Neuro - Autonomic Nervous System

Question 1

What is the autonomic nervous system?

Answer 1

Motor sub division of the peripheral nervous system, concerned with subconscious control of the body (homeostasis)

Question 2

What structures in the body are involved in the autonomic nervous system?

Answer 2

Cardiac muscle
Smooth muscle
Viscera
Skin

Question 3

What 2 pathways form the afferent arm of the PNS?

Answer 3

Somatic sensory

Visceral sensory

Question 4

What is the visceral motor?

Answer 4

Sub division of motor neurones, concerned with autonomic nervous system and contains sympathetic and parasympathetic arms.

Question 5

What is the parasympathetic usually involved with?

Answer 5

Rest and digest (routine maintenance)

Question 6

What is the sympathetic usually involved in?

Answer 6

Fight or flight (mobilisation and increases in metabolism)

Question 7

Where are the parasympathetic and sympathetic arms usually found?

Answer 7

Usually found together apart from some exceptions e.g. the lungs

Question 8

What is the parasympathetic effect on the heart?

Answer 8

Decreases heart rate and contractility

Question 9

What is the parasympathetic effect on the stomach?

Answer 9

Increases gastric juice secretion and motility

Question 10

What is the parasympathetic effect on the pupils?

Answer 10

Constriction

Question 11

What is the parasympathetic effect on the liver?

Answer 11

Increase in bile secretion

Question 12

What is the sympathetic effect on the heart?

Answer 12

Increase heart rate and contractility

Question 13

What is the sympathetic effect on the stomach?

Answer 13

Decrease gastric juice secretion and motility

Question 14

What is the sympathetic effect on the pupils?

Answer 14

Dilation

Question 15

What is the sympathetic effect on the liver?

Answer 15

Increased hepatic glucose output

Question 16

What controls the blood vessel tone - both vasoconstriction and vasodilation?

Answer 16

Sympathetic nervous system

Question 17

What is the baroreceptor response to normal blood pressure?

Answer 17

Parasympathetic nervous system is promoted and sympathetic is inhibited, to decrease (maintain) heart rate

Question 18

What happens to blood pressure when we stand up?

Answer 18

Blood pressure drops

Question 19

What happens to baroreceptors following a fall in blood pressure?

Answer 19

Decrease in firing

Question 20

What happens as a result of decreased baroreceptor firing?

Answer 20

Decreased parasympathetic activation/stimulation

Question 21

What happens if the parasympathetic stimulation decreases?

Answer 21

Disinhibition of the sympathetic nervous system

Question 22

What is the effect of the sympathetic nervous system on the heart?

Answer 22

Increase heart rate and contractility, to increase and correct the reduced blood pressure

Question 23

Where do visceral motor nuclei originate?

Answer 23

Hypothalamus

Question 24

Describe the course of autonomic nerves after they originate in the hypothalamus?

Answer 24

Continue down the brainstem and spinal cord, and eventually travel to their innervated tissue

Question 25

Generally, what are the 2 parts of an autonomic nerve?

Answer 25

Pre ganglionic | Post ganglionic

Question 26

What is a ganglion?

Answer 26

Cluster of nerve bodies

Question 27

Describe the pre-ganglionic fibres of the parasympathetic nervous system

Answer 27

Long

Question 28

Describe the post-ganglionic fibres of the parasympathetic nervous system

Answer 28

Short

Question 29

Where do pre ganglionic parasympathetic neurones travel to/synapse?

Answer 29

Travel far to their respective organ and synapse close to the tissue that they innervate

Question 30

Describe the pre-ganglionic fibres of the sympathetic nervous system

Answer 30

short

Question 31

Describe the post-ganglionic fibres of the sympathetic nervous system

Answer 31

Long

Question 32

Where do pre-ganglionic sympathetic neurones travel to/synapse?

Answer 32

Not very far - synapse in the sympathetic trunks close to the spinal cord

Question 33

Why is the sympathetic nervous system usually more controlled?

Answer 33

To allow for mass activation of the fight or flight response when in danger thus increasing chances of survival

Question 34

How is the sympathetic nervous system usually under tighter control?

Answer 34

Travel in sympathetic trunks which are close to the spinal cord and run parallel with it.

Question 35

What neurotransmitters and receptors are found at the preganglionic sympathetic synapses?

Answer 35

ACh | Nicotinic

Question 36

What neurotransmitters and receptor are found at the preganglionic parasympathetic synapses?

Answer 36

ACh | Nicotinic

Question 37

What neurotransmitters and receptor are found at the postganglionic sympathetic synapses?

Answer 37

Noradrenaline | Adrenergic

Question 38

What neurotransmitters and receptor are found at the postganglionic parasympathetic synapses?

Answer 38

ACh | Muscarinic

Question 39

Where is there only one sympathetic (pre-ganglionic) fibre found as opposed to 2?

Answer 39

Adrenal gland

Question 40

Where do post ganglionic fibres usually release neurotransmitters?

Answer 40

Into the tissue they innervate.

Question 41

Along with the enteric system, how does the body regulate itself when we smell food?

Answer 41

Parasympathetic stimulation whereby gastric juice secretion increases and the stomach becomes more motile, ready for digestion

Question 42

What happens when we are exposed to bright sunlight?

Answer 42

Parasympathetic stimulation whereby pupils constrict to reduce sunlight travelling through the pupil to the retina.

Question 43

Where in the viscera are sympathetic neurones not found?

Answer 43

Lungs

Question 44

How do we get bronchodilation in the lungs?

Answer 44

Hormonal control - adrenaline form the blood increases bronchodilation

Question 45

How would you describe the effect of the autonomic nervous system?

Answer 45

Involuntary

Question 46

What is the micturition reflex?

Answer 46

Sensory information in the bladder is relayed back to the CNS and the visceral motor then controls the release of urine.

Question 47

What muscle does the parasympathetic nervous system control?

Answer 47

Detrusor muscle

Question 48

What muscle does the sympathetic nervous system control?

Answer 48

Internal sphincter muscle

Question 49

What happens when pressure builds up in the bladder ie from urine?

Answer 49

The sympathetic arm is still in charge while pressure is building up, therefore the internal sphincter is contracting and holding urine.

Question 50

What happens when the bladder is full?

Answer 50

Sensory information is relayed to the brain and the parasympathetic arm is turned on, while the sympathetic arm is turned off. This means the internal sphincter relaxes and detrusor contracts to expel urine

Question 51

Why do we not urinate involuntarily if the micturition reflex is under autonomic control?

Answer 51

We still have somatic control - the external sphincter is under GSE control so we can urinate as and when we want to.

Question 52

What are nicotinic ACh receptors linked to?

Answer 52

Na+ channel

Question 53

Where is nicotinic ACh found?

Answer 53

All autonomic intermediate ganglia for fast propagation

Question 54

Where may we find slower muscarinic ACh receptors?

Answer 54

Parasympathetic post ganglionic synapses

Question 55

How is Acetylcholine synthesised?

Answer 55

Choline combines with acetyl CoA under acetyl transferase to form acetylcholine.

Question 56

How is acetylcholine broken down/taken back up?

Answer 56

Broken down to choline and Acetyl via acetylcholinesterase. Choline is take back into pre-synapse via choline re uptake protein.

Question 57

How can we use acetylcholinesterase to treat Alzheimer's?

Answer 57

AChE can be blocked to allow for a build up of ACh which therefore can have a powerful therapeutic effect.

Question 58

What is step 1 of noradrenaline synthesis?

Answer 58

Tyrosine is converted to DOPA via tyrosine hydroxylase

Question 59

What is step 2 of noradrenaline synthesis?

Answer 59

DOPA is converted to Dopamine via DOPA decarboxylase

Question 60

What is step 3 of noradrenaline synthesis?

Answer 60

Dopamine is converted to noradrenaline via Beta-hydroxylase in vesicles

Question 61

How is noradrenaline taken back up into the presynapse?

Answer 61

Via MOA-O (pre-synaptic cell) or COMT (glial cell)

Question 62

How do we get adrenaline from noradrenaline?

Answer 62

Via phenylethanol methyl transferase