cholegernic synapse

Question 1

what is the purpouse of synaptic transission

Answer 1

to allow action potential to be passed along to the next neurone/cell

Question 2

descrbe the process of synaptic transmission across a choligernic synapse

Answer 2

• action potential arrives at presynaptic nurone
• action potential stimulates voltage gated calcium ion channels on presynaptic neurone to open
• calcium ions diffuse down to synaptic knob
  -influx in calcium ions into synaptic knob causes synaptic vesicles to fuse with presynaptic membrane
• vesicles release neurotransmiter acetlycholine into synaptic cleft
• acetyl choline diffuses across synaptic cleft and binds with specific cholegernic receptors on post synaptic neurone
• causes sodium ion channels to open on post synaptic neurone.
• influx of sodium ions causes depolarisation and stimulates generation of action potential
• acetylcholine removed from synaptic cleft and broken down by enzyme acetylcholiesterase
• reabsorbed into presynaptic neurone

Question 3

how do synapses ensure nerve impulse is undirectional

Answer 3

receptors only present on postsynaptic membrane

Question 4

why are excess neutransmiters removed from synaptic cleft

Answer 4

so response doesn’t keep occouring

Question 5

give one way excess neurotransmitters are removd from the synaptic cleft

Answer 5

via enzymes e.g acetylcholinesterase