The Neuron

Question 1

Neural Firing Process - Resting Potential

Answer 1

when a neuron is NOT firing and has a negative charge with mostly potassium ions inside and mostly sodium ions outside.

Question 2

Polarization

Answer 2

• This means that the neuron is ”polarized,” when opposites are AWAY from each other.
• at resting potential, when sodium is on the outside,
  potassium is on the inside of a neuron.
• At this state, the neuron is at homeostasis – it’s
  a normal, happy, resting state. The state at which it
  strives to obtain regularly.

Question 3

Action Potential (“nerve impulse”)

Answer 3

The electrical pulse or “message” that travels the length of the axon.

Question 4

All-or-nothing principle

Answer 4

when the nucleus decides to fire, it fires down the axon completely (all the way) or not at all.

Likewise, maintaining the same intensity (strength/power of message) the entire length of the axon.

Question 5

Depolarization

Answer 5

when ”opposites” are no longer away from each other. This happens with action potential like a domino effect… sodium (and +) ions rush in, causing potassium (and -) ions to rush out

Question 6

Refractory period

Answer 6

The period of time after firing that the neuron is focused on resetting, and therefore is unable to fire again.

Question 7

Neurotransmitters

Answer 7

Chemical substance that crosses the synapse to carry on the message to the next neuron

Question 8

Synapse

Answer 8

open space between two neurons at which neurotransmitters cross. ( The synapse is simply a gap, an open space between neurons, and therefore NOT a part of the firing process.)

Question 9

Receptor sites

Answer 9

Specific points on dendrites of neurons that receive specific types of neurotransmitters.

Question 10

Neurotransmitters - Acetylcholine

Answer 10

Muscle contractions, memory, and learning
Associated Disorders - Alzheimer’s disease

Question 11

Neurotransmitters - Dopamine

Answer 11

Movement, thought process, Rewarding sensation
Associated Disorders - Parkinson’s, Schizophrenia, Drug addiction

Question 12

Neurotransmitters - Serotonin

Answer 12

Emotional states, sleep
Associated Disorders - Depression

Question 13

Neurotransmitters - Norepinephrine

Answer 13

Physical arousal, learning, and memory
Associated Disorders - Depression, stress

Question 14

Neurotransmitters - GABA

Answer 14

Inhibition of brain activity
Associated Disorders - Anxiety disorders

Question 15

Neurotransmitters - Endorphins

Answer 15

Pain perception, positive emotions, “runners high”
Associated Disorders - Opiate addiction

Question 16

Agonists vs. Antagonists

Answer 16

• Both are OUTSIDE (external) substances that somehow interact with neurotransmitters at the receptor sites on dendrites of a neuron
• Both interact differently at the receptor sites.

Question 17

Agonists

Answer 17

• MIMIC neurotransmitter activity
• Fitting in the receptor site like a master key – it
  works just like the original key but is not exactly the same

Question 18

Antagonists

Answer 18

• BLOCK neurotransmitter activity
• Fitting in the receptor site like a fake key, preventing the neurotransmitter from getting to its receptor site and doing its job.

Question 19

Agonists vs. Antagonists Examples

Answer 19

AGONISTS
- Morphine (opiate derivative) mimics endorphins
- Think of the effects of morphine (anesthesia)… how does that make sense given the role of endorphins?

ANTAGONISTS
- Botox (a form of botulism) blocks Acetylcholine
- Think of the role of acetylcholine… how does it make sense that botox would block its ability to do its job?

Question 20

Reuptake

Answer 20

Reabsorption of excess neurotransmitter molecules by a sending neuron - by a neurotransmitter transporter located along the plasma membrane of an axon terminal.