Biopsychology - Neurons & Synaptic Transmission

Question 1

What is a neuron?

Answer 1

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

Question 2

What are the 3 types of neurons?

Answer 2

Relay
Motor
Sensory

Question 3

Where are relay neurons located?

Answer 3

In the central nervous system

Question 4

What is the function of the relay neuron?

Answer 4

Connect sensory neurons to the motor & other relay neurons

Question 5

What are the characteristics of relay neurons?

Answer 5

Have short dendrites & axons

Question 6

Where are motor neurons located?

Answer 6

The peripheral nervous system

Question 7

What is the function of motor neurons?

Answer 7

Connect the central nervous system to effectors (muscles/glands)

Question 8

What are the characteristics of motor neurons?

Answer 8

Short dendrites & long axons

Question 9

Where are sensory neurons located?

Answer 9

The peripheral nervous system

Question 10

What is the function of a sensory neuron?

Answer 10

Carry messages from the peripheral nervous system to the central nervous system

Question 11

What are the characteristics of sensory neurons?

Answer 11

Have long dendrites & short axons

Question 12

What are the characteristics of all neurons?

Answer 12

Dendrites
Cell body
Nucleus
Node of ranvier
Myelin sheath
Schwann cell
Axon
Terminal buttons

Question 13

Describe how an electrical signal is sent over neurons

Answer 13

A dendrite receives a signal from another neuron which is passed down the axon. The myelin sheath & Schwann cells surrounding the axon, increases the speed at which the signal is transmitted which ends up reaching the terminal buttons at the end of the neuron. The electrical impulse is then sent to the next neuron.

Question 14

What is stage 1 of synaptic transmission?

Answer 14

An action potential arrives at the axon terminal. The vesicles with the neurotransmitter merge with the membrane

Question 15

What is stage 2 of synaptic transmission?

Answer 15

The neurotransmitters are released into the synaptic cleft and diffuse across the synapse to reach the post synaptic cleft

Question 16

What is stage 3 of synaptic transmission?

Answer 16

Summation

Question 17

What is summation?

Answer 17

The combined effect of all the excitatory & inhibitory neurotransmitter influences on the post synaptic neuron

Question 18

What happens if the threshold is reached during summation?

Answer 18

if a threshold is reached then a new action potential is formed in the post synaptic cell

Question 19

What are excitatory neurotransmitters?

Answer 19

Neurotransmitters that increase the likelihood of a new action potential forming in the cell.
They make the charge of the cell more positive & more likely to fire when detected (depolarisation)
Positively charged sodium ions enter the post synaptic cell

Question 20

What are inhibitory neurotransmitters?

Answer 20

Neurotransmitters that decrease the likelihood of a new action potential forming in the cell.
They make the charge of the cell more negative & less likely to fire when detected (hyperpolarisation)
Positively charged potassium ions leave the post synaptic cell

Question 21

What is stage 4 of synaptic transmission?

Answer 21

Some neurotransmitters are reabsorbed into the presynaptic cell after transmitting neurotransmitters which happens between transport proteins -> SSRIS