W3 - Peripheral NS

Question 1

What are the divisions of the PNS and what are the divisions of these?

Answer 1

Sensory (afferent) - Somatic + visceral, Motor (efferent) - Somatic + autonomic (symp/parasymp)

Question 2

What division of the PNS does taste/smell and hearing/vision come under?

Answer 2

Taste/smell - visceral sensory, Hearing/vision - somatic sensory

Question 3

What motor division does innervation of all skeletal muscles come under?

Answer 3

Somatic motor

Question 4

What motor division does innervation of the cardiac muscles come under?

Answer 4

Autonomic motor (symp/para)

Question 5

What root from SC, dorsal/ventral, has sensory or motor neurons?

Answer 5

Dorsal root - sensory, Ventral root - motor

Question 6

What is in the dorsal root ganglion and ventral horn?

Answer 6

DRG - sensory cell bodies, Ventral horn in SC - motor cell bodies

Question 7

What is a ganglion?

Answer 7

A cluster of many nerve cell bodies

Question 8

What does a spinal nerve consist of and what is a ramus?

Answer 8

Spinal nerve has mixed sensory + motor neurons and ramus are branches of the spinal nerves

Question 9

What is the function of the fat layer within the meninges and where do nerve roots leave the spine to form spinal nerves?

Answer 9

Protection/cushioning, leave spine through intervertebral foramen (weakest place in spine)

Question 10

There are 31 pairs of spinal nerves, where do they supply (+not)?

Answer 10

All of body but not head

Question 11

How many cervical, thoracic, lumbar, sacral and coccygeal spinal nerves?

Answer 11

C - 8, T - 12, L - 5, S - 5, C - 1

Question 12

Where do peripheral nerves originate?

Answer 12

CErvical region or sacral region

Question 13

What do you call a single major intercostal nerve from a single spinal nerve?

Answer 13

The trunk

Question 14

During development, plexi become mor comlpex, what is a nerve plexus? (e.g. brachial plexus)

Answer 14

An interwoven network of nerve fibres

Question 15

Where do ramus communicans branch from?

Answer 15

T1-12 then L1-3

Question 16

Ramus communicans connect to sympathetic chains either side of the spine, what is a symp chain?

Answer 16

Linked sympathetic ganglia

Question 17

What do you can an area of skin which is innervated by sensory axons of a single spinal nerve?

Answer 17

Dermatome

Question 18

The spinal nerves dont always line up with/innervate the territory of the spinal levels in which they arise (think dermatomes), ture or false?

Answer 18

True

Question 19

What do you call the continuations of the dura, arachnoid and pia mater that surround nerves?

Answer 19

Dura - epineurium, Arach - perineurium, Pia - endoneurium

Question 20

Do nerve coverings surround only one nerve?

Answer 20

No may be one nerve but can be bundles of many nevres

Question 21

What is the function of the epineurium, perineurium and endoneurium?

Answer 21

Epi - Provides strength, Peri -, Endo -

Question 22

Schwann cells maintain the environment (pH/glucose), do all neurons need them?

Answer 22

Yes

Question 23

Why are the two reasons a larger diameter fibre conduct APs faster?

Answer 23

Less organelles in the way, more myelin allowing for saltatory conduction

Question 24

The perineurium surrounds fascicles, what do the perineurial cells have to form a barrier between nerves and external environment?

Answer 24

Tight junctions