Nervous System- SYNAPSE

Question 1

Synapse- 2 Kinds

Answer 1

How neurons communicate. Neurons can have 20,000 synapses

1. Chemical
2. Electrical

Question 2

A. Chemical synapse

Answer 2

uses neurotransmitter (N.T.)

1. axon terminal of presynaptic neuron (synaptic knob)
2. synaptic cleft (gap)
3. dendrite or cell body of postsynaptic neuron contains receptors for N.T., channels and enzymes

Summary: an “action potential” (nerve impulse) reaching the synaptic knob causes exocytosis of the N.T. The N.T. diffuses across the synaptic cleft, binds to the receptor, which causes the channels to open or close. This sets up changes in the 2nd (postsynaptic) neuron.

Question 3

What happens at a chemical synapse?

Answer 3

Summary: an “action potential” (nerve impulse) reaching the synaptic knob causes exocytosis of the N.T. The N.T. diffuses across the synaptic cleft, binds to the receptor, which causes the channels to open or close. This sets up changes in the 2nd (postsynaptic) neuron.

Question 4

2 neurotransmitters

Answer 4

Ach (acetylcholine)

N.E. (norepinephrine)

Question 5

synapse

Answer 5

neuron to neuron

Question 6

neuromuscular junction

Answer 6

neuron to muscle cell

Question 7

B. Electrical Synapse (junction)

Answer 7

Gap Junction (intercalated disc)