Pharmocology of the ANS

Question 1

What receptors does sympathetic uses

Answer 1

Uses adrenoreceptors as its post synaptic receptor system.
There are 2 types, alpha and beta.
Alpha is divided to- alpha 1, alpha 2 Alpha 1 is then further subdivided into A,B and D and alpha 2 is divided into A,B,C

Beta is divided into beta 1 and beta 2.

Question 2

What receptors does the parasympathetic use?

Answer 2

Cholinoceptors, which is divided into nicotinic and muscarinic receptors.

Question 3

What are the types of channels

Answer 3

Ion channels and G-protein coupled receptors (GPCR)

Question 4

How do ion channels in parasympathetic work

Answer 4

Nicotinic receptor
Ion channels:
acetylcholine binds, which causes a conformational change in the ion channel allowing an influx of ion, which changes the potential of the membrane.

Question 5

What’s the main difference between ion channel and GPCR?

Answer 5

Ion channels, are very much on or off, you get rapid open and closure.
GPCR- their effects can last for long time.

Question 6

What’s the effect of Atropine, and how does it work

Answer 6

target the muscarinic receptor, it is a competitive muscarinic receptor antagonist.

• it will decrease heart rate
• decrease sweat production

Question 7

what can target nicotinic receptors, but why are they rarely used/

Answer 7

Tubocurarine.
Nicotinic receptor antagonist.
It is rarely used because these are also present at NMJ.
-Tubocurarine will increase heart rate( nictonic are found in the parasympathetic and sympathetic so this drug will remove the parasympathetic and sympathetic control)
-Decrease respiration (causes respiratory arrest)

Question 8

What are nictonic receptors

Answer 8

Nicotinic receptors are ionotropic receptors and are found in all autonomic ganglia.

• Binding of acetylcholine on the nicotinic receptors causes influx of other ions
• FAST TRANSMISSION.

Question 9

What are muscarinic receptors?

Answer 9

Are GPCRs.
stimulated by all postganglionic PNS neurones.
Also stimulated by SNS at selected sites.
-SLOW transmission

Question 10

What type of receptors do sympathetic nerves have and how does it work?

Answer 10

Adrenergic receptors:
Divided into alpha 1, 2 and beta 1, 2
Alpha 1:
located on the effector organ. 
Alpha 2:
Pre-synaptic receptors which prevent the release of more noradrenaline into the synapse.

Beta 1:
only FOUND in the heart, activate this and increases the CO

Beta 2:
involved =s relaxing muscles such as sphincter muscles of the GI tract

Question 11

What drugs can be used to target the sympathetic receptors?

Answer 11

Alpha 1: use doxazosin, alpha 1 receptor antagonist ( smooth muscle dilation)

Alpha 2:
Medetomidine, alpha 2 receptor antagonist ( Decreases noradrenaline)

Beta 1: Atenolol, beta 1 receptor antagonist( heart antagonist)
-would decrease heart rate (block sympathetic)

Beta 2: Salbutamol ( relaxes smooth muscle)

Question 12

what drug would you use to treat asthma attack?

Answer 12

Salbutamol

Question 13

What are some disorders of the ANS

Answer 13

Shy- Drager Syndrome/ Multiple system atrophy

• Rare
• synucleopathy- disorder of a protein which accumulates in the brain
• associated with loss of intermediolateral cell bodies.