Lecture 6

Question 1

spinal cord

Answer 1

continuation of the brainstem, extends from foramen magnum at the base of the skull to the L1/L2 vertebrae

Question 2

verterbrae arranged in 5 regions

Answer 2

• 7 cervical
• 12 thoracic
• 5 lumbar
• 5 sacrum
• 4 coccyx
• sacrum and coccyx fused together

Question 3

atlas

Answer 3

first vertebra of the cervical region b/w base of the skull & C2 ( axis )

Question 4

axis

Answer 4

second vertebra of cervical region b/w atlas ( C1 ) & C3

Question 5

function of atlas and axis

Answer 5

• support the head on the lower cervical spine providing for mobility in extension, rotation, flexion
• specialised to allower a greater range of motion than other vertebrae

Question 6

comparison of vertebrae

Answer 6

look at notes lol

Question 7

spinous processes

Answer 7

bony projections off the posterior of each vertebrae
* provides a point of attachment for muscles and ligaments of the spine

Question 8

vertebral foramen

Answer 8

bony hollow opening of vertebrae through which all spinal nerve roots run

Question 9

SC anatomy

Answer 9

• begins at the occipital bone
• ends as cauda equina
• provides 2-way communication b/w CNS & PNS

Question 10

Cervical enlargement

Answer 10

• SC expansion corresponds to arms
• C4 - T1, max circumference 38mm
• nerves serving arms emerge here

Question 11

Lumbar enlargement

Answer 11

• SC expansion corresponding to lower limbs
• T11 - L2 , max circumference 33mm
• nerves serving lower limbs emerge here

Question 12

cauda equina

Answer 12

collection of nerve roots at the inferior end of the vertebral canal wall

Question 13

cauda equina syndrome symptoms

Answer 13

• low back pain, radiating down the legs
• numbness around anus
• loss of bladder/bowel control

Question 14

cauda equina syndrome causes

Answer 14

• compression
• spinal stenosis ( narrowing )
• disc herniation
• abscess formation

Question 15

SC internal anatomy

Answer 15

• grey matter inside, white matter outside
• 2 lenghth wise grooves that divide cord into left and right
  1. ventral ( anterior ) median fissure
  2. dorsal ( posterior ) median sulcus
• gray comissure connects left & right grey areas

Question 16

Grey matter

Answer 16

• has large number of neurons present, allows it to process info
• has 4 main columns
  1. dorsal horn - contains interneurons; receives somatosensory info from body to brain
  2. ventral horn -motor neurons that exit SC to innervate skeletal muscle
  3. intermediate & lateral horn - lateral responsible for regulating ANS

Question 17

spinal nerves

Answer 17

• pass in and out superior to the corresponding vertebrae via intervertebral foramen
• supply all areas of the body except head & neck regions ( cranial nerves )

Question 18

31 pairs of spinal nerves

Answer 18

• 8 cervical nerves
• 12 thoracic nerves
• 5 lumbar nerves
• 5 saccral nerves
• 1 coccygeal nerve

Question 19

white matter

Answer 19

• contains bundles of nerve axons
• allows communication with CNS
• may be ascending or descending

Question 20

descending pathways

Answer 20

deliver efferent impulses from brain to spinal cord

Question 21

direct pathways - pyramidal tracts

Answer 21

• originate in motor cortex
• carry motor fibres to SC & brainstem
• responsible for volitional movements
• parkison’s disease

Question 22

indirect pathways - extrapyramidal tracts

Answer 22

• originate in brain stem
• motor fibres to SC
• prevent unwanted movements
• huntington’s disease
• responsible for autonomic control of balance, posture

Question 23

incomplete injuries

Answer 23

• central cord syndrome
• posterior cord syndrome
• anterior cord syndrome
• cauda equina syndrome

Question 24

quadriplega

Answer 24

• injury in cervical region
• all 4 extremities are affected

Question 25

paraplegia

Answer 25

• injury in lumbar, thoracic or saccral regions
• only 2 extremities affected

Question 26

causes of SC injury

Answer 26

• assault
• sport
• tumours
• infection
• falls
• central cord syndrome