Autonomic Nervous System (1)

Question 1

What is the function of the autonomic nervous system?

Answer 1

• controls all involuntary functions

Question 2

What are the 2 divisions of the autonomic nervous system?

Answer 2

1) sympathetic

2) parasympathetic

Question 3

Where is the pre-ganglionic nerve found ?

Answer 3

CNS

Question 4

Where is the post ganglionic nerve found ?

Answer 4

PNS

Question 5

which ganglionic nerve is myelinated and which isint?

Answer 5

• the pre-ganglionic nerve is myelinated and the post ganglionic nerve is unmyleinated.

Question 6

What are a few differences between the parasympathetic nerves and the sympathetic nerves ?

Answer 6

1) parasympathetic nerves have a long myelinated preganglionic nerve whereas they sympathetic nervous system has a short myelinated preganglionic nerve.
2) parasympathetic NS have a short postganglionic nerve whereas the sympathetic nervous system have a long postganglionic nerve

Question 7

Name the two very important neurotransmitters

Answer 7

ACH

noradrenaline

Question 8

All pre-ganglionic neurones in the parasympathetic and sympathetic nervous system are…

Answer 8

Cholingeric ( use ACH as a neurotransmitter)

Question 9

What type of receptors are found on the target tissue in parasympathetic nervous system ?

Answer 9

Muscarinic ACH receptors ( G protein coupled receptors)

Question 10

How many types of Muscarinic receptors are there ?

Answer 10

5 types

Question 11

The majority of sympathetic post ganglionic neurones are….

Answer 11

Noradrenergic/adrenergic

Question 12

What are the two major classes of receptors that noradrenaline interacts with ?

Answer 12

A-adrenoreceptors
( can be subdivided into a1/a2)
- b-adrenoreceptors ( can be subdivided into b1/b2)

Question 13

What type of receptors are muscarinic ACH receptors?

Answer 13

G protein coupled

Question 14

What is an exemption to the idea that ‘ all sympathetic post ganglionic neurones are noradrenergic/adrenergic?

Answer 14

Those targeting effector tissue such as sweat glands or hair follicles - they have CHOLINGERIC post ganglionic neurones.

Question 15

There is also a third division of the autonomic nervous system, what is it called ?

Answer 15

Enteric nervous system

Question 16

What is the function of the enteric nervous system ?

Answer 16

• governs the GI tract

Question 17

What is another exemption to the idea that “ all sympathetic postganglionic neurones are adrenergic ?

Answer 17

• the adrenal glands?
• sympathetic post ganglionic neurones differentiate to form neurosecretory chromaffin cells. Chromaffin cells can be considered postganglionic sympathetic neurones that do NOT project into target tissue.
• instead , on sympathetic stimulation these cells release adrenaline into the blood stream.

Question 18

Parasympathetic release of ACH on M2 receptors causes what effect in the heart ( SA node and AV node)

Answer 18

• when ACH binds to M2 receptors in the AV node , this causes bradycardia
• when ACH binds to M2 receptors in the AV node it causes reduced cardiac conduction velocity

Question 19

During parasympathetic activation, When ACH binds to m3 receptors what are the results in the lungs , GI tract , GU tract and eye ?

Answer 19

Lungs : bronchial contraction

GI tract : increased mobility/secretion

GU tract : bladder contraction and relaxation

GU tract : penile erection

EYE: ciliary muscle and iris sphincter contraction

Glandular : increased sweat/salivary / lacrimal secretion ( m1/m3)

Question 20

Sympathetic release of noradrenaline causes ….

Answer 20

Heart : tachycardia (b1 receptors)

Bronchiolar / intestinal / uterine relaxation ( b2 receptors)

Radical muscle contraction in the eye ( a1 receptors)