Synapses

Question 1

synapses

Answer 1

• gaps between nerve cells
• action potentials cannot pass between nerve cells between the synapse so transmitter substances are used

Question 2

structure of a synapse

Answer 2

• structure is the junction between two neurones
• presynaptic membrane allows the release of chemicals (neurotrasmitters) when impulses are arriving to stimulate impulses in the cell after the gap

Question 3

Typical synapse

Answer 3

• has a presynaptic knob which contain vesicles filled with neuro transmitters
• receptor molecules on post synaptic membrane bind with neurotransmitter

Question 4

The steps within synapses

Answer 4

-an action potential arrives
-the membrane depolarises
-calcium ions cause synaptic vesicles to fuse with presynaptic membrane
- neurotransmitter is released into synaptic cleft
-neurotransmitter binds with receptors on postsynaptic membrane
-membrane depolarises and initiates an action potential
- when released the neurotransmitter is taken across the presynaptic membrane

Question 5

Acetylcholine

Answer 5

• first neurotransmitter
• helps the stimulation of muscles
  -largely made in the brain
• broken down in the synaptic cleft by acetylcholinesterase