Autonomic Nervous System

Question 1

What is the autonomic nervous system?

Answer 1

A sub division of the peripheral nervous system not under concious control

controls non skeletal peripheral function: cardiac muscle(heart), smooth muscle, internal organs, skin

Question 2

What part of the autonomic nervous system is the sympathetic a sub division of?

Answer 2

visceral motor

Question 3

Describe simply the parasympathetic and sympathetic nervous system?

Answer 3

Parasympathetic- rest and digest(normal body functions) sympathetic- fight or flight

Question 4

What is the effect of the parasympathetic and sympathetic on the pupils?

Answer 4

Sympathetic- dilate to give wider field of vision which will help in decision making

Question 5

What is the effect of the parasympathetic and sympathetic on the stomach?

Answer 5

Parasympathetic- more secretions to increased digestive rate sympathetic- less secretion preserve energy for movement

Question 6

What is the effect of Parasympathetic and sympathetic on the liver?

Answer 6

parasympathetic- bile release (helps aid the digestion of fats) sympathetic- glucose release

Question 7

What is the effect of the sympathetic and parasympathetic on the lungs?

Answer 7

parasympathetic-constriction

sympathetic- dilation of airways(more oxygen for respiration)

Question 8

What is the effect of the parasympathetic and sympathetic on Bladder?

Answer 8

parasympathetic- contract to help excrete

sympathetic- relax

Question 9

Do the parasympathetic and sympathetic always have opposing action?

Answer 9

No because sometimes you don’t always have a parasympathetic and sympathetic nerve going to the same organ/ tissue For example with blood vessels you mostly have sympathetic nerves going to them and these can both constrict and dilate the blood vessels

Question 10

Describe pathway to the brain and away from the brain?

Answer 10

You have the sensory division which includes the sensory and Visceral divisions This sends information to the PNS which goes to the CNS for processing CNS send info back to the PNS which sends info to the Motor division(efferent) Motor division is also split into the somatic and visceral subsections The visceral motor is split into the sympathetic and parasympathetic

Question 11

Where are baro recepors and waht do they do?

Which part of the ANS are they are part of?

Answer 11

Baroreceptors- in large arteries they sense blood pressure and send info to the brain constantly

Question 12

What happens if your blood pressure starts to rise?

Answer 12

Detected by baroreceptors which send the info to the brain which sends instructions to PNS -> motor division-> visceral motor->parasympatheic which slows down heart rate, at the same time the sympathetic nervous system is supressed

Question 13

Which part of the brain receives the information and determines the appropriate response ?

Answer 13

Hyper thalamus

Question 14

Where do visceral motor nuclei originate from?

Answer 14

In the hyperthalamus

Question 15

Where do visceral motor neurones go?

Answer 15

to the brainstem or spinal cord where they synapse with autonomic neurons

Question 16

What is a ganglion?

Answer 16

cluster of nerve cells

Question 17

what two neurons are key in the autonomic nervous system?

Answer 17

Pre-ganglionic and post- ganglionic neurons

Question 18

describe the pre and post ganglionic fibres for the parasympathetic nervous system?

Answer 18

Long pre ganglionic fibres which goes to ganglion (close to or embedded within effector tissue)

short post ganglionic neuron after which goes to effector organ

Question 19

describe pre and post ganglionic fibres of sympathetic nervous system?

Answer 19

short pre ganglionic fibres Ganglion is close to originateing site of the pre-ganglionic neuron

Long post ganglionic fibres going to effector organ

Question 20

why are the pre and post ganglionic fibres for the parasympathetic and sympathetic nervous system different?

Answer 20

Sympathetic nerves often work together to form very coordinated responses.

Lots of preganglionic fibres of Sympathetic synapse in the sympathetic trunk that runs next tot the spinal cord which allows for these coordinated responses

Question 21

What is the exception to the 2 neuron arrangement of the ANS?

Answer 21

Adrenal gland- just one nerve, no pre and post fibre

The adrenal gland almost behaves like the post ganglionic fibre and this is where hormones are released as oppose to neurotransmitters

Question 22

Which neurotransmitters are released at each autonomic synapse?

Answer 22

ACh released by pre ganglionic parasympathetic and sympathertic fibres

Ach released at para sympathetic post ganglionic fibres

Noradrenaline released at post ganglionic sympathetic fibres

Question 23

Why is the neurotransmitter from the post ganglionic neuron different for sympathetic and parasympathetic nervous system?

Answer 23

Same for the pre ganglionic neuron because you just need the signal to transmit for the neuron to the next but its different for the post because these go to the effector neuron so you want the response to be different which requires different neurotransmitters and different receptors

Question 24

What does the adrenal gland secrete and where?

Answer 24

secretes hormone into the bloodstream

Question 25

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

Answer 25

Detected, tells the brain that digestion will occur soon so it prepare GI tract and stomach. Parasympathetic effect becomes dominant

Question 26

What is the enteric nervous system?

Answer 26

Nick named ‘mini brain’ has a big influence on gut function in addition to the brain which kinda complicates things

Question 27

Which part of the ANS goes to the lungs?

Answer 27

Only parasympathetic nerves innervate lung tissue

Question 28

How does the sympathetic nervous system influence lung function?

Answer 28

Uses a hormone (adrenaline) instead of sympathetic nerve

Question 29

What is micturition reflex?

Answer 29

Parasympathetic nerve innervates the detrusor muscle which causes contraction

when pressure builds up in the bladder the sympathetic nerve innervates the internal sphincter which casues the bladder to relax

Question 30

What kind of receptor would you want at an autonomic ganaglia?

Answer 30

Nicotinic ACh receptor

One that mediates a really fast response so it can immediately transfer to post ganglionic neuron. This one is coupled with an ion channel which helps mediate fast excitatory and inhibitatory transmission.

Question 31

What kind of receptor receive info from the post ganglionic fibres?

Answer 31

Different receptors as parasympathetic use ACh neurotransmitter and sympathetic use Noradrenaline.

MUSCARINIC receptors respond to ACh from post ganglionic PNS fibres

ADRENERGIC receptors respond to Noradrenaline from post ganglionic SNS fibres

G- protein coupled receptor used for both types - these have a slower response they are more complicated in their signalling mechanism which gives the cell more control

Question 32

How are neurotransmitters produced?

Answer 32

something is delivered to nerve by blood stream and this precursor is enzymatically converted into a neurotransmitter in the pre-synaptic terminal

Question 33

How is ACh made?

Answer 33

Choline and acetyl CoA are enzymatically converted by ascetyl transferase into ACh

Question 34

How is noradrenaline made?

Answer 34

1- Tyrosine converted to DOPA by tyrosine hydrolase.

2-DOPA converted to dopamine by DOPA decarboxlase

3- dopamine is packaged into vesicles with dopamin beta hydroxylase enzyme and converts it into noradrenaline in the vesicles.

Question 35

How is adrenaline made? and what happens to it?

Answer 35

1- Tyrosine converted to DOPA by tyrosine hydrolase. DOPA converted to dopamine by DOPA decarboxlase

2- dopamine is packaged into vesicles with dopamin beta hydroxylase enzyme and converts it into noradrenaline in the vesicles

3- Noradenaline converted into adrenaline in the cytoplasm by phenylethanol methyl transferase

4-when the action potential causes ca2+ influx and exocytosis the neurotransmitter is released into the bloodstream and is transported to tissues to have effect (no metabolism and no need to remove from synapse)

Question 36

helps mediate fast excitary and inihWhat is the difference between mucarinic and nicotinc receptors?

Answer 36

Both bind to ACh

Mucarinic-coupled with a G-protein coupled receptors(slow response)

Nicotinic-coupled with ion channel(fast transmission of excitatory and inhibitory responses)

Question 37

What is the difference between somatic and viseral?

Answer 37

-both have sensory and motor part

Somatic-innervate skeletal muscle

Viseral-innervates cardiac and smooth muscle, skin and organs