Autonomic nervous system

Question 1

What is the ANS?

Answer 1

Part of the PNS
Not under conscious control
Controls non-skeletal peripheral function

Question 2

What muscles are controlled by the ANS?

Answer 2

Cardiac
Smooth muscle
Internal organs
Skin

Question 3

What are the two branches of ANS?

Answer 3

Parasympathetic and Sympathetic

Question 4

What is the parasympathetic nervous system?

Answer 4

Rest and Digest

Routine maintenance

Question 5

What is the sympathetic nervous system?

Answer 5

Fight and Flight

Question 6

What are the effects of the ANS on your pupil?

Answer 6

P: Constriction
S: Dilation

Question 7

What are the effects of the ANS on your heart?

Answer 7

P: Lowers rate and contractility
S: Increases rate and contractility

Question 8

What are the effects of the ANS on your stomach?

Answer 8

P: Increases motility and secretion
S: Decreases motility and secretion

Question 9

Give an example where the PNS and SNS do not both have effects

Answer 9

Blood vessels- only SNS

Question 10

Outline what the ANS does?

Answer 10

React to sensory information received in the integrating centre

Question 11

Give an example of action of ANS

Answer 11

Sensory information relayed by baroreceptors determines PNS/ SNS control of heart rate

Question 12

Where fo visceral motor nuclei originate?

Answer 12

Hypothalamus

Question 13

What happens to the visceral motor neurones?

Answer 13

Project to the brainstem or the spinal cord where they synapse with autonomic neurones

Question 14

In general, what do autonomic neurones consist of?

Answer 14

Two neurones (pre and post ganglionic)
A  ganglion

Question 15

What is a ganglion?

Answer 15

A nerve cell cluster or group of nerve cell bodies

Question 16

What is the structure of neurones in the PaNS?

Answer 16

Long pre-ganglionic fibres
Ganglions close to (or embedded within effector tissues)
Short post-ganglionic fibres

Question 17

What is the structure of neurones in the SNS?

Answer 17

Short pre-ganglionic fibres
Ganglions close to original site of pre-ganglionic neurones
Long post-ganglionic fibres

Question 18

What is the exception to this structure?

Answer 18

Adrenal gland
One nerve (no pre and post)
Secreted hormone not neurotransmitter
Secreted into bloodstream not synapse

Question 19

From what is ACh released from?

Answer 19

All pre-ganglionic neurones

PNS post-ganglionic neurones

Question 20

From what is NA released from?

Answer 20

SNS post-ganglionic neurones

Question 21

What effect would a drop in blood pressure have on the ANS function?

Answer 21

Less baroreceptor firing
Loose PNS effects
SNS effects become dominant

Question 22

What effect would the smell of food have on the ANS function?

Answer 22

Preparation of GI

PNS becomes dominant

Question 23

What would exposure to bright sunlight have on ANS function?

Answer 23

Pupils constrict

Driven by PNS

Question 24

What is unusual about the lungs?

Answer 24

There are PNS nerves innervating the lung tissue

No sympathetic neurones innervating lung tissue

Question 25

How does SNS influence lung function?

Answer 25

Hormone

Question 26

What type of receptor would you want at an autonomic ganglia?

Answer 26

Ach Ion channel receptor

Question 27

What is the advantage of G-protein coupled receptors?

Answer 27

The cell has more control | Can modulate rather than only open and close

Question 28

What do muscarinic ACh receptors do?

Answer 28

Respond the Ach release from post-ganglionic PNS fibres

Question 29

What do adrenergic receptors do?

Answer 29

Respond to NA release from post-ganglionic SNS fibres of adrenaline via blood

Question 30

How are neurotransmitters produced?

Answer 30

Precursor enzymatically converted to neurotransmitter Packaged into vesicles Action potential causes Ca influx and exocytosis Neurotransmitter release Receptor activation Removal of neurotransmitter from synapse via uptake into pre-synaptic terminal or glial cell

Question 31

What is step 1 with ACh?

Answer 31

Choline and acetyl CoA | converted by acetyl transferase

Question 32

What is step 6 with ACh?

Answer 32

Degraded by acetylcholinesterase | Choline taken up into pre-synaptic terminal by choline uptake protein

Question 33

What is step 1 with NA?

Answer 33

Tyrosine to DOPA by tyrosine hydroxylase | DOPA to Dopamine by DOPA decarboxylase

Question 34

What is step 2 with NA?

Answer 34

Dopamine in vesicles with Dopamine beta hydroxylase produces NA