chapter 3 (part1)

Question 1

what is a neuron?

Answer 1

cells that communicate with the brain and body to form thought and actions

Question 2

what are the parts of a neuron?

Answer 2

1. Dendrites
2. Axon
3. Myelin
4. Nodes of Ranvier
5. Nucleus
6. Cell body

Question 3

What are dendrites?

Answer 3

They are extensions of the cell body that receive neurotransmitters from other neurons

Question 4

What is an axon?

Answer 4

Part of a neuron that delivers messages to other neurons and parts of the body

Question 5

what is an axon hillock?

Answer 5

Intersection b/w the soma and axon, where the axon begins.

Question 6

What is an axon terminal

Answer 6

part of the axon that releases the neurotransmitters

Question 7

what is the soma?

Answer 7

Cell body that controls the metabolic processing of the cell and contains all the organelles

Question 8

what is the terminal button?

Answer 8

End of the axon terminal where the neurotransmitters are released and stored

Question 9

What is a synapse?

Answer 9

Space b/w neurons

Question 10

What is a Presynaptic neuron?

Answer 10

part of a neuron that releases neurotransmitters into the synapse

Question 11

What is a synapse cleft?

Answer 11

space b/w the ends of the neuron (axon terminal) and the end of a receiving neuron (dendrite).

Question 12

What are nodes of Ranvier

Answer 12

Gaps in b/w the myelin sheaths that allow ions to change the charge inside

Question 13

What are myelin sheaths?

Answer 13

Sheaths on the axon that provide insulation for faster transportation of neurotransmitters

Question 14

What is the route of electricity?

Answer 14

Soma —> Axon hillock —> Axon —> Axon terminal

Question 15

What is the purpose of the sodium potassium pump?

Answer 15

The maintain a polarized neuron

Question 16

What is polarization?

Answer 16

When negative ions in the cell cause the neuron to have a negative charge.

Question 17

When polarization occurs, the cell will release neurotransmitters.
a) True
b) Flase

Answer 17

b) False

Question 18

What is depolarization?

Answer 18

+ charged cells moving inside the cell to make it positively charged.

Question 19

When the cell is depolarized, it will release neurotransmitters.
a) True
b) False

Answer 19

a) True

Question 20

What is the action potential?

Answer 20

It is when the inside of a neuron is positively charged and is able to send neurotransmitters. (depolarization)

Question 21

What is membrane potential?

Answer 21

It is when the inside of a cell is negatively charged and will not send neurotransmitters. (polarization)

Question 22

What is hyperpolarization?

Answer 22

Occurs during the refractory period which opens the K+ channels and causes the inside of the cell to be more negatively charged which inc the difficulty for the cell to depolarize again.

Question 23

When does the resting state occur?

Answer 23

After the refractory period where the cell sits at -70mV

Question 24

How is a cell activated?

Answer 24

By going over the threshold frequency by the opening of Na+ gated channels allowing Na+ to enter the cell.

Question 25

Where does polarization and depolarization occur in a neuron?
a) Soma
b) Axon hillock
c) dendrite
d) nodes of Ranvier

Answer 25

d) nodes of Ranvier

Question 26

How do ions get in and out of the cell?

Answer 26

The change in electrical activity opens the channels for ions to leave or enter the cell

Question 27

How is the action potential achieved?
a) Cl ions moving out of the cell
b) Na ions moving in the cell
c) K ions moving in the cell
d) a and b
e) a and c

Answer 27

d) a and b

Question 28

What causes Na+ channels to open?

Answer 28

A positive shift in electrical charge after a few Na+ ions enter the cell

Question 29

what is “saltatory conduction”?

Answer 29

The spreading of action potentials along myelinated axons from one node of Ranvier to another

Question 30

Why are hyperpolarized axons less excitable

Answer 30

They require a larger action potential.

Question 31

What depolarizes an axon?

Answer 31

K+ ions entering the neuron and Na+ leaving

Question 32

What are the different types of neurotransmitters and what do they do?

Answer 32

Excitatory: inc the probability of a neuron to be electrically active
Inhibitory: dec the probability of a neuron to be electrically active

Question 33

What are agonists?

Answer 33

Chemicals that come from out of the body that mimics neuron’s that are naturally made from inside the body (endogenous).

Question 34

What are Antagonists?

Answer 34

Chemicals that come from out of the body that inhibit a neuron from inside the body

Question 35

what are partial antagonists/agonists?

Answer 35

Chemicals from outside of the body that can partially block, mimic, or enhance an action from a neurotransmitter

Question 36

Why are Glial cells important?

Answer 36

They provide structural support, bring nutrients, remove waste/dead neurons and speed up electrical impulses

Question 37

What are efferent axons?

Answer 37

Carry elec impulses away from the CNS to trigger a neuron or hormone

Question 38

What are afferent neurons?

Answer 38

Carry impulses back to the CNS

Question 39

What is part of the CNS

Answer 39

Brain and spinal cord

Question 40

What is part of the PNS

Answer 40

Nerves outside of the cell

Question 41

What are the two parts of the PNS?

Answer 41

Somatic: voluntary
Autonomic: automatic

Question 42

What does the somatic NS do?

Answer 42

Controls movement

Question 43

What are the two parts of the Autonomic NS?

Answer 43

Sympathetic: inc heart rate and breathing
Parasympathetic: command organs to recover, digest, and become sexually aroused