synaptic nerves and synapses

Question 1

describe the process of how an electrical impulse travels?

Answer 1

stimulus –> receptor –> sensory (electrical impulse) –> spinal cord –> brain –> spinal cord –> motor neurone –> effector

Question 2

how are impulses sped up?

Answer 2

the impulse jumps from node to node as it can not pass through the myelin sheath

Question 3

How does an impulse travel?

Answer 3

1) impulse
2) reaches the synaptic terminal where Ca 2+ ions go in –> vesicles move to membrane
3) exocytosis releases a neurotransmitter
4) neurotransmitters diffuse across the synaptic cleft
5) they then attach to a receptor on the post - synaptic membrane
6) this causes an impulse in the new nerve

Question 4

what do neurotransmitters get released by?

Answer 4

the pre-synaptic nerve releases a neurotransmitter across the synaptic cleft

Question 5

what is excitation?

Answer 5

causes depolarisation in the post - synaptic neurone so an action potential is then fired off

Question 6

what is inhibition?

Answer 6

causes hyperpolarisation in the post - synaptic neurone so no action potentials are created