PNS and ANS

Question 1

What are the posterior rami?

Answer 1

dorsal branch

posterior division of the spinal nerve

Question 2

What is the anterior ramus?

Answer 2

Ventral branch

anterior division of the spinal nerve

Question 3

What is a plexus?

Answer 3

Branching network of vessels/nerves

Question 4

What is a ganglion?

Answer 4

Nerve cell cluster / group of nerve bodies in ANS/sensory system

Question 5

What are afferents?

Answer 5

Input nerve fibres (receive sensory info) - dorsal

Question 6

What are efferents?

Answer 6

Output nerve fibres (motor supply) - ventral

Question 7

What is the dura?

Answer 7

Thick outer meningeal layer attached to skull

Question 8

What is the arachnoid?

Answer 8

Layer containing arachnoid spaces / BBB for exchange between blood and csf

Question 9

What is the pia?

Answer 9

protective layer directly over the brain - continues down spinal cord

Question 10

What are white ramus communications?

Answer 10

preganglionic sympathetic nerve tract fibres from spinal cord

Question 11

What are the grey ramus communications?

Answer 11

postganglionic nerve fibres for sympathetic tract

Question 12

What are intercostal nerves?

Answer 12

11 Spinal nerves emerging from vertebral column and run along with the ribs
1 subcostal runs under rib 12

Question 13

What does the vagus nerve innervate?

Answer 13

Vagus nerve (CNX)
parasympathetic innervation to thorax and abdomen

Question 14

What does the phrenic nerve innervate?

Answer 14

Phrenic nerve (C3,4,5)
supplies diaphragm - important for breathing

Question 15

What are the cervical and lumbar enlargements?

Answer 15

Attachment of large nerves supplying upper limb (C5-T1)

Question 16

What is the conus medullaris?

Answer 16

Where the spinal cord terminates at a tapering point

starts around L1/2

Question 17

What is the cauda equina?

Answer 17

Many dull, yellow coloured nerve roots (L2-L5)

- hangs like a horse tail ‘equina’

Question 18

What is the filum terminale?

Answer 18

A single white fibrous cord - anchors spinal cord

Question 19

What structure encases the spinal cord?

Answer 19

Spinal cord is enclosed within a tough fibrous dural sac
- spinal dura continuous with cranial dura at foramen
magnum

Question 20

What lines the dural sac?

Answer 20

Arachnoid - transparent membrane

Question 21

What is the denticulate ligament?

Answer 21

Serrated ligament found on either side of spinal cord between dorsal and ventral roots

Question 22

What is the role of the sympathetic chain?

Answer 22

Communicates with the spinal nerves via white and grey rami

- clearly seen in thoracic region

Question 23

Where are parasympathetic preganglionic fibres?

Answer 23

In brainstem (CN) or sacral region of spinal cord