1a Autonomic Nervous System

Question 1

What is the autonomic nervous system (ANS) a subdivision of?

Answer 1

The peripheral nervous system

Question 2

What non-skeletal peripheral functions does the ANS control?

Answer 2

Cardiac muscle
Smooth muscle
Internal organs
Skin

Question 3

What are the 2 afferent neurones of the sensory division, and which of these is part of the ANS?

Answer 3

Somatic sensory
Visceral sensory afferent (part of ANS)

Question 4

What sort of stimuli does the somatic sensory neurone deal with?

Answer 4

External sensory stimuli from the periphery
e.g. skeletal muscle responding to walking

Question 5

What sort of stimuli does the visceral sensory afferent neurone deal with?

Answer 5

Internal sensory stimuli

Question 6

What are the two divisions of the autonomic nervous system?

Answer 6

Parasympathetic and sympathetic

Question 7

What does parasympathetic nervous system deal with?

Answer 7

Rest and digest

Question 8

What does the sympathetic nervous system deal with?

Answer 8

Fight and flight

Question 9

What are the sympathetic and parasympathetic responses of the eye?

Answer 9

Parasympathetic: pupil constriction
Sympathetic: pupil dilation

Question 10

What are the sympathetic and parasympathetic responses of the heart?

Answer 10

Para: decreases heart rate and strength of contractions
Symp: increase heart rate and strength of contractions

Question 11

What are the sympathetic and parasympathetic responses of the stomach?

Answer 11

Para: increase secretions and motility to increase rate of digestion
Symp: decrease secretions and motility

Question 12

What are the sympathetic and parasympathetic responses of the lungs?

Answer 12

Symp: increase breathing rate by dilation
Para: decrease dilation

Question 13

What are the sympathetic and parasympathetic responses of the liver?

Answer 13

Sympathetic: increase glucose release
Para: increase bile release

Question 14

What are the sympathetic and parasympathetic responses of the bladder?

Answer 14

Sympathetic: relaxation
Para: contraction

Question 15

Is the control of blood vessels and vasculature under parasympathetic or sympathetic control?

Answer 15

Sympathetic

Question 16

Where do visceral motor nuclei originate?

Answer 16

Hypothalamus

Question 17

What do autonomic neurones consist of?

Answer 17

Pre-ganglionic and post-ganglionic neurones

Question 18

In parasympathetic neurones, is the pre-ganglionic fibre longer or shorter than the post-ganglionic fibres?

Answer 18

Longer

Question 19

In the sympathetic neurone, is the pre-ganglionic fibre longer or shorter than the post-ganglionic fibres?

Answer 19

Shorter

Question 20

What is the exception to the two neurone arrangement in the autonomic nervous system?

Answer 20

The adrenal gland - only has one sympathetic nerve

Question 21

Which synpase releases noradrenaline?

Answer 21

The sympathetic post-ganglionic fibres

Question 22

What does the adrenal gland secrete?

Answer 22

Adrenaline

Question 23

In parasympathetic neurones, what neurotransmitter is released from the pre and post-ganglionic nerve? and what receptor?

Answer 23

Pre-ganglionic: ACh using nicotinic
Post: ACh uring muscarinic

Question 24

In sympathetic neurones, what neurotransmitter is released from the pre and post-ganglionic nerve?

Answer 24

Pre: ACh using nicotinic receptors
Post: Noradrenaline using adrenergic receptors

Question 25

What are the three types of neurotransmitter receptors what what type are they?

Answer 25

Nicotinic receptors: ACh in pre-ganglionic fibres (both sympathetic and parasympathetic) Muscarinic receptors: ACh in post-ganglionic of parasympathetic Adrenergic receptors: Noradrenaline in post-ganglionic of sympathetic

Question 26

How is acetylcholine synthesized?

Answer 26

Choline + Acetyl CoA is enzymatically converted using Choline Acetyl transferase

Question 27

What enzyme degrades Acetylcholine?

Answer 27

Acetylcholinesterase

Question 28

How is noradrenaline synthesized?

Answer 28

Tyrosine → DOPA by tyrosine hydroxylase DOPA → dopamine using DOPA decarboxylase Dopamine → vesicles with dopamine B hydroxylase → noradrenaline

Question 29

How is adrenaline synthesized?

Answer 29

Tyrosine → DOPA using tyrosine hydroxylase DOPA → dopamine using DOPA decarboxylase Dopamine → noradrenaline using dopamine B hydroxylase Noradrenaline → adrenaline using phenylethanol methyl transferase

Question 30

If there is a high blood pressure, how is this information relayed to the relevant visceral motors and which of the PNS and SNS are switched on?

Answer 30

Baroreceptors detect increase in pressure Signal sent to PNS → CNS → PNS → visceral motors Parasympathetic switched on to reduce blood flow Sympathetic switched off to prevent further increase in blood flow

Question 31

How does the lungs dilate in accordance with the sympathetic response?

Answer 31

The adrenal gland releases adrenaline into the bloodstream which then diffuses to the lungs to stimulate bronchodilation

Question 32

Are there parasympathetic neurons in the lung?

Answer 32

Yes, they cause bronchoconstriction via ACh

Question 33

Are there sympathetic neurons in the lung?

Answer 33

No

Question 34

Describe how the micturition system prevents urination when the bladder is only half full

Answer 34

Increasing bladder pressure triggers sympathetic The internal sphincter contracts, preventing urination

Question 35

Describe how the micturination system allows urination when the bladder is full

Answer 35

High pressure in the bladder leads to the sympathetic control being switched off, and parasympathetic on Detrusor contracts and internal sphincter relaxes, allowing urine out

Question 36

Which of the sphincter and detrusor is under sympathetic control?

Answer 36

Sphincter

Question 37

What affect does the smell of food have?

Answer 37

Triggers the parasympathetic system, so the GI tract increases secretion to undergo digestion

Question 38

What is the name of the complex neural network within the gut?

Answer 38

Enteric system

Question 39

Which receptors mediate FAST excitatory and inhibitory transmission?

Answer 39

Ion channel receptors

Question 40

Where are the muscarinic G-coupled protein receptors found?

Answer 40

Post-ganglionic parasympathetic neurones

Question 41

Where are the adrenergic G-coupled protein receptors found?

Answer 41

Post-ganglionic sympathetic fibers

Question 42

In the heart, what are the muscarinic and adrenergic receptors responsible for respectively?

Answer 42

Muscarinic (para) = decrease rate of contractions Adrenergic (sym) = increase rate of contractions

Question 43

What happens if you block ACh-esterase?

Answer 43

ACh accumulates in synaptic cleft and there is a much more powerful ACh effect

Question 44

Describe the action of adrenaline in the nerve innervating the adrenal gland

Answer 44

Action potential causes Ca2+ influx Exocytosis occurs thus NT released Adrenaline diffuses into capillaries and is transported to tissues in the blood

Question 45

If you take an opioid, what will happen to your pupils and why?

Answer 45

Constrict Parasympathetic nervous system activated