SYnapses

Question 1

Westerhat are synpases?

Answer 1

= gaps between the end of one neuron and the dendrite of the other
= the action potential is is transmitted as neurotransmitters, acetylcholine
this diffuses across the snyapse

Question 1

How do synapses work?

Answer 1

1: an action potential arrives at synaptiic knob, depolorisation of the synpatic knob means that Ca2+ ions channels and Ca2+ ion diffuse into synpatic knob
2: vesicles containing neurotransmitters, move towatds and fuse with the presynaptic membrane, neutrotransmitter is released, exocytosis to the synpatic cleft

3: neutrotranitters diffuse down the synpase, down the concentration gradient, to the pist synpatic membrane, neurotrnamistter binds to the complementary receptor, on the cell syrfave ,e,brame of the postsynatpitc membrane

4: Na+ ion channels on the post synpatic membrane open and Na+ diffuses in, if enough neurotransmitters, than enough Na+ ions diffuse in above threshold and becomes depoloriased

5: Neurotransmitter is degraded, and released from the receptor, Na+ channels close, and post synaptic membrane, can resablish resting potential,
= neurotransmitter transported back, into presynatmic membrane where it is recylced

Question 2

What happens with a cholingenic synpase?

Answer 2

= acetyl choline
= enzyme: acetylchoineesterase
= braks acetytl chloline into choline and acetate and is recyled back into presynmatpuc knob and goes into making more acetyl choline

Question 3

What is a nueromuscular junction?

Answer 3

= occurs between the motor nueron and muscle fivre, not a gap between 2 nuerons
= only exciterory,
= connects motor nueron to muscle
= this is end point for action potential- takes to effector
= acetyl choline binds to the rectepors on muscle fibres

Question 4

How can drugs affect synapses?

Answer 4

= mimics shape of nuerotransmitter so is able to bind to the complementary recpetors on the post synpatic emmbrane- leads to formation of action potential
= may block or inhbiit the receptor site binding site, preventing acetyl choline from binding, so there is no generation of an action potential
= binds to the enzyme, so no enzyme substrate complexs, so new regeneration cotnious impulse
= cause release or block of nueotransmitters