Cholinergic and Adrenergic Pharmacology

Question 1

what are Cholinergic medications?

Answer 1

act upon the neurotransmitter acetylcholine, ACh and its receptors

Question 2

what are Adrenergic medications?

Answer 2

bind to adrenergic receptors throughout the body. (these are (nor)adrenaline receptors)

Question 3

describe structure of :
central ,
Peripheral,
somatic
autonomic,
sympathetic
parasympathetic nervous systems

Answer 3

nervous system has the CNS and PNS

PNS = all nerves outside brain and spinal cord

PNS has somatic and autonomic

autonomic has sympathetic (fight and flight) and parasympathetic (rest and digest)

Question 4

main 2 differences between somatic and autonomic systems

Answer 4

somatic
- 1 neurone from CNS to muscle
- voluntary control of skeletal muscle

autonomic
- 2 neurones (pre an post ganglionic)
- involuntary control

Question 5

what are the 2 areas of Parasympathetic nerve nuclei

DETAIL

Answer 5

brain: Cranial nerves 3,7,9,10 (remember 1973)

sacral outflow innervating the pelvis: at vertebrae T12-L1 and exit at S2-S4

Question 6

what are the relative lengths of the pre and post ganglionic nerve fibres in the parasympathetic system?

Answer 6

Long preganglionic fibre (from spinal cord or brain to near organ target)

Short post ganglionic fibre (reach target and release acetylcholine, ACh)

Question 7

where are the sympathetic ganglia?

Answer 7

in a chain beside the vertebrae

Sympathetic trunk along side vertebral canal from T1 to L2

Question 8

what are the relative lengths of the pre and post ganglionic nerve fibres in the sympathetic system?

Answer 8

Short preganglionic fibres

synapse within trunk

Long post ganglionic fibres (to target)

Question 8

what are the relative lengths of the pre and post ganglionic nerve fibres in the sympathetic system?

Answer 8

Short preganglionic fibres

synapse within trunk

Long post ganglionic fibres (to target)

Question 9

what are the 2 main neurotransmitters?

Answer 9

Acetylcholine (Ach)
Noradrenaline (Nad)

Question 10

Pregnalionic mediators:

which neurotransmitter acts on which receptors

is it different for para and sympathetic?

Answer 10

Ach acts on nicotinic receptors for both parasympathetic and sympathetic

Therefore both para + symp can be stimulated by nicotine SAME

Question 11

Postganglionic mediators :

which neurotransmitter acts on which receptors

is it different for para and sympathetic?

Answer 11

Ach acts on muscarinic receptors in parasympathetic

Nad acts on alpha and beta receptors in sympathetic

Question 12

what are 3 examples of exceptions to the Pregnalionic mediators and Postganglionic mediators trends?

Answer 12

Sweat glands have sympathetic postganglionic fibres that release ACh to stimulate muscarinic receptors

Nitric oxide is released from parasympathetic postganglionic termini in blood vessels

Multiple transmitters can be released at once to cause mixed effects (eg. ATP)

Question 13

what are the 2 types of cholinergic receptors?

Answer 13

receptors ACh can act up on:

nicotinic

muscarninc

Question 14

is Ach acting on nicotinic receptors a cholinergic reaction in the parasympathetic and/or sympathetic NS?

Answer 14

Nicotine stimulates both parasympathetic and sympathetic

Question 15

is Ach acting on muscarinic receptors a cholinergic reaction in the parasympathetic and/or sympathetic NS?

Answer 15

parasympathetic nervous system

with the exception of sweat glands (sympathetic stimulation, but still ACh and muscanrinc receptors )

Question 16

how many Muscarninc (M) receptors are there and how do they work?

Answer 16

5 types of M receptor,

all found on cell membrane and they active intracellular processes through G proteins

G proteins can activate various types of second messenger signals with different consequences for the cells

Question 17

where are M1 receptors found?

Answer 17

brain

Question 18

where are M2 receptors found?

if activated, in short, what happens

Answer 18

1. SA node of heart (pacemaker)
2. AV node of heart

activation decreases Heart Rate

Question 19

where are M3 receptors found?

Answer 19

1. reps tract
2. GI tract
3. skin
4. urinary tract
5. eyes

Question 20

M3 receptors:

what does activation of M3 receptors in the respiratory tract cause?

Answer 20

reps tract –>

• bronchoconstriction (smooth muscle contraction in airways)
• produces mucus in airways and nasopharynx

Question 21

M3 receptors:

what does activation of M3 receptors in the GI tract cause?

Answer 21

GI tract –>

increases saliva production, gut motility and biliary secretion

Question 22

M3 receptors:

what does activation of M3 receptors in the skin cause?

Answer 22

skin –>

sweating

(sweat glands are sympathetic, therefore this is an exception)

Question 23

M3 receptors:

what does activation of M3 receptors in the urinary tract cause?

Answer 23

urinary tract–>

contracts detrusor muscle + relaxes internal sphincter therefore you urinate

Question 24

M3 receptors: what does activation of M3 receptors in the eye cause?

Answer 24

eye --> myosis (reduces pupil), increases drainage of aq humour causes secretion of tears

Question 25

what is Muscarine poisoning ?

Answer 25

when the M receptors are activated inappropriately eg. blurred vision, diarrhoea, bradycardia

Question 26

which cholinergic drugs are used to treat glaucoma?

Answer 26

Pilocarpine eye drops they are M3 agonists Increases drainage of aqueous humour → reduces ocular pressure

Question 27

which cholinergic drugs are used to treat AV node block?

Answer 27

Atropine - dilates the pupils, increases HR it is an antagonist, so blocks activation of M2 receptors in heart therefore prevents HR decrease

Question 28

if tiotropium is an inhaled antagonist medication used to treat bonchoconstriction a. what receptors is it acting on? b. what side effects could result from acting on these receptors ?

Answer 28

a. treats bronchonconstriction by causing bronchodilation. therefore is an anti-muscarninc drug targeting M3 receptors b. antagonist to M3 could cause - dry mouth - uriniary retention - worsening existing glaucoma

Question 29

what is ACh used for within the CNS? what impact could anticholinergics therefore have in the CNS?

Answer 29

neurotransmitter involved in memory therefore anticholinergics can causes memory problems and confusion

Question 30

give examples of ACh outside the autonomic nervous system

Answer 30

1. CNS, brain, memory 2. somatic, causes flaccid paralysis in skeletal muscle, therefore cosmetic use (BoTox) 3. ACh activates nicotinic receptors in somatic, therefore N1 blockers

Question 30

give examples of ACh outside the autonomic nervous system

Answer 30

1. CNS, brain, memory 2. somatic, causes flaccid paralysis in skeletal muscle, therefore cosmetic use (BoTox) 3. ACh activates nicotinic receptors in somatic

Question 31

what receptors and neurotransmitters are involved in anaesthesia?

Answer 31

Ach uses N1 receptors in somatic NS (activates skeletal muscle) therefore N1 blockers can cause muscle relaxation and therefore used as anaesthetics

Question 32

what is the acronym SLUDGE used for? what does it stand for?

Answer 32

to help remember the common symptoms of certain affections of a cholinergic crisis (too much cholinergic): "salivation, lacrimation, urination, defecation, gastrointestinal upset, emesis".

Question 33

briefly explain Ach movement at the synaptic cleft

Answer 33

chief neurotransmitter of the parasympathetic nervous system ACh diffuses across the synaptic cleft and binds to receptors on the postsynaptic or the postjunctional membrane. The binding of ACh to its receptors produces a conformational change in a membrane channel that is specifically permeable to both Na+ and K+. ACh is concentrated at the synaptic cleft

Question 34

within what NS, and on what receptors does noradrenaline activate?

Answer 34

Nad acts on alpha and beta adrenergic receptors in sympathetic NS postganaglionic fibres

Question 35

Nad. adrenaline and dopamine are all examples of what?

Answer 35

catecholamines

Question 36

what are the different types of adrenoreceptors? what type of reception are they?

Answer 36

2 alpha adrenoreceptors (alpha 1, alpha 2) 3 beta adrenoreceptors (beta 1,2,3) G protein coupled receptors

Question 37

what does the activation of alpha 1 receptors (by adrenaline or noradrenaline) cause?

Answer 37

vasoconstriction (especially in blood vessels and pupils and skin) causes an increase in blood pressure and cardiac work

Question 38

give a use of adrenaline and a use of noradrenaline medication

Answer 38

adrenaline will raise BP therefore used to treat anaphylaxis noradrenaline given for IV shock

Question 39

what does the activation of alpha 2 receptors (by adrenaline or noradrenaline) cause? where are alpha 2 receptors found?

Answer 39

has mixed effects on smooth muscle lowers blood pressure, reduced vascular tone found in brain and peripherally

Question 40

what could alpha 1 antagonists be used for?

Answer 40

block the increase of blood pressure therefore can be used to treat hypertension

Question 41

what does the activation of beta 1 receptors (by adrenaline or noradrenaline) cause? where are they found?

Answer 41

Heart, kidney, fat cells activation will increase heart rate and chronotropic effects causes lipolysis and hyperglycaemia (to assist flight/flight)

Question 42

what does the activation of beta 2 receptors (by adrenaline or noradrenaline) cause?

Answer 42

relaxes smooth muscle

Question 43

what can beta 2 agonists be used for?

Answer 43

treat asthma delay onset of premature labour however are side effects eg. risk of arrhythmias

Question 44

what does the activation of beta 3 receptors (by adrenaline or noradrenaline) cause?

Answer 44

relaxes bladder detrusor muscles enhances lipolysis

Question 45

what can beta 3 agonists be used for?

Answer 45

reduce over-active bladder symptoms

Question 46

what can beta blockers be used for?

Answer 46

to treat hypertensions, heart failure, angina

Question 47

what condition of patient would make you weary to prescribe beta blockers?

Answer 47

asthmatic patients beta agonists are bronchodilators therefore blockers can cause constriction

Question 48

what are side effects of beta blockers?

Answer 48

Tiredness Bronchoconstriction Bradycardia Cardiac depression