Cholinergic pharmacology

Question 1

what parts of the body does the autonomic system regulate?

Answer 1

smooth muscle of vessels, airway and visceral organs 
exocrine secretion (sweat)
control of heart rate 
energy metabolism in the liver 
immune system

Question 2

describe the parasympathetic ganglia

Answer 2

near their target organs, so the postganglionic fibres are short and the preganglionic fibres are long

Question 3

describe the sympathetic ganglia

Answer 3

the sympathetic ganglia are near the spinal cord (sympathetic chain) and the post ganglionic fibres are longer than the preganglionic fibres

Question 4

Which cranial nerves carry parasympathetic fibres?

Answer 4

3,7,9,10 - oculomotor, facial, glossopharyngeal, vagus

Question 5

From where do the parasympathetic nerves come from?

Answer 5

cranial ganglia

sacrum

Question 6

Name some organs that have both parasympathetic and sympathetic innervation

Answer 6

heart
gut
bladder

Question 7

Which parts of the body have sympathetic innervation only?

Answer 7

sweat glands

blood vessels

Question 8

which parts of the body have only parasymp innervation?

Answer 8

eye

bronchial smooth muscle

Question 9

which type of receptor does atropine oppose the actions of?

Answer 9

muscarinic receptors

Question 10

which type of receptor does curare oppose the actions of?

Answer 10

nicotinic receptors

Question 11

list the actions of the parasympathetic system

Answer 11

constriction of pupil
stimulation of tear glands and salivary flow
slows HR
constriction of bronchi
stimulates digestive juice secretion
stimulates intestinal motility
contracts bladder 
erection

Question 12

list the actions of the sympathetic division

Answer 12

dilates pupil
inhibition of XS saliva secretion
acceleration of heart
constriction of arterioles 
dilation of bronchi
inhibits GI motility and secretion
relaxes bladder
ejaculation

Question 13

What type of receptors are postsynaptic parasympathetic receptors?

Answer 13

muscarinic

Question 14

Where are nicotinic receptors found?

Answer 14

parasymp and symp fires coming from the CNS release Ach onto nicotinic receptors (autonomic ganglia)
NMJ
adrenal medulla
receptor in the brain

Question 15

what are the receptors of the post-ganglionic symp system called?

Answer 15

alpha and beta adrenoceptors

Question 16

what is the exception for the receptors of the post-ganglionic symp system?

Answer 16

when symp nerves innervate sweat glands, they release Ach to stimulate muscarinic receptors rather than alpha or beta adrenoceptors

Question 17

What neurotransmitters are used by the parasympathetic system that are non-cholinergic?

Answer 17

NO

VIP - vasoactive intestinal peptide

Question 18

What neurotransmitters are used by the symp system that are non-cholinergic and non-adrenergic?

Answer 18

ATP

neuropeptide Y

Question 19

What type of receptors are muscarinic receptors?

Answer 19

GPCRs

Question 20

Where are M1 receptors found?

Answer 20

brain

Question 21

Where are M2 receptors found?

Answer 21

heart

Question 22

What does atropine do?

Answer 22

M2 receptor antagonist - so can increase the heart rate for life threatening bradycardias and cardiac arrest, as parasymp usually slows the HR down

Question 23

where are M3 receptors found and what effects do they bring about?

Answer 23

glandular and smooth muscle
causes gastric, salivary secretion, GIT
smooth muscle contraction, ocular
accommodation, vasodilation, bronchodilation

Question 24

Give an example of a drug that is a muscarinic agonist and what it is used for and what is one potential side effect?

Answer 24

pilocarpine - stimulates salivation by activating the parasymp system
also constricts the pupil so can be used to treat glaucoma
side effect: slows the heart

Question 25

give examples of muscarinic antagonists

Answer 25

hyoscine
atropine
ipratropium bromide

Question 26

what is hyoscine used for?

Answer 26

motion sickness and in palliative care to reduce secretions

Question 27

give an example of a short acting M3 antagonist

Answer 27

ipratropium bromide

Question 28

give an example of a long acting M3 antagonist

Answer 28

tiotropium, glycopyrrhonium

Question 29

name an antimuscarinic drug used for treatment of an overactive bladder

Answer 29

Oxybutynin

solifenacin

Question 30

What does mebeverine do?

Answer 30

an anticholinergic drug that prevents Ach from binding to its receptor used to reduce bowel contractions in IBS

Question 31

List some actions of common drugs used in the cholinergic system either agonist or antagonist

Answer 31

• prevention of bradycardia and increase HR in cardiac arrest
• drying secretions in palliative care
• stimulation of salivation
• contraction of iris for glaucoma treatment
• treatment of broncoconstriction
• treatment of overactive bladder
• opening up of pupil to allow examination
• treatment of IBS
• travel sickness
• acetylcholinesterase inhibitors useful for treatment of dementia
• botox and cosmetics
• muscle relaxation in surgery: pancuronium and suxamethonium
• to treat myasthenia gravis

Question 32

Name some general anti-cholinergic drug side effects

Answer 32

worsening of memory
constipation
dry mouth
blurred vision (loss of accommodation reflex) 
worsening of glaucoma