Autonomic Nervous System

Question 1

General facts about the autonomic nervous system

Answer 1

Sub division of the peripheral nervous system

Not under conscious control

Question 2

Examples of things controlled by the autonomic nervous system

Answer 2

Cardiac muscle ( heart)
Smooth muscle
Internal organs
Skin

Question 3

Somatic sensory

Answer 3

Responds to external sensory

Question 4

Visceral sensory

Answer 4

Controls internal environment

Question 5

What does the autonomic nervous system consist of

Answer 5

Sympathetic and parasympathetic branches of the visceral motor system

Question 6

Which horn does sensory information enter the spinal cord through

Answer 6

Dorsal horn

Question 7

Where does motor information leave the spinal cord through

Answer 7

Ventral horn

Question 8

What does the parasympathetic nervous system do

Answer 8

Routine maintenance ( ‘rest and digest’)

Question 9

What does the sympathetic response do

Answer 9

‘Fight and flight’ response

Question 10

Effect parasympathetic nervous system has on pupil

Answer 10

Constricts

Question 11

Effect sympathetic nervous system has on pupil

Answer 11

Dilation as during fight or flight you want to be receiving as much sensory info as possible so dilate the pupil

Question 12

What does Parasympathetic/Sympathetic do on heart

Answer 12

Parasympathetic; decreases rate and contraction to

Sympathetic; increases rate and comtractility

Question 13

What does parasympathetic and sympathetic do on stomach

Answer 13

Parasympathetic : increased motility and secretion

Sympathetic ; decreased motility and secretions

Question 14

What does parasympathetic / sympathetic do on lungs

Answer 14

Sympathetic : dilation , during fight or flight more O2 is needed
Parasympathetic; constriction

Question 15

What does parasympathetic / sympathetic do on liver

Answer 15

Parasympathetic; increased bile release

Sympathetic; increased glucose release - fight or flight so need more glucose

Question 16

What does parasympathetic/sympathetic do on bladder

Answer 16

Parasympathetic; contraction of bladder and stimulate bladder emptying
Sympathetic; relaxation

Question 17

Baroreceptors and blood pressure

Answer 17

Baroreceptor firing rate is directly proportional to pressure.
Increase in blood pressure-> increase in baroreceptor firing rate

Question 18

High blood pressure

Answer 18

Parasympathetic is switched on and decreases BP, heart rate is controlled and doesn’t go higher, sympathetic is switched off as you don’t want the BP to increase and go higher.

Question 19

Low Blood pressure

Answer 19

Baroreceptor firing rate decreases, so stimulus to inhibit sympathetic nervous system decreases, and the sympathetic nervous system is turned on

Question 20

Where do visceral motor nuclei originate and the what path do they follow

Answer 20

Originate in the hypothalamus and these visceral motor neurone project to the brain stem or the spinal cor where they synapse with autonomic neurone ( parasympathetic or sympathetic)

Question 21

Pre and post ganglionic neurones in the Parasympathetic NS

Answer 21

Long preganglionic fibres
Ganglions are close to / embedded within the effector tissues
Short post ganglionic fibres

Question 22

Pre and post ganglionic neurones in the Sympathetic nervous system

Answer 22

Short pre ganglionic fibres
Ganglions close to spinal cord
Long post ganglionic fibres

Question 23

Advantage of having a short pre ganglionic fibres in the sympathetic nervous system

Answer 23

Normally lots of sympathetic nerves in sympathetic trunks which are long and run parallel to spinal cord- allows for mass activation of neurones. So if you want an increased heart rate at same time as lung dilates

Question 24

Exception to two neurone arrangement in ANS

Answer 24

Adrenal gland - only have sympathetic nerve that innervates the adrenal gland - basically pre ganglionic fibre

Question 25

Neurotransmitters released at both synapses of parasympathetic nerve

Answer 25

Acetylcholine from presynaptic and postsynaptic ganglion

Question 26

Neurotransmitter release at ore ganglion

Answer 26

ACh

Question 27

Neurotransmitter released at post ganglionic fibre

Answer 27

Noradrenaline

Question 28

What is released at sympathetic nerve of adrenal gland

Answer 28

Adrenal gland secretes a hormone not a transmitter. Adrenaline ( and some noradrenaline) , and a bit of dopamine is released into bloodstream not synapse as only one ganglion

Question 29

What effect would the smell of food have on the gut

Answer 29

Parasympathetic’rest and digest’ would be activated and would tell stomach to start contracting and producing secretions .

Question 30

What is the enteric nervous system

Answer 30

Control system in gut which can occur independently of brain . The autonomic nervous system is the central control

Question 31

How does the sympathetic nervous system affect the lung function

Answer 31

There are no sympathetic neurones innervating the lung tissue. There are only parasympathetic . So adrenal glands release adrenaline which passes into blood into lungs and causes bronchodilation as neurotransmitter can’t be used

Question 32

Micturition reflex

Answer 32

Sensory information received within the bladder is that the pressure within the bladder is high and so the bladder slowly fills with urine. Info goes to the brain and down the NS again. You don’t want the bladder to contract until full so moderate pressure in bladder actually leads to internal sphincter being in change and contracted and so bladder closes ( SYMPATHETIC IN CHARGE) Once pressure gets to full the detrusor muscle contracts and the PARASYMPATHETIC SYSTEM IS IN CHARGE

Question 33

What type of receptor would be at an autonomic pre ganglionic fibre and adrenal gland

Answer 33

Ion channel receptor - nicotinic acetylcholine receptor

Question 34

What receptor mediates the response from neurotransmitter released from post ganglionic fibre

Answer 34

Muscarinic or adrenegric fibres ( G protein coupled receptor - slow response )

Question 35

Type of receptor in post ganglionic fibre in parasympathetic

Answer 35

Muscarinic

Question 36

What type of receptor would be in post ganglionic fibre in sympathetic system

Answer 36

Adrenergic

Question 37

Biosynthesis and metabolism of acetylcholine in synapses

Answer 37

1) choline and acetyl CoA enzymatically converted by choline acetyl transferase 2) packages into vesicles 3) AP , Ca influx, exocytosis 4) transmitter release 5) receptor activation ( muscarinic or nicotinic ) 6) ACh rapidly degraded by acetylcholinesterase in synapse. Choline taken up into presynaptic terminal by choline uptake protein

Question 38

What would happen if you block acetylcholinesterase

Answer 38

The ACh would accumulate in neurone and so you would have a much more powerful ACh response

Question 39

Biosynthesis and metabolism of noradrenaline

Answer 39

1) tyrosine converted to DOPA by tyrosine hydroxylase . DOPA converted to dopamine by DOPA decarboxylase 2) dopamine is packaged into vesicles with dopamine b hydroxylase . Produces noradrenaline, 3) stuff happens 5 ) adrenergic receptor is activated. 6) removal of neurotransmitter from synapse via uptake into pre- synaptic terminal or glial cell..

Question 40

What two enzymes break down noradrenaline

Answer 40

Monoamine oxidase in pre synaptic terminal | Ciatachole O methyl transferase in Glial cell ( COMT)

Question 41

Biosynthesis and metabolism of adrenaline

Answer 41

1) tyrosine converted to DOpA by tyrosine hydroxylase DOPA converted to dopamine by DOPA decarboxylase 2) Dopamine packaged into vesicles with dopamine B hydroxylase . Noradrenaline is the product 3) noradrenaline coverted to adrenaline in the cytoplasm by phenylethanol methyl transferase in adrenal gland 4) action potential causes calcium influx and exocytosis 5) exocytosis and neurotransmitter release 6) adrenaline diffuses into capillary and is transported to tissues in blood

Question 42

Where do the sympathetic nerves exit the spinal cord from

Answer 42

From T1 to L2 or L3

Question 43

Where does the parasympathetic nerves exit the spinal cord from

Answer 43

Emerges from cranial outflow in cranial nerves 3 , 7 , 9 and 10 or from the sacral outflow

Question 44

Which organ does not have direct sympathetic innervation

Answer 44

Lungs- goes via adrenal gland and then release of adrenaline

Question 45

Which organ does not have direct parasympathetic innervation

Answer 45

Adrenal gland