Neuronal Communication

Question 1

What is cell signalling?

Answer 1

One cell releases a chemical which has an affect on another cell.

Question 2

Homeostasis

Answer 2

Maintenance of a constant internal environment.

Question 3

What are axons?

Answer 3

Transmit impulses away from the cell body.

Question 4

What are dendrons?

Answer 4

Short extensions from the cell body which divide into dendrites.

Question 5

What is the cell body?

Answer 5

Contains nucleus surrounded by cytoplasm which contains many ER and mitochondria which are involved in the production of neurotransmitters.

Question 6

What are neurotransmitters?

Answer 6

Chemicals which are used to pass signals from one neurone to the next.

Question 7

What is myelin sheath?

Answer 7

Many layers of plasma membranes produced by schwann cells which wrap around the axon many times.

Question 8

What do Pacinian corpuscles detect?

Answer 8

Mechanical pressure

Question 9

Where are Pacinian corpuscles located?

Answer 9

Finger and soles of feet

Question 10

How do Pacinian Corpuscles work?

Answer 10

1) In resting state, stretch mediated channels are too narrow to allow sodium ions to pass through them. It is at resting potential.
2) When pressure is applied, the corpuscle changes shape.
3) The sodium ion channels widen so sodium ions diffuse into the neurone.
4) The influx of sodium ions depolarises the membrane. This results in a generator potential.
5) This creates an action potential.