Synapses

Question 1

What happens when nerve impulse arrives at the pre synaptic membrane

Answer 1

It depolarises it causing voltage gated calcium channels to open

Question 2

What happens to calcium ions released by the voltage gated channels

Answer 2

They eneter the pre synaptic cell down the conc gradient

Question 3

What does an influx of calcium ions cause

Answer 3

It causes vesicles to bind with the presynaptic membrane and releases neurotransmitters into synaptic cleft

Question 4

What happens when neurotransmitters bind to receptors

Answer 4

Ligand gated sodium channels open and sodium ions diffuse in which depolarises the post synaptic membrane and initiates action potential in the post synaptic neurone

Question 5

What is acetyle choline hydrolysed by and into what

Answer 5

Hydrolysed by acetyle choline esterase into Ethanoic acid and choline

Question 6

What happens to acetyle choline once hydrolysed

Answer 6

Ethanoic acid and choline diffuse back into pre synaptic membrane and for lm neurotransmitters in vesicles

Question 7

What are the functions of synapses

Answer 7

To transmit impulses between neurons
Make sure impulses pass in one direction
They allow aclimitisation
They allow summation

Question 8

What is acclimatisation

Answer 8

After repeated stimulation a synapse might run out of neurotransmitters which allow it to filter out low level stimuli