nicotinic cholinergic synapse

Question 1

what is the role of vesamicol?

Answer 1

blocks transfer of ACh into vesicles

Question 2

what is the role of batulinum toxin?

Answer 2

blocks the release of Ach from nerve ending

Question 3

what is the role of anticholinesterases?

Answer 3

prevent the hydrolysis of ACh by enzyme acetylcholinesterases

Question 4

what is the role of hemicholinium?

Answer 4

blocks uptake of choline by neuromuscular junction

Question 5

n bmkx,,what is noradrenaline?

Answer 5

neurotransmitter that plays a key role in the bodys sympathetic nervous system

Question 6

where is noradrenaline synthesised and what is the rate limiting step

Answer 6

occurs in noradgrenic nerves, tyrosine hydroxylase is rate limiting step

Question 7

where does noradrenaline act on?

Answer 7

adrenergic alpha and beta adrenoceptors

Question 8

give 3 actions that happens when noradrernaline acts upon adrenergic receptors

Answer 8

increased heart rate + blood pressure
vasoconstriction
bronchodilation

Question 9

what is the role of disulfram? (synthesis)

Answer 9

inhibits dopamine beta-hydroxylate, casuing depletion of NA stores

Question 10

what is the role of reserpine? (storage)

Answer 10

blocks mechanism that transports NA into vesicles

Question 11

what is the role of tyramine (amphetamine)? (release)

Answer 11

increase release of NA from vesicles

Question 12

what is the role of nimodipine? (release)

Answer 12

reduces release by blockage of Ca2+ channels in nerve terminals

Question 13

give 4 effects of alpha 1-adrenoceptors

Answer 13

• contraction of smooth muscle (blood vessel)
• relaxation of gut smooth muscle
• salivary secretion
• hepatic glycogenolysis

Question 14

give 4 effects of alpha 2-adrenoceptors

Answer 14

• inhibition of transmitter release
• platelet aggregation
• contraction of vascular smooth muscle
• decreased insulin release

Question 15

what is the effect of beta 1-adrenoceptor

Answer 15

increased heart rate

Question 16

what is the 4 effects of beta 2-adrenocpetor?

Answer 16

• bronchodilation
• vasodilation
• muscle tremor
• relaxation of gut smooth muscle

Question 17

what is the effect of beta 3-adrenocpetor

Answer 17

lipolysios

Question 18

which adrenoceptors is adrenaline an agonists of? (epinephrine)

Answer 18

a1, a2, b1, b2

Question 19

which adrenoceptors is noradrenaline an agonists of? (norepinephrine)

Answer 19

a1, a2, b1

Question 20

which adrenoceptors is isoprenaline an agonists of? (isoproterenol)

Answer 20

b1, b2

Question 21

give an agonist of alpha 1

Answer 21

phenylephrine

Question 22

give an agonist of alpha 2

Answer 22

clonidine

Question 22

give a b1-agonist

Answer 22

dobutamine (heart failure)

Question 23

give a b2-agonists

Answer 23

salbutamol

Question 23

give a non selective a-antagonist

Answer 23

phentolamine

Question 23

give an a2-antagonist

Answer 23

yohimbine

Question 24

give an a1-antagonist

Answer 24

prazosin

Question 25

give a b1-antagonists

Answer 25

atenolol

Question 26

give a non-selectibe b-antagonist

Answer 26

propranolol

Question 27

give a b2-antagonist

Answer 27

butaxamine

Question 28

what is the PNS split into

Answer 28

somatic (effernt) system and autonomic system

Question 29

what is the role of the somatic nervous system and is it voluntary or involuntary?

Answer 29

innervates skeletal muscle - voluntary

Question 30

what is the role of the autonomic nervous system and it is voluntary or unvolntary ?

Answer 30

innervates smooth muscle (blood vessel) - involuntary

Question 31

what is the autonomic system split into

Answer 31

- sympathetic (fight or flight) - parasympathetic (rest and digestion)

Question 32

where in the PNS is ACh found?

Answer 32

somatic and parasympathetic nerves

Question 33

where in the PNS is NA found

Answer 33

postganglionic sympathetic nerves

Question 34

in the somatic nervous system where does ACh act?

Answer 34

on nicotinic receptors to cause contraction

Question 35

in the parasympathetic system where does ACh act?

Answer 35

- long preganglionic nerves release ACh to activate nicotinic receptors - postganglionic nerves release Ach to activate muscarnic receptors

Question 36

in the sympathetic system where does NA act?

Answer 36

postganglionic nerves release NA and act on adrenergic receptors

Question 36

in the sympathetic system where does ACh act?

Answer 36

- preganglionic nerves release Ach to activate nicotinic receptors

Question 37

what 3 agonists stimulate nicotinic receptors and what do they do

Answer 37

- nicotine - acetylcholine - carbachol contract muscles

Question 38

give 2 nicotinic receptor antagonists and what do they do?

Answer 38

- tubocurarine - panctonium prevent muscle action

Question 39

give 3 parasympathetic target organs that contain muscarinic receptors

Answer 39

- heart - lungs - glands

Question 40

give a muscarinic receptor agonist and what does it do?

Answer 40

- bethanechol increase secretion and decrease heart rate

Question 41

give a muscarinic receptor antagonist and what does it do?

Answer 41

- atropine increasing heart rate or relaxing airways

Question 42

give the 7 types of drug binding

Answer 42

1. covalent 2. ion-ion 3. ion-dipole 4. dipole-dipole 5. hydrogen bonding 6. van der waals 7. hydrophobic bonding

Question 43

give the 2 pharmacological options for enhancing cholinergic effects at the NMJ to treat myasthenia gravis

Answer 43

- increasing ACh in NMJ to stregnthen muscle contraction - mimic the effect of ACh at the NMJ

Question 44

what is the role of anticholinesterases

Answer 44

increase ACh at nicotinic and muscarinic receptors

Question 45

what is the role of nicotinic agonists

Answer 45

mimic the effet of ACh

Question 46

true or false skeltal muscles favour the quaternary ammonium group of Ach

Answer 46

TRUE

Question 47

true or false muscarinic receptors are more sensitive to changes in ester group

Answer 47

TRUE

Question 48

What does more potent mean

Answer 48

achieves biological response at a lower concentratiom

Question 49

what does less potent mean

Answer 49

requires a higher concentration to achieve the same effect

Question 50

what does equipotemt molar ratios show

Answer 50

hoe effective different variants of ACh are at NIC and MUS receptors

Question 51

what does higher EMR show

Answer 51

less potency

Question 52

what is the role of the ethylene bridge in ACh

Answer 52

- connects ammoinium group to ester group - maintains structural integrity -conformational flexibility - provides optimal distance between group and binding site

Question 53

what happens if you shorten the ethylene bridge

Answer 53

reduces receptor affinity

Question 54

what happens if you rigidify the ethylene bridge

Answer 54

can improve receptor selectivity by locking acetylcholine conformations

Question 55

what are rigid analogues

Answer 55

molecules designed to mimic ACh's key functional features while constrainig its conformational flexibility

Question 56

what is a pharmacophores

Answer 56

molecular structure that is required for a compound to inteact with a specific receptor

Question 57

why do NIC and MUS pharmacophores differ

Answer 57

they belong to different families

Question 58

what types of receptor is NIC

Answer 58

ligand gated ionotropic reeptor at extracellular domain

Question 59

what types of receptor is MUS

Answer 59

G-protein coupled metabotropic receptor with transmembrane region

Question 60

give the characrteristic of a nicotinic antagonist

Answer 60

biquaternary ammomium compounds (competitive antagonist)

Question 61

give 2 applications of neuromuscular blocking agents

Answer 61

- relax skeletal muscles during surgery - reduce patient movement and facilitate intubation

Question 62

give an application of ganglionic blockage

Answer 62

used for managing hypertension by reducing autonomic activity

Question 63

give the number chain length with maximum potency and the name of the ganglionic blocker

Answer 63

- 6 carbons - hexamethonium

Question 64

how does the ganglionic blocker work

Answer 64

blocks signal transmission between preganglionic and postganglionic neurons

Question 65

give the number chain length with maximum potency and the name of the neuromuscular blockers

Answer 65

- 10 carbons - decamethonium

Question 66

why do neuromuscular blockers have a longer chain length

Answer 66

- 2 ammonium groups - NMJ required longer space between ammonium groups

Question 67

what is the function of acetylcholinesterases

Answer 67

regulate ACh by hydrolysing it

Question 68

what is the function of anticholinesterases

Answer 68

enhance acetylcholine activity by inhibiting acetylcholinesterase

Question 69

give the 3 groups of anticholinesterases and their reversibility

Answer 69

1. reversible (short acting): edrophonium 2. time dependent irreversible: neostigmine 3. irreversible (organophosphorus): dyflos

Question 70

how many subunits do NIC receptors have

Answer 70

5

Question 71

briefly explain the 2 sites in acetylcholinesterases

Answer 71

1. anionic site: cation pi-interactions 2. esteric site: mediates catalysis via covalent bonding and breakdown