Lab 2a- Spinal Cord

Question 1

What is continuous at the level of the foramen magnum (hole at base of skull)

Answer 1

spinal cord and brainstem

Question 2

whats the difference between the meninges in brain and spinal cord

Answer 2

Dura mater in brain has 2 layers- outer periosteal layer and inner meningeal layer. The outer periosteal layer is attached to the skull

Dura mater in spinal cord has 1 layer- inner meningeal layer and is not directly attached to the spinal vertebrae. The epidural space between the dura and spinal vertebrae exists- has fat and veins in that space

Question 3

what are dorsal root ganglion and what do they contain

Answer 3

Each dorsal root has a swelling- dorsal root ganglion

Contains cell bodies of primary afferent fibres (sensory)

Question 4

what meningeal layer do the dorsal and ventral root lie in

Answer 4

subarachnoid space

Question 5

what are spinal nerves a fusion of

Answer 5

dorsal and ventral roots fuse to form spinal nerves

Question 6

Laterally, dura mater merges with which connective tissue sheath and what does it cover

Answer 6

Epineurium which covers the emerging spinal nerve

Question 7

Describe the cross section of spinal cord

Answer 7

• Central H shaped area of grey matter, this area is surrounded by white matter
• White matter has axons and divided into dorsal, ventral and lateral white COLUMNS.
  (dorsal is superior, lateral is in the middle and ventral is inferior)
• Grey matter has dorsal HORN, intermediate grey area and ventral HORN
• Grey matter contains the cell bodies and dendrites of nerve cells.

Question 8

what is the function of myelin

Answer 8

allows electrical impulses to transmit quickly along nerve cells

Question 9

How does the arrangement of grey and white matter in spinal cord differ from that in the brain

Answer 9

White matter is buried deep in the brain, while grey matter is mostly found on the brain’s cortex. The spinal cord, has the opposite arrangement: grey matter at its core with insulating white matter on the outside

Question 10

The spinal cord is much larger in CERVICAL and LUMBAR regions compared to thoracic and sacral. why is that

Answer 10

Cervical- provides nerve supply to upper limb

Lumbar- provides nerve supply to lower limbs

Question 11

describe the variations in grey matter in spinal cord segments

Answer 11

Grey matter has ventral horn and dorsal horn.
ventral horn contains motor neurons supplying muscles and limbs have most of that so ventral horn larger in CERVICAL and LUMBAR
same reason for dorsal horn and so dorsal horn is largest in both these regions as well