Vertebral Column And Spinal Cord Flashcards
List the four curves and state when they appear
- cervival(C2-T2) - 3 months
- thoracic(T2-T12) .- present at birth
- lumbar(T12-sacrovertbral angle) - 9th to 18th month when the child begins to sit and walk
- sacral(sacrovetebral articulation-coccyx) -appears at birth
Describe the external features of the spinal cord:l
- Length- 42 to 45 cm
- 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 - Enlargements:
-cervical C5-T1- brachial plexus
-lumbar L1-S2 - lumbosacral plexus - Segments- 31 in total
- according to number of spinal nerves; 8cervical, 12thoracic, 5lumbar,5sacral, 1coccygeal
- Spinal meninges- duration, arachnoid, pia(forms 2 ligaments)
- Meningeal spaces- epidural, subdural, subarachnoid
- Lumbar cistern- part of subarachnoid space
state the location and extents of the spinal cord
parts if intervertebral discs and their functions
- annulus fibrosus- made of tight collagen fibres to connect bodies
- nucleus pulposus- absorbs shocks; remains of notochord; mostly water
- intervertebral foramen- transmits nerve roots and radicular artery
discuss the age changes in intervertebral discs
- decreased water content
- loss of elasticity
- becomes thin
- bone-bone friction
- osteophyte formation
effects of degenerated IVD
- IVD prolapse
- herniation
- compression of nerve roots
contents of vertebral canal
- spinal cord till L1/L2
- cauda equina below L1/L2
- meninges and epidural space
- internal vertebral venous plexus
- epidural fat
blood supply of spinal cord and vertebrae
- anterior spinal artery- by union of anterior and posterior spinal arteries(which are branches of the fourth part of the vertebral artery)
- 2 posterior spinal arteries- PICA- vertebral
- 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
venous drainage of the vertebral column
vertebrae drain into internal venous plexus which in turn drains into external venous plexus
spine abnormalities
- spina bifida- occulta, meningocele, meningomyelocele
- vertebral canal stenosis
- abnormal curvatures
discuss spina bifida occulta
- defect in the vertebral arch with absence of the spine
- defect is covered by skin and tuft of hair
- spinal cord and meninges are in place
- no manifestations( most patients don’t know they have it)
- commonly occurs in the lumbosacral region
Discuss lumbar cistern
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
Discuss the articulation between 2 vertebra.
- 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
Describe the typical vertebra.
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
Discuss the features of the typical vertebra. ( How to distinguish them basically)
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
