part 2 Flashcards
A chemical messenger released by an
endocrine gland into the bloodstream and transported therein to reach its target cell.
Hormone
What are five classes of chemical messengers
- Cholinergic messengers
- Amino acid messengers
- Adrenergic messengers
- Peptidergic messengers
- Steroid messengers
What are the two cholinergic receptors in our body
- motor end plates of skeletal muscles
- sympathetic ganglia.
What is the main cholinergic messenger
Acetylcholine
Where is Acetylcholine stored?
Vesicles
What are the receptors on muscle neurons called
nicotinic receptors
When Ca2+ concentration becomes more that about ____ mM, the vesicles that contain ACh fuse with the ___________
of nerve cells and empty ACh into the _________.
-0.1
-presynaptic membrane
- synapse
The presence of ACh on the postsynaptic receptor triggers a _________ in the receptor
protein.
conformational change
K+ ions have higher concentration _______ the neuron and leave it.
inside
Na+ ions have higher concentration _____ the neuron and pass into it.
outside
summarise the storage, release and action of acetylcholine
Storage: stored in vesicles.
Release: when Ca2+ is above 0.1 micro molar . ACh fuses with presynaptic membrane and travels the synapse
Action: presence of ACh in the postsynaptic mebrane changes the receptors. PISO; Potassium inside, Sodium outside. when
The receptor protein has how many subunits??
five
How many Acetylcholine molecules needed to occupy the subunits for the ion channels to open for sodium and potassium ?
two acetylcholine molecules
what process is done to remove Acetylcholine
Hydrolysis
What enzyme catalyses the removal of ACh?
Acetylcholinesterase
