What are the two types of autonomic receptors?
Cholinergic and Adrenergic
Cholinergic - stimulated by ACh
Adrenergic - stimulated by noradrenaline and adrenaline
What are the types of Cholinergic receptors?
Nicotinic and Muscarinic
What are the Nicotinic receptors?
Nn and Nm
Where are Nicotinic receptors found?
The Adrenal Medulla
What are Cholinergic receptors?
They are stimulated by ACh
What are Adrenergic Receptors?
They are stimulated by Noradrenaline and Adrenaline
When stimulated what do Nicotinic receptors do?
They increase Na influx into cells
Where are Nn receptors found?
At autonomic junctions
Where are Nm receptors found?
What are the Muscarinic receptors?
M1, M2 and M3
When stimulated what do Muscarinic receptors do?
They stimulate G proteins
What types of G proteins are there?
Gq, Gi and Gs
What does Gq do when stimulated?
Increase stimulation of Phospholipase C
What does Gi do when stimulated?
Inhibit adenyl cyclase
What does Gs so when stimulated?
Stimulation of adenyl cyclase
When stimulated, what does M1 do?
- Increased acid secretion in the stomach
- Increases gland secretion in the ENS
When stimulated, what does M2 do?
- Decreases HR by increasing SA-AV node delay
When stimulated, what does M3 do?
M3 gives a "wet picture" - lots of secretions
- Contraction of visceral smooth muscle (bronchoconstriction)
- Increased secretion of Saliva
- Increases Vasodilation
- Pupil constriction
- Relaxed sphincters
- Vomiting/urination etc
What are the types of Adrenergic receptors?
Alpha, Beta and Dopamine
What are Alpha receptors?
A1 and A2
Where are M1 receptors found?
In the ENS and the CNS
Where are M2 receptors found?
In Cardiac Muscle
Where are A1 receptors found?
In the heart and vascular smooth muscle
Where are A2 receptors found?
In some vascular smooth muscle
Where are B1 receptors found?
In the heart
Where are B2 receptors found?
In respiratory and vascular smooth muscle
What is the opposite of the B1 receptor?
The M2 receptor
When stimulated, what does A1 do?
- Increases vasoconstriction through contraction of vascular smooth muscle
- Increases HR
- Increases the force of contraction of the heart
- Pupil dilation
- Constricts sphincters
When stimulated, what does A2 do?
- Inhibits noradrenaline release
When stimulated, what does B1 do?
- Increases the force of contraction of the heart (SV)
- Increases HR by decreasing the SA-AV node delay
- Increases CO (SV X HR)