Autonomic Cholinergic Physiology Flashcards
What is the major neurotransmitter in the ANS?
Acetylcholine
What are the 2 major sites in which acetylcholine acts in autonomic transmission?
Communication between all Preganglionic and postganglionic autonomic neurons, communication between all postganglionic parasympathetic neurons and their target organs
What is the postganglionic neurotransmitter that stimulates the target organ in the SNS?
Norepinephrine
What type of stimulation slows the heart?
Vagal stimulation
What is the transferable chemical mediator released by stimulation of the vagus nerve?
Acetylcholine
Is ANS effects on target organs electrical or chemical?
Chemical
What muscle in the eyes causes accommodation?
Ciliary muscle
In general what are the effector functions of the PNS?
Smooth muscle contraction, glandular secretion, cardiac inhibition
What are coupled to second messenger systems which in turn trigger the target cell response?
Muscarinic Ach receptors
What type of receptors are metabotropic, trigger intracellular biochemical cascades, are relatively slow sustained processes, recruit multiple effectors, undergo amplification of signal?
Muscarinic ACh receptors
How many ACh muscarinic receptor subtypes are there?
5
What is the second messenger in muscarinic receptors (M3,M1,M5)?
IP3 (phospholipase C system)
The binding of ACh to a muscarinic ACh receptor stimulates what type of G protein? (M3,M1,M5)
Gq
What is the end product of the phospholipase C system, that triggers the opening of the ER lumen causing a large increase in intracellular Ca+?
IP3 (M3,M1,M5)
The Gq protein stimulates what system to produce the second messenger IP3?
Phospholipase C system
What type of ACh muscarinic receptors cause smooth muscle contraction and stimulation of secretion?
M3 (also M1,M5)
The binding of ACh to a muscarinic ACh receptor stimulates what type of G protein? (M2,M4)
Gi
Gi inhibits what from converting ATP to cAMP?
Adenylate Cyclase system