L6-Synapses and signal transmission

Question 1

NMJ

Answer 1

Neuro-muscular junction

place of synapse between the pre-synaptic cell- motor neuron and post synaptic cell-muscle fibre.

Question 2

Name two types of Gated ion channels

Answer 2

1) voltage gated ion channels- membrane potential

2) ligand gated ion channels- signalling molecules

Question 3

Which has a faster inactivation rate- Na or Ca

Answer 3

Na

Question 4

what is crucial for synaptic transmission

Answer 4

voltage gated Ca channels which have v steep conc gradient must open
vvvvvv small ICF

Question 5

Exocytosis

Answer 5

type of Active Transport, requires ATP

Removes molecules like neurotransmitters out of cell

Question 6

NB Neurotransmitter at NMJ for skeletal muscle

Answer 6

ACh

Question 7

where is ACh a transmitter in - i.e. what type of NS is it a neurotransmitter

Answer 7

Somatic nervous system (NMJ)
ANS- Preganglionic fibres (Symp and Parasymp)
Postganglionic fibres (Parasymp)
CNS

Question 8

nAChR Features

Answer 8

nicotinic acetylcholine receptor
Ligand gated ion channels
open when ACh attatches to them
NB- permeable to Na and K ions

Question 9

Postsynaptic response - EPP

Answer 9

End Plate Potential
depolarization of skeletal muscle caused by neurotransmitter binding to the post-synaptic membrane in the NMJ
think diagram

Question 10

Summary of transmission at NMJ

Answer 10

AP- travels down soma of axon
ACh released into vesicles (initiated by AP)
Calcium voltage gated channels open & (Ca) intracellular concentration increases
Causes vesicles containing ACh to bind to membrane
ACh binds and activates nAChR- permeable to Na & K
Na depolarises membrane- muscle contraction

Question 11

how do u terminate this reaction

Answer 11

AChE Acetyl choline Esterase
Acetyl; moves into ECF &; removed by bloodstream
Choline; axon terminal -recycled 
ACh moves off receptor 
Receptor closes 
Synaptic transmission - over