Neural Transmission

Question 1

define neuroscience

Answer 1

the science of the nervous system

Question 2

What is the role of a neuron?

Answer 2

to pass on messages

Question 3

Why is it important for a neuron to carry out its message?

Answer 3

messages enable thinking, behaviour and many other different workings of the brain

Question 4

What is the nervous system made up of?

Answer 4

nerve cells and glial cells

Question 5

What are the functions of glial cells?

Answer 5

carrying out repairs, insulation, waste disposal, transmitting messages, protecting neurons and providing neurons with nutrients

Question 6

How do glial cells carry out their functions?

Answer 6

they release neurotransmitters (which also have a role in message transmission) in the hippocampus

Question 7

What role do glial neurotransmitters have?

Answer 7

role in synaptic transmission and clearing neurotransmitters away from the synaptic gap

Question 8

How do glial cells help form a myelin sheath?

Answer 8

they wrap around nerve fibres to form a myelin sheath

Question 9

What is the role of the myelin sheath?

Answer 9

are there for protection around their axon: can help repair (e.g. if there is damage to the spinal cord) and conduct messages

Question 10

What is the difference between motor and sensory neurons?

Answer 10

Motor neurons receive messages from the CNS to generate movement whereas sensory neurons transmit sensory messages from the sensory organ to the CNS

Question 11

What is the role of inter-neurons?

Answer 11

they take messages from one neuron to another

Question 12

What is the axon?

Answer 12

It can be up to 1m long in humans and is the long strip between the body of the neuron and the terminals - it is protected by the myelin sheath

Question 13

What is the myelin sheath made up of?

Answer 13

Schwann cells in the PNS and oligodendroglial cells in the CNS
(these provide insulation)

Question 14

What is the function of the gaps in the myelin sheath?

Answer 14

called the Nodes of Ranvier, and help messages travel faster

Question 15

What is the purpose of the axon hillock?

Answer 15

Situated at the end of the soma, it controls the firing range of the signals along the axon

Question 16

What are the terminals?

Answer 16

Situated at the end of the axon, these transmit messages through the synaptic gap to other neurons

Question 17

How are electrical signals created within a neuron?

Answer 17

By ions: When voltages of ions differ significantly both inside and outside of the neuron, it creates an action potential within the cell body which travels along the axon via the axon hillock, sped up by the Nodes of Ranvier and protected by the myelin sheath to the terminals which release a neurotransmitter

Question 18

Why does the myelin sheath make messages travel more quickly?

Answer 18

Conductivity of the sheath

Question 19

define dendrites

Answer 19

the tree-like structures that receive signals from other neurons.

Question 20

Why is Ramon-y-Cajal (1894) used to understand neural transmission?

Answer 20

Ramon-y-Cajal (1894) was the first scientist to describe the structure of neurons in detail. It had previously been believed that the brain consisted of a continuous network of tissue. Ramon-y-Cajal discovered that each neuron was a separate cell, not joined directly to any others. He concluded that each neuron must be capable of both (1) transmitting signals within itself; and (2) sending signals to other neurons. This discovery underpins all of modern biopsychology and neuroscience.

Question 21

define neuron

Answer 21

the main cell of the nervous system

Question 22

define action potential

Answer 22

the electrical signals that are sent from the dendrites to the terminals of a neuron.

Question 23

define dendrites

Answer 23

the tree-like structures that receive signals from other neurons.

Question 24

define axon

Answer 24

the long, branching structure that transmits the action potential to the terminal, allowing neural signals to be sent over (potentially) long distances.

Question 25

define terminal

Answer 25

the structure where action potentials finish, and chemical signals are sent to other neurons.

Question 26

define myelin sheath

Answer 26

a fatty substance wrapped around the axons of some neurons. It allows action potentials to travel faster.

Question 27

define ions

Answer 27

charged particles. The movement of ions allows the action potential to happen.

Question 28

define firing rate

Answer 28

the frequency with which a neuron produces action potentials. A neuron’s firing rate increases or decreases in response to the signals it receives from other neurons at its dendrites.

Question 29

What research methods are used to understand neural transmission?

Answer 29

The use of animals in psychological research: most of what we know about neurons and neural transmission we learned by experimenting on the neurons of giant squid.