Spinal Cord and ANS

Question 1

Where in the vertebral column does the spinal cord end in adults vs foetus?

Answer 1

12 week foetus - all the way
Adult - L1-2

Question 2

What is the name of the lower end of the spinal cord?

Answer 2

Conus medullaris

Question 3

What is the name of the bundle of nerve roots that continues from the spinal cord?

Answer 3

Cauda Equina

Question 4

What is the name of the continuation of Pia mater down the caudal equina?

Answer 4

Filum terminale

Question 5

What is the filum terminal externa?

Answer 5

Part of filum terminale that extends down the coccygeal

Question 6

What is the lumbar cistern?

Answer 6

extension of subarachnoid space in the dural sac in the cauda equina

Question 7

Dural cistern

Answer 7

Ends at s2 and has CSF inside. attaches to filum terminale externum

Question 8

Nissl bodies

Answer 8

Found within somas and dendrites, containing rough endoplasmic reticulum (produces protein)

Question 9

Where do spinal nerves exit the vertebral column?

Answer 9

Intervertebral foramen

Question 10

Which nerves supply the brachial plexus?

Answer 10

C5 - T1, upper limbs

Question 11

Which nerves supply the lumbosacral plexus and what does this innervate?

Answer 11

L1-S4, lower limbs

Question 12

Dorsal root vs Dorsal rami

Answer 12

Dorsal root supplies sensory neurones, while dorsal rami supplies both sensory and motor neurones

Question 13

Ventral rami vs Ventral root

Answer 13

Ventral rami - Sensory and motor innervation. Ventral root - motor nerves

Question 14

Ventral rami vs dorsal rami

Answer 14

Ventral supplies anterior trunk and limbs
Dorsal supplies posterior back

Question 15

What nerves innervate sympathetic outflow?

Answer 15

T1-L2/3

Question 16

What is ischemia?

Answer 16

Deficiency of blood to the spinal cord can lead to ischemia

Question 17

How can spinal cord injuries come about?

Answer 17

Blunt trauma, e.g. spinal cord compression from a slipped disc, leading to pinched nerves and complete/partial loss of function/sensation

Question 18

What relevance do lumbar punctures have?

Answer 18

Clinically, we take punctures at L3-4 (after spinal cord) to give anaesthesia in the spine (c-section) or epidural (minor surgery)

Question 19

Where is the lateral horn present and what is it?

Answer 19

From T1 - L2/3 and (s2-4) neurones cell bodies and holds sympathetic

Question 20

What does the sympathetic chain allow?

Answer 20

All 31 nerves have sympathetic outflow - but nerves are only present in thoracolumbar regions. Allows nerves to travel up of down the chain to supply other nerves

Question 21

What are splanchnic nerves?

Answer 21

Ones which don’t synapse in the sympathetic chain. They synapse after and supply abdominal organs

Question 22

What are the 3 options for sympathetic fibres from the lateral horn?

Answer 22

1 - synapse in same position on the chain
2 - synapse up or down the sympathetic chain
3 - don’t synapse in the chain - synapse later (splanchnic nerves)

Question 23

How does the face receive sympathetic nerve supply?

Answer 23

Sympathetic fibres travel up sympathetic chain and synapse at C1, C6 or C8. nerve fibre then travels up blood vessels to get to the face