Neurons and synaptic transmission

Question 1

Define the term neurons

Answer 1

The basic building blocks of the nervous system, neurons are nerve cells that process and transmit messages through electrical and chemical signals.

Question 2

List the types of neurons.

Answer 2

Sensory
Relay
Motor

Question 3

Define the term sensory neurons.

Answer 3

Carries messages from the peripheral nervous system to the central nervous system. They have long dendrites and short axons.

Question 4

Define the term relay neurons.

Answer 4

This connects the sensory neurons to the motor or other relay neurons. They have short dendrites and short axons.

Question 5

Define the term motor neurons.

Answer 5

This connects the central nervous system to effectors such as muscles and glands. They have short dendrites and long axons.

Question 6

Describe action potential.

Answer 6

When a neuron is in a resting state the inside is negatively charged compared to the outside. When a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second causing an action potential to occur.

Question 7

Define the term synapse.

Answer 7

The point where one neuron (presynaptic) can send a chemical reaction to an adjacent neuron (postsynaptic).

Question 8

Define the term synaptic transmission.

Answer 8

The process by which neighbouring neurons communicate with each other by sending chemical messages across the gap (synaptic cleft) that separates them.

Question 9

Define the term neurotransmitter.

Answer 9

Are brain chemicals released from synaptic vesicles that relay signals across the synapse from one neuron to another.
It’s broadly divided into excitatory and inhibitory functions.

Question 10

Define the term excitatory.

Answer 10

A neurotransmitter that increases the positive charge of the postsynaptic neuron. This increases the likelihood that the neuron will fire and pass on the electrical impulses.

Question 11

Define the term inhibitory.

Answer 11

A neurotransmitter that makes the charge of the postsynaptic neuron more negative. This decreases the likelihood that the neuron will fire and pass on the electrical impulses.

Question 12

Define the term summation.

Answer 12

Is the process that determines whether/how frequently the neuron will fire by the combined effects of excitatory and inhibitory signals.
If the neurotransmitter is excitatory then the postsynaptic neuron is more likely to fire an impulse.
If inhibitory the postsynaptic neuron is less likely to fire an impulse.

Question 13

Give an example of an excitatory neurotransmitter.

Answer 13

Adrenaline

Question 14

Give an example of an inhibitory neurotransmitter.

Answer 14

Serotonin