shock absorber’
• Location: surrounds nucleus pulposus

Question 24

Describe the structure and location of the nucleus pulposus

Answer 24

• Structure: remnant of notochord, gelatinous, Type 2 collagen
• Location: surrounded entirely by annulus fibrosus

Question 25

A slipped disc is a herniation commonly occurring at L4/5 and L5/S1. Identify the four different types

Answer 25

- **Disc degeneration:** aging causes disc to dehydrate and bulge **- Prolapse**: protrusion of the nucleus pulposus with slight impingement into the spinal canal (contained) **- Extrusion**: nucleus pulposus breaks through annulus fibrosus (undisplaced) **- Sequestration**: nucleus pulposus breaks through annulus fibrosus and separates from the main body of the disc (displaced)

Question 26

What are the types of disc prolapse?

Answer 26

- **Lateral disc protrusion** usually compresses the nerve root above (5%) - **Paracentral disc protrusion** usually compresses the nerve root below (95%)

Question 27

In a paracentral herniation of the L4/5 disc, why is the L5 root is most frequently compressed?

Answer 27

The L5 root is compressed as the L4 root emerges above the level of the L4/5 disc (but below the L4 vertebrae)

Question 28

What is sciatica?

Answer 28

**Sciatica** is the compression of the nerve roots which contribute to the sciatic nerve

Question 29

Identify the different types of sciatica and the parts of the limb affected

Answer 29

- **L4 Sciatica** – anterior thigh, anterior knee, medial shin - **L5 Sciatica** – lateral thigh, lateral calf, dorsum of foot - **S1 Sciatica** – posterior thigh, posterior calf, heel, sole of foot

Question 30

What is Cauda Equina Syndrome?

Answer 30

**Cauda equina syndrome** is a serious condition that comes with extreme pressure and swelling of the nerves at the end of the spinal cord

Question 31

Identify 5 red flag signs/symptoms of cauda equina syndrome

Answer 31

- Bilateral sciatica - Perianal numbness - Painless retention of urine - Urinary / faecal incontinence - Erectile dysfunction

Question 32

What is lumbar spinal stenosis?

Answer 32

- **Lumbar spinal stenosis** (LSS) is a clinical condition in which the spinal canal narrows and compresses the spinal cord and nerves at the level of the lumbar vertebrae - It is caused by ageing, spinal disc herniation, osteoporosis or a tumour

Question 33

What is neurogenic claudication?

Answer 33

**Neurogenic claudication** is a common symptom of lumbar spinal stenosis or inflammation of the spinal nerves involving pain in the legs during motion

Question 34

In 5 steps, describe the pathophysiology of neurogenic claudication

Answer 34

⇒ **Venous engorgement** and **arthritis** causes osteophyte formation ⇒ Spinal canal **narrows** ⇒ **Blood supply** to nerve is limited ⇒ Nerve roots become **ischaemic** ⇒ **Pain** occurs during motion

Question 35

What is spondylolisthesis?

Answer 35

**Spondylolisthesis** is a slip forwards of the vertebrae above on the vertebra below due to a fracture in the pars interarticularis

Question 36

What are the different types of spondylolisthesis?

Answer 36

- Dysplastic (abnormality in facet joint shape) - Isthmic (pars interarticularis defect) - Degenerative - Iatrogenic - Pathological

Question 37

Which part of the vertebrae is known as pars interarticularis?

Answer 37

**Pars interarticularis** is located between the superior and inferior articular process of the facet joint

Question 38

Distinguish between the following terms: - Spondylosis - Spondylitis - Spondylolysis - Spondylolisthesis

Answer 38

**- Spondylosis:** age-related wear and tear to bones of the spine **- Spondylitis:** inflammation of the joints of the spine **- Spondylolysis:** fractures in pars interarticularis **- Spondylolisthesis:** movement of one vertebrae relative to the ones above/below it

Question 39

Describe the structure of the foetal vertebral column

Answer 39

The **vertebral column** is flexed in a single C-shaped curvature (primary curvature) which is concave anteriorly (kyphosis)

Question 40

Where is the primary curvature maintained in adult life?

Answer 40

- Thoracic region - Sacral region - Coccygeal region

Question 41

Describe the structure of the vertebral column in the young adult

Answer 41

4 distinct curvatures: - **K****yphoses** (anterior flexions): thoracic and sacrococcygeal - **Lordoses** (posterior flexions): cervical and lumbar

Question 42

Describe the development of the secondary curvatures

Answer 42

**- Cervical lordosis** appears when young child begins to lift its head - **Lumbar lordosis** develops when child begins to standup and walk

Question 43

Senile kyphosis develops in old age. What is this?

Answer 43

**Senile kyphosis** – secondary curvatures start to disappear and the continuous primary curvature is re-established

Question 44

Describe the structure of the vertebral column during pregnancy

Answer 44

Exaggeration of lumbar lordosis

Question 45

What are the weak points of vertebral column (centre of gravity)?

Answer 45

- C1 & C2 - C7 & T1 - T12 & L1 - L5 & S1