Neurons and synaptic transmission

Question 1

What are neurons?

Answer 1

Nerve cells that process and transmit messages through electrical and chemical signals

Question 2

What is the role of sensory neurons?

Answer 2

Carry messages from PNS to CNS

Question 3

What is the role of relay neurons?

Answer 3

Connect sensory neurons to motor and other relay neurons

Question 4

What is the role of motor neurons?

Answer 4

Connect CNS to effectors (e.g. muscles and glands)

Question 5

What is the order of neurons?

Answer 5

Sensory > Relay > Motor

Question 6

What is the structure of sensory neurons?

Answer 6

Long dendrites
Short axons

Question 7

What is the structure of relay neurons?

Answer 7

Short dendrites
Short axons

Question 8

What is the structure of motor neurons?

Answer 8

Short dendrites
Long axons

Question 9

Where are sensory neurons located?

Answer 9

Fully PNS

Question 10

Where are relay neurons located?

Answer 10

Fully CNS

Question 11

Where are motor neurons located?

Answer 11

PNS and CNS

Question 12

Which neuron does not have a myelin sheath?

Answer 12

Relay neurons

Question 13

What is the function of the nucleus (neurons)?

Answer 13

Contains genetic material of the cell

Question 14

What is the function of dendrites (neurons)?

Answer 14

Carry nerve impulses from neighbouring neurons towards cell body

Question 15

What is the function of the axon (neurons)?

Answer 15

Carries nerve impulses away from the cell body, down the length of the neuron

Question 16

What is the function of the myelin sheath (neurons)?

Answer 16

Protects the axon and speeds up electrical transmission of the impulse

Question 17

What is the function of nodes of ranvier (neurons)?

Answer 17

Speed up transmission of the impulse, by forcing it to jump across the gaps along the axon

Question 18

What is the function of terminal buttons (neurons)?

Answer 18

Communicate with the next neuron in the chain, across a synapse

Question 19

How are signals WITHIN neurons transmitted?

Answer 19

Electrically

Question 20

How are signals BETWEEN neurons transmitted?

Answer 20

Chemically

Question 21

What are neurotransmitters?

Answer 21

Brain chemicals that relay signals across the synapse from one neuron to another

Question 22

What is excitation?

Answer 22

When a neurotransmitter increases the positive charge of the postsynaptic neuron, it increases the likelihood that the postsynaptic neuron will pass on the electrical impulse

Question 23

What is inhibition?

Answer 23

When a neurotransmitter increases the negative charge of the postsynaptic neuron, it decreases the likelihood that the postsynaptic neuron will pass on the electrical impulse

Question 24

What is summation?

Answer 24

The process that determines whether or not action potential will be generated by the combined effects of inhibitory and excitatory signals

Question 25

What is synaptic transmission?

Answer 25

The process by which neighbouring neurons communicate with each other by sending chemical messages across the synpase

Question 26

How does synaptic tranmission occur?

Answer 26

• Action potential travels down the axon of the presynaptic neuron
• Triggers release of neurotransmitter from synaptic vesicles
• AP to postsynaptic neuron, where neurotransmitters binds to receptor cells