Lecture 14 + 15: ANS

Question 1

What is the general function of the ANS?

Answer 1

Control all involuntary functions

Question 2

What are the 2 divisions of ANS?

Answer 2

Parasympathetic and sympathetic

Question 3

What does the sympathetic nervous system do?

Answer 3

In stressful situations, activates flight or fight response

Question 4

What does the parasympathetic nervous system do?

Answer 4

Regulate basal activities - rest and digest

Question 5

What are the 5 anatomical divisions of the brain stem and spinal cord?

Answer 5

Medullary 
Cranial 
Thoracic
Lumbar 
Sacral

Question 6

Which anatomical divisions is the sympathetic nervous system linked to?

Answer 6

Thoracic and lumbar

Question 7

Which anatomical divisions of the spinal cord is the parasympathetic system linked to?

Answer 7

Medullary

Sacral

Question 8

Where does parasympathetic nerves originate in?

Answer 8

Lateral horn of medulla and sacral spinal cord

Question 9

Where do sympathetic nerves originate in?

Answer 9

Lateral horn of lumbar and thoracic spinal cord

Question 10

Describe the parasympathetic preganglionic fibers.

Answer 10

Long myelinated preganglionic fibers

Question 11

Describe the parasympathetic postganglionic fibers.

Answer 11

Short unmyelinated postganglionic fibres

Question 12

Describe the sympathetic preganglionic fibers.

Answer 12

Short myelinated preganglionic fibers

Question 13

Describe the sympathetic postganglionic fibers.

Answer 13

Long unmyelinated postganglionic fibers

Question 14

Where is the parasympathetic ganglia located?

Answer 14

Within innervated tissues

Question 15

Where is the sympathetic ganglia located?

Answer 15

In paravertebral chain close to spinal cord

Question 16

What are the 2 principle neurotransmitters in the ANS?

Answer 16

Acetylcholine

Noradrenaline

Question 17

What neurotransmitter do parasympathetic and sympathetic pre ganglionic neurons use?

Answer 17

Ach

Question 18

What kind of receptor is nicotinic Ach receptors?

Answer 18

Ligand gated ion channels

Question 19

What neurotransmitter do parasympathetic post ganglionic neurons use?

Answer 19

Ach

Question 20

What kind of receptors are post ganglionic receptors?

Answer 20

Nicotinic Ach receptors

Question 21

What do parasympathetic post-ganglionic neurons release?

Answer 21

Ach

Question 22

What kind of receptors are in the target tissue linked to parasympathetic system?

Answer 22

Muscarinic Ach receptors

Question 23

What kind of receptors are muscarinic ACh receptors?

Answer 23

GPCRS

Question 24

What neurotransmitters do most sympathetic post-ganglionic neurons use?

Answer 24

Noradrenaline

Question 25

What does noradrenaline interact with?

Answer 25

Adrenoceptors

Question 26

What kind of receptors are adrenoceptors?

Answer 26

GPCR

Question 27

What neurotransmitter do some (less than majority) sympathetic post-ganglionic neurons use?

Answer 27

Ach

Question 28

What other kinds of transmitters are found in the ANS?

Answer 28

Non-adrenergic, noncholinergic transmittrs

Question 29

What are 2 non-adrenergic, non-cholinergic transmitters?

Answer 29

``` ATP Nitric acid (NO) ```

Question 30

What do sympathetic postganglionic neurons in the adrenal glands differentiate to form?

Answer 30

Neurosecretory chromaffin cells

Question 31

How do chromaffin cells work?

Answer 31

Upon sympathetic stimulation, they release adrenaline into the blood stream instead of projecting to a target tissue

Question 32

What are 3 types of tissues that parasympathetic release of Ach would affect?

Answer 32

Heart Smooth muscle Glandular

Question 33

What are 2 effects of parasympathetic stimulation on the heart?

Answer 33

Bradycardia (slowing of heart rate) | Reduced cardiac conduction velocity

Question 34

What are 5 effects of parasympathetic stimulation on smooth muscle?

Answer 34

1. Bronchial contraction of airways 2. Increased intestinal mobility or secretion 3. Bladder contraction and relaxation 4. Penile erection 5. Ciliary muscle and iris sphincter contraction

Question 35

What is the effect of parasympathetic stimulation on glandular tissues?

Answer 35

Increased sweat, salivary, lacrimal secretions

Question 36

What are 4 types of tissue that sympathetic stimulation would affect?

Answer 36

Heart Smooth muscle Glandular Kidney

Question 37

What are 2 effects of sympathetic stimulation on the heart?

Answer 37

Tachycardia - increased speed | Positive inotropy - increased force of contraction

Question 38

What are the 4 effects of sympathetic stimulation on smooth muscle?

Answer 38

Arteriolar and venous contraction Bronchiolar intestinal and uterine relaxation Bladder sphincter contraction Radial eye contraction

Question 39

What is the effect of sympathetic stimulation on glands?

Answer 39

Increased salivary secretion

Question 40

What is the effect of sympathetic stimulation on kidney?

Answer 40

Renin release

Question 41

What are the 4 common sites of drug action during neurotransmission?

Answer 41

1. Degradation of transmitter 2. Interaction with post-synaptic receptors 3. Inactivation of transmitter 4. Re-uptake of transmitter 5. Interaction with pre-synaptic receptors

Question 42

How is acetylcholine synthesised?

Answer 42

Acetyl CoA + choline makes acetylcholine using choline acetyltransferase (CAT)

Question 43

How is acetylcholine degraded?

Answer 43

Acetylcholine is degraded by acetylcholinesterase into acetate and choline

Question 44

What are 2 potential therapeutic interventions of cholinergic transmission?

Answer 44

1. Ganglion-blocking drug | 2. Acetylcholinesterase inhibitors

Question 45

What is an example of a ganglion blocking drug?

Answer 45

Trimethaphan used in hypertensive emergencies to produce controlled hypotension during surgery

Question 46

What are 2 examples of AchE inhibitors and what do they treat?

Answer 46

Pyridostigmine treats myasthenia gravis Donepezil treats Alzheimer’s Enhance actions of endogenous of released AcH

Question 47

What happens when a cholinergic drug has a lack of selectivity?

Answer 47

Unwanted side effects

Question 48

What are the effects of massive discharge of parasympathetic nervous system?

Answer 48

Salivation - stimulation of salivary glands Lacrimation - stimulation of lacrimal glands Urination - relaxation of urethral internal Defecation Gastrointestinal upset - diarrhea Emesis - vomiting

Question 49

What are 4 triggers of SLUDGE syndrome?

Answer 49

Drug overdose Magic mushrooms Organophosphorus insecticides Nerve agents

Question 50

What causes SLUDGE?

Answer 50

Prolonged stimulation of muscarinic acetylcholine receptors, in organs and muscles innervated by parasympathetic nervous system

Question 51

What are 3 drugs that can treat SLUDGE?

Answer 51

Atropine Pralidoxime Anti-cholinergic agents

Question 52

How is noradrenaline released?

Answer 52

Ca2+ dependent exocytosis

Question 53

Why does NA only have a limited time to influence adrenoceptors?

Answer 53

It is rapidly removed from synaptic cleft by noradrenaline transporter proteins

Question 54

What happens to NA that is not taken up into vesicles?

Answer 54

Metabolized by monoamine oxidase and catechism-O-methyltransferase

Question 55

What is an example of a adrenoceptor selective agonist?

Answer 55

Salbutamol is a beta 2 adrenoceptor selective agonist used in asthma to reverse bronchoconstriction

Question 56

Why is it important for the agonist to be selective?

Answer 56

Limit possible cardiovascular side effects

Question 57

What are happen to neurotransmitters at adrenergic synapses?

Answer 57

1. Synthesized from tyrosine to DOPA to dopamine to noradrenaline 2. Stored in vesicles 3. Released 4. After interaction, re up take into prejunctional terminal 5. Either stored in vesicle or metabolized