Vertebral Column And Spinal Cord

Question 1

List the four curves and state when they appear

Answer 1

1. cervival(C2-T2) - 3 months
2. thoracic(T2-T12) .- present at birth
3. lumbar(T12-sacrovertbral angle) - 9th to 18th month when the child begins to sit and walk
4. sacral(sacrovetebral articulation-coccyx) -appears at birth

Question 2

Describe the external features of the spinal cord:l

Answer 2

1. Length- 42 to 45 cm
2. Extents: begins as an extension of medulla oblongata at the level of the upper border of C1
   - extends down to the lower border of L1 (varies with flexion and extension)
   - the lowest part is conical and is called conus medullaris
   - the conus is continuous below, with a fibrous cord called the filum terminale which is a prolongation of Pia mater and is attached to the posterior surface of the first piece of coccyx
3. Enlargements:
   -cervical C5-T1- brachial plexus
   -lumbar L1-S2 - lumbosacral plexus
4. Segments- 31 in total
   
   • according to number of spinal nerves; 8cervical, 12thoracic, 5lumbar,5sacral, 1coccygeal
5. Spinal meninges- duration, arachnoid, pia(forms 2 ligaments)
6. Meningeal spaces- epidural, subdural, subarachnoid
7. Lumbar cistern- part of subarachnoid space

Question 3

state the location and extents of the spinal cord

Question 5

parts if intervertebral discs and their functions

Answer 5

1. annulus fibrosus- made of tight collagen fibres to connect bodies
2. nucleus pulposus- absorbs shocks; remains of notochord; mostly water
3. intervertebral foramen- transmits nerve roots and radicular artery

Question 6

discuss the age changes in intervertebral discs

Answer 6

1. decreased water content
2. loss of elasticity
3. becomes thin
4. bone-bone friction
5. osteophyte formation

Question 7

effects of degenerated IVD

Answer 7

1. IVD prolapse
2. herniation
3. compression of nerve roots

Question 8

contents of vertebral canal

Answer 8

1. spinal cord till L1/L2
2. cauda equina below L1/L2
3. meninges and epidural space
4. internal vertebral venous plexus
5. epidural fat

Question 9

blood supply of spinal cord and vertebrae

Answer 9

1. anterior spinal artery- by union of anterior and posterior spinal arteries(which are branches of the fourth part of the vertebral artery)
2. 2 posterior spinal arteries- PICA- vertebral
3. radicular arteries - from:
   a.neck- vertebral and ascending arteries
   b. thorax- posterior intercostal arteries
   c. abdomen- lumbar arteries
   d. pelvis- lateral and median sacral arteries

Question 10

venous drainage of the vertebral column

Answer 10

vertebrae drain into internal venous plexus which in turn drains into external venous plexus

Question 11

spine abnormalities

Answer 11

1. spina bifida- occulta, meningocele, meningomyelocele
2. vertebral canal stenosis
3. abnormal curvatures

Question 12

discuss spina bifida occulta

Answer 12

1. defect in the vertebral arch with absence of the spine
2. defect is covered by skin and tuft of hair
3. spinal cord and meninges are in place
4. no manifestations( most patients don’t know they have it)
5. commonly occurs in the lumbosacral region

Question 16

Discuss lumbar cistern

Answer 16

Definition: part of subarachnoid space below the end of the spinal cord
Extents: L2-S2
Contents: Cauda equina, CSF, Filum terminale
Clinical importance: lumbar puncture
-insertion of needle into subarachnoid space to take sample of CSF for analysis
-Inject drugs like anesthetic or antibiotic
-Measure CSF pressure

Question 17

Discuss the articulation between 2 vertebra.

Answer 17

• Bodies articulate with each other by 3 structures:*
  1. Anterior longitudinal ligament
  2. IVD
  3. Posterior longitudinal ligament

Laminae:
• ligamentum flavum
Transverse processes:
• inter transverse ligament
Spines:
• interspinous ligament
• supraspinous ligament
Articular processes:
• synovial articulation

Question 18

Describe the typical vertebra.

Answer 18

parts:
1. Body (anterior)
2. Vertebral arch: (posterior)
- 2 pedicles
-2 laminae
-6 processes: 2 transverse, 2 superior articular and 2 inferior articular.
3. Vertebral canal- separates body and vertebral arch

Question 19

Discuss the features of the typical vertebra. ( How to distinguish them basically)

Answer 19

Cervical vertebra:
1. Have foramina- foramen transverserium.
2. Short bifid spine

Thoracic vertebra:
1. Costal facets- they articulate with ribs

Lumbar vertebra:
1. No costal facets
2. No foramen in transverse process