3.2 The Electrochemical Actions of Neurons: Information Processin

Question 1

What are the two stages/kinds of electrical signals between Neurons?

Answer 1

Transmission

Conduction

*both of these together define what is known as “Electrochemical Action” of neurons

Question 2

The movement of electrical signals within a neuron, form the Dendrites, to the Cell Body, then throughout the Axon

Answer 2

Conduction

Question 3

Movement of electric signals from one neuron to another as a result of chemical signaling across the synapse.

Answer 3

Transmission

Question 4

What is meant by “Resting Potential”?

Answer 4

The difference in electric charge between the inside and outside of a neuron’s cell membrane.

Neurons have a natural electric charge, as discovered in the 1930s

Question 5

What causes a difference in Resting Potential?

Answer 5

difference in concentrations of ions inside and outside the neuron’s cell membrane.

Question 6

How is a neuron charged while in natural resting potential?

Answer 6

Negatively, as the inside of the cell membrane is negatively charged compared to the outside

Question 7

What’s an Action Potential?

Answer 7

An electric signal that is conducted along a neuron’s axon to a synapse.

Question 8

What’s the resting charge of the inside of a neuron relative to the outside?

Answer 8

-70 millivolts

Question 9

What chemistry happens as a result of Action Potential?

Answer 9

Starting from both channels being closed, electric stimulation of the neuron opens the Na+ (sodium) channels to allow flow in and increase the positive charge inside the axon relative to the outside.

After action potential reaches it’s maximum, the Na+ channel closes, and the K+ one opens, returning the charge of the neuron back to negative relative to the outside.

Question 10

What’s the “Refractory Period”?

Answer 10

The time following an action potential during which a new action potential cannot be initiated.

Happens when Na+ channels inactivate themselves for several milliseconds, blocking the flow of Na+ ions

Question 11

What are the breakpoints in Myelin Sheath called?

Answer 11

Nodes of Ranvier, as discovered by the French pathologist

Question 12

What are the steps of Synaptic Transmission?

Answer 12

1) The action potential travels down the axon and
(2) stimulates the release of neurotransmitters from vesicles.
(3) The neurotransmitters are released into the synapse, where they float to bind with receptor sites on a dendrite of a postsynaptic neuron, initiating a new action potential. The neurotransmitters are cleared out of the synapse by
(4) reuptake into the sending neuron,
(5) being broken down by enzymes in the synapse, or
(6) binding to autoreceptors on the sending neuron.

Question 13

What is Acetylcholine?

Answer 13

A neurotransmitter involved in a number of functions, including VOLUNTARY MOTOR CONTROL

Question 14

A neurotransmitter that regulates motor behaviour, motivation, pleasure, and emotional arousal.

Answer 14

Dopamine

Question 15

The major excitatory neurotransmitter in the brain, meaning that it enhances the transmission of information between neurons.

Answer 15

Glutamate

Question 16

Particularly involved in states of vigilance, or a heightened awareness of dangers in the environment

Answer 16

Norepinephrine

Question 17

involved in the regulation of sleep and wakefulness, eating, and aggressive behaviour

Answer 17

Serotonin

Question 18

Chemicals that act within the pain pathways and emotion centres of the brain

Answer 18

Endorphins

“runner’s high”

Question 19

The primary inhibitory neurotransmitter in the brain, meaning that it tends to stop the firing of neurons

Answer 19

GABA (Gamma-aminobutyric acid)

Question 20

What are Agonists/Antagonists?

Answer 20

Agonists are drugs that increase the action of a neurotransmitter.

Antagonists are drugs that block the function of a neurotransmitter.