Peripheral Nervous System

Question 1

Diff nerves
vs function

Answer 1

Spinal Nerves

Cranial Nerves

Somatic NS vs Autonomic NS

Question 2

Somatic NS

Answer 2

Recieves info from skeletal muscle (striped), visceral organs and receptors in the skin and controls skeletal muscles.

Question 3

Autonomic/Visceral

Answer 3

Controls involuntary function of inner organs. Divided into parasympathetic and sympathetic and Enteric NS (intestines).

Question 4

Peripheral Nerves

Answer 4

Bundles of nerve fibres, may be myelinated.
Multiple layers of connective tissue with high blood supply.
Well protected and mechanical strength and support. Mixture of fibres and neurons.

Question 5

Cranial Nerves

Answer 5

Learn Mnemonic

Question 6

Dermatomes

Answer 6

Each somatic spinal nerve root innervates one area of skin, a dermatome.
A motor nerve innervates multiple muscles (myotome).

Question 7

Visceral Cranial Nerves

Answer 7

Oculomotor - parasympathetic control of lens and pupil.

Glossopharygneal -

Question 8

Para and sympathetic

Answer 8

Both regulated by hypothalamus and hindbrain nuclei.
Always 2 neurons (pre ganlglionic and post)
In sympathetic NS the ganglia form a chain.
No cranial nerves in Sympathetic.
Para from cranial and sacral.

Question 9

Sympathetic function

Answer 9

Fight or flight
Promotes increase of HR, skin blood vessel constriction, slows gut activity. Stimulates release of adrenalin/noradrenalin.

Question 10

Output neurons and system

Answer 10

Output neurons from spinal chord are short and enter sympathetic ganglia.
Synapse into large network of ganglionic neurones. Synchronised activity.

Question 11

Parasympathetic function