Pharmacology Flashcards
What is the Name of this Nicotinic Acetylcholine receptor?
PNS
Skeletal muscle (α1)2βγε
What is the Name of this Nicotinic Acetylcholine receptor?
PNS
Ganglionic α3β4
What is the Name of this Nicotinic Acetylcholine receptor?
CNS
α4β2
What is the Name of this Nicotinic Acetylcholine receptor?
CNS
α7
Describe the key processes in cholinergic transmission aka what is going on in this diagram
- Uptake of choline via transporter
- Synthesis of ACh via choline acetyltransferase (CAT)
- Storage of ACh via transporter (concentrates)
- Depolarization by action potential
- Ca2+ influx through voltage- activated Ca2+ channels
- Ca2+- induced release of ACh (exocytosis)
- Activation of ACh receptors (nicotinic or muscarinic) causing cellular response
- Degradation of ACh to choline and acetate by acetylcholinesterase (AChE) – terminates transmission
- Reuptake and reuse of choline
What are the key features of ganglionic transmission
INWARD MOVEMENT OF POSITIVE CHARGE CAUSE DEPOLARISATION OF POST GANGLIONIC CELL BODY
Graded depolarization results in epsp
Causes all or none action potential
Describe synaptic transmission at parasympathetic neuroeffector junctions (smooth muscle, gland cell)
- Transmission at the membrane is meadiated by mascarinic receptors
- Activation of muscarinic ACh receptor subtypes (M1 – M3) causing cellular response (tissue dependent)
- Degradation of ACh to choline and acetate by acetylcholinesterase (AChE) – terminates transmission
- Reuptake and reuse of choline
Name the drug which often affect Cholinergic transmission at the ganglia?
HEXAMETHONIUM
Open channel block
What action does this cause ( parasympathetic)
GQ = Stimulation of Phospholipae C
> Increased acid secretion
What action does this cause ( parasympathetic)
Gi+ Inhibition od adenylyl cyclase- opening of K+ channels
- Decreasd heart Rate
What action does this cause ( parasympathetic)
Stimulation of phospholipase c
contraction of VISCERAL smooth muscle
What action does this cause ( sympathetic)?
Stimulation of adenylyl cyclase
> increased heart rate and force
What action does this cause ( sympathetic)?
Stimulation of adenylyl cyclase
> relaxation of bronchial and vascular smooth muscle
What action does this cause ( sympathetic)?
Stimulation of phospolipase C
> contraction of vascular smooth muscle
What action does this cause ( sympathetic)?
Inhibition of adenylyl cyclase
> inhibition of NA release
What is the affect of cocaine of the the autonomic nevous system
- Blocks reuptake of at the synaptic cleft so the concetration of NORADRENALINE rises resulting in increased adrenoceptor stimulation
>results in a raise in blood pressure which thankts to B! receptors casues heart attack
What is the affect of Amphetamine of the the autonomic nevous system
Is a substrate for UPTAKE 1 and enters the noradrenergic terminal where it inhibits MAO
enters the synaptic vesicle and displaces NA noradrenaline into the cytoplasm
Noradrenaline exits the terminal on U1 ‘running backwards’
and accumulates in the synaptic
cleft causing increased adrenoceptor stimulation
> RAISED BP > HEART ATTACK
What is the affect of PRAZOSIN of the the autonomic nevous system
antagonist of α1.
CAN BE USED TO BLOCK THE EFFECT OF NON ADRENALINE
AND RELAXES VASCULAR SMOOTH MUSCLE
used to treat hyper tension
What is the affect of Atenolol of the the autonomic nevous system
ANTAGONIST OF B1
blocks b1 on the heart decreased heart rate and force
USED TO COMBAT ANGINA AND HYPERTENSION
What is the affect of Atenolol of the the autonomic nevous system
AGONIST OF B2
Relaxes smooth muscle in airways
used as a bronchodialtor in asthma
What is the affect of Atropine of the the autonomic nevous system
PARASYMPATHETIC
Antagonist of muscarinic receptors
- USED TO REVERSE BRADYCARDIA WICH OCCURS AFTER A MYOCARDIAL INFARCTION
low doses slow heart rate so need to be very careful whne prescribing
