Biopsych: Neurons And Synaptic Transmission

Question 1

How many neurons are in the nervous system?

Answer 1

100 billion

Question 2

What percentage of neurons are located in the brain?

Answer 2

80%

Question 3

What is the primary function of neurons?

Answer 3

Transmit electrical and chemical signals

Question 4

What are the three types of neurons?

Answer 4

• Sensory neurons
• Relay neurons
• Motor neurons

Question 5

What do sensory neurons do?

Answer 5

Carry messages from PNS to CNS

Question 6

What is the structure of sensory neurons?

Answer 6

Long dendrites and short axons

Question 7

What do relay neurons connect?

Answer 7

Connect sensory to motor and other relay neurons

Question 8

What is the structure of relay neurons?

Answer 8

Short dendrites and long axons

Question 9

What do motor neurons connect?

Answer 9

Connect CNS to effectors (muscles and glands)

Question 10

What is the structure of motor neurons?

Answer 10

Short dendrites and long axons

Question 11

What is the maximum length a neuron can vary?

Answer 11

Up to a metre

Question 12

What is the basic structure of all neurons?

Answer 12

Cell body, dendrites, axon, terminal buttons

Question 13

What does the cell body of a neuron contain?

Answer 13

Nucleus with genetic material

Question 14

What are dendrites and their function?

Answer 14

Branches that carry nerve impulses to the cell body

Question 15

What does the axon do?

Answer 15

Carries impulse away from the cell body

Question 16

What covers the axon?

Answer 16

Myelin sheath

Question 17

What is the function of the myelin sheath?

Answer 17

Protects axon and speeds up electrical transmission

Question 18

What are nodes of Ranvier?

Answer 18

Separate the myelin sheath

Question 19

What are terminal buttons?

Answer 19

Communicate with the next neuron

Question 20

Where are motor neuron located?

Answer 20

Cell body: In the CNS
Axon: form part of PNS

Question 21

Where are sensory neurons found?

Answer 21

In the PNS in clusters (ganglia)

Question 22

Where are most relay neurons found?

Answer 22

Within the brain and visual system

Question 23

What is the charge of a neuron in a resting state?

Answer 23

Negatively charged

Question 24

What happens when a neuron is activated by a stimulus?

Answer 24

Inside becomes positively charged for a split second, causing action potential

Question 25

What does action potential create?

Answer 25

An electrical impulse that travels down the neuron

Question 26

What is synaptic transmission?

Answer 26

An electrical signal reaches the end of one nerve cell and releases neurotransmitters

Question 27

What are neurotransmitters?

Answer 27

Chemicals that carry signals between neurons

Question 28

What happens when neurotransmitters reach the next neuron?

Answer 28

Triggers an electrical signal in the next nerve cell

Question 29

How do neurons communicate with each other?

Answer 29

In groups (neural network)

Question 30

What are synapses?

Answer 30

Tiny gaps that separate neurons

Question 31

What type of transmission occurs WITHIN neurons?

Answer 31

Electrical transmission

Question 32

What type of transmission occurs BETWEEN neurons?

Answer 32

Chemical transmission

Question 33

What triggers the release of neurotransmitters?

Answer 33

An electrical impulse reaching the presynaptic terminal ## Footnote presynaptic terminal: end of neuron

Question 34

Where are neurotransmitters released from?

Answer 34

Tiny sacs called Synaptic Vesicles

Question 35

What effect can neurotransmitters have on neighboring neurons?

Answer 35

* Excitatory effect * Inhibitory effect

Question 36

What does the neurotransmitter serotonin cause?

Answer 36

Inhibition in the receiving neuron ## Footnote Leads to a negative charge making it less likely to fire

Question 37

What does the neurotransmitter adrenaline cause?

Answer 37

Excitation in the receiving neuron ## Footnote Leads to a positive charge making it more likely to fire

Question 38

Fill in the blank: Neurotransmitters diffuse across the synapse to the next neuron and are received by _______.

Answer 38

[postsynaptic receptor site] ## Footnote On the dendrite of the next neuron

Question 39

What happens to the chemical message after a neurotransmitter crosses the gap?

Answer 39

Converted back into an electrical impulse and the process beings again with the next neuron