8.1 ANS

Question 1

What is the autonomic nervous system responsible for?

Answer 1

Part of nervous system
Controls all involuntary functions
Seperated from Somatic (voluntary) motor system

Question 2

What are the two anatomically defined divisions of the autonomic nervous system?

Answer 2

1. Sympathetic
   - responds to stressful situations ‘fight or flight’
   - increased heart rate, force of contraction and bp
2. Parasympathetic
   - ‘rest and digest’
   - regulates basal activities e.g. Heart rate

Both oppose each other

Question 3

General structure of ANS.

Answer 3

1. Parasympathetic
   - myelinated, long pre-ganglionic nerve
   - unmyelinated, short post-ganglionic nerve to innervated tissue
2. Sympathetic
   - myelinated, short pre-ganglionic nerve
   - unmyelinated, long post-ganglionic nerve

Question 4

All preganglionic nerves are ______________?

Answer 4

Cholinergic (ACh, nAChR)

Question 5

Parasympathetic postganglionic neurones are ________________?

Answer 5

Cholinergic (ACh, mAChR)

Question 6

MOST Sympathetic postganglionic nerves are ________________?

Some are ________?

Answer 6

Noradrenergic (NA, a1,a2-adrenoreceptors or b1,b2,b3-adrenoreceptors)

Cholinergic (sweat glands, hair follicles)

Question 7

Describe adrenal glands within the ANS.

Answer 7

• sympathetic post-ganglionic neurones in adrenal glands are different - they’re neuroendocrine cells which differentiate to form neurosecretory chromaffin cells
• innervated by pre-ganglionic sympathetic neurons
• chromaffin cells considered as post ganglionic neurones that do not project to a target tissue

Question 8

What is an umbrella term for ANS disorders?

Answer 8

Dysautonomia