Biopsychology- Neurons

Question 1

what are the types of neurons ?

Answer 1

motor neurons, sensory neurons and relay neurons

Question 2

structure of a neuron

Answer 2

the cell body (soma) includes a nucleus, which contains the genetic material of the cell. branch-like structures called dendrites protrude from cell body. the axon carries impulses away from the cell body down the length of the neuron. axon is covered by a fatty layer called the myelin sheath that protects the axon and speeds up electrical transmission of the impulse. little gaps between myelin sheath called nodes of ranvier. at end of axon are terminal buttons that communicate with the next neuron across the synapse (gap)

Question 3

what is action potential?

Answer 3

the change in the electrical charge of a neuron that causes it to fire or not.

Question 4

briefly explain electric transmission- action potential

Answer 4

Neuron resting state = negatively charge compared to outside. When neuron is stimulated, inside of cell becomes positively charged as more positive particles enter. This initiates the action potential and results in the neuron being depolarised.
Causes an electrical impulse to travel down the axon towards the end of the neuron. Neuron then begins to move back to its polarised state as positively charged particles are pushed back out of the neuron.Means it returns to its negative resting state. This is called repolarisation.

Question 5

describe sensory neurons function:

Answer 5

these carry message from the PNS to the CNS. - unipolar: info travels down only, receptor cell always at one end. found in receptors such as eyes… translates into sensations such as vision…

Question 6

describe relay neurons function:

Answer 6

within the CNS, these connect the sensory neurons to the motor or other relay neurons. found in brain and spinal cord + visual system

Question 7

describe motor neurons function:

Answer 7

in the CNS but axons lie outside to reach muscles. these connect the CNS to effectors such as muscles and glands. release neurotransmitters that bind to receptors on muscles to trigger a response. controls muscles movements and gland activity

Question 8

describe sensory neuron structure:

Answer 8

have long dendrites and short axons, cell body in middle of axon: axon has a myelin sheath (to speed up transmission of message)

Question 9

describe relay neuron structure:

Answer 9

have a short axon, axon has NO myelin sheath (no reason to travel long distances quickly). axon projects out of cell body

Question 10

describe motor neuron structure:

Answer 10

short dendrites and long axons, axon has a myelin sheath (to speed up transmission of message)