Neuronal Communicaion t

Question 1

What causes calcium channels to open at the presynaptic knob? What is the effect of this?

Answer 1

Action potential opens voltage gated calcium ions which flood into neuron from outside membrane. This causes vesicles to fuse with presynaptic membrane and neurotransmitters are released into synaptic cleft

Question 2

What happens when neurotransmitter (acetylcholine) is released from presynaptic knob?

Answer 2

Released into cleft, binds to receptor site on the sodium ions which flood channels, sodium ion channels open.

Sodium channels open changes shape and opens allowing sodium ions to diffuse into neuron from a cause depolarisation.

Question 3

What does acetylcholinesterase do?

Answer 3

Enzyme that breaks acetylcholine down into acetyl and choline. Sodium channels close, the two bits diffuse back across the cleft to the presynaptic neurone which allows the neurotransmitter to be recycled.

Smooth Endoplasmic reticulum and ATP from mitochondria help to reform acetylcholine

Question 4

What is a unidirectional synapse?

Answer 4

Delivers a message in one direction from axon terminals to dendrites of the next neurone

Question 5

What is a summation synapse?

Answer 5

Can collect multiple smaller messages leading to the formation of an action potential

Question 6

Inhibition synapse?

Answer 6

Provides a gap in sending of the message where the message could be interrupted ]

Question 7

Role of the neurotransmitter:

Answer 7

Diffuse across synapse, bind to receptor, change shape of protein allowing it to open and cause action potential

Question 8

Role of the synapse:

Answer 8

Allows neurones to converge and diverge information
Multiple signals can be sent
Ensures action potentials travel in one direction
Allows acclimatisation
Creates memory