Neuronal Signaling 4.2.3

Question 1

What are action potentials ?

Question 2

What is the axon?

Answer 2

Longer extension that transmits signals to neurons or other target cells

Question 3

What are dendrites?

Answer 3

Branched extension that receive signals from other neurons

Question 4

What is depolarization?

Answer 4

A decrease in the magnitude of the membrane potential

Question 5

What are gated ion channels?

Answer 5

A special type of protein channel that opens or closes in response to specific stimuli that can be chemical or electrical

-the reason why changes in membrane occur

Question 6

What are graded potentials?

Answer 6

Changes in polarization where the magnitude of the change varies with the strength of the stimulus
-small changes to membrane potential

Question 7

What is hyperpolarization?

Answer 7

An increase in the magnitude of the membrane potential

Question 8

What is a ligand-gated ion channel?

Answer 8

A channel that opens or closes in response to the chemical binding of specific ligands

Question 9

What is a myelin sheath?

Answer 9

layer of electrical insulation that surrounds vertebrate axons.

Question 10

What are nodes of Ranvier?

Question 11

What is the refractory period?

Question 12

What is the saltatory conduction?

Question 13

What is the soma?

Answer 13

Cell body or main body section of a neuron

Question 14

What is the synaptic terminal?

Answer 14

Transmit information to another cell at a junction called a synapses

Question 15

What is the voltage-gated ion channel?

Answer 15

Opens or closes in response to the changes in membrane potential

Question 16

What is a synapse?

Answer 16

Short gap between two neighboring neuron where information can be passed

-chemical signals

Question 17

What type of signals do neurons have?

Answer 17

Long-distance electrical signals and short-distance chemical signals

Question 18

What is the rising phase in active potential?

Answer 18

Increased depolarization causes more sodium channels to open, leading to an even greater flow of current

-results in positive feedback

Question 19

What is the falling phase in active potential?

Answer 19

When the membrane potential rises to a specific value, voltage-gated sodium channels become inactivated and close. However, voltage-gated potassium channels open, and potassium ions begin flowing out of the cell.

-lowers membrane potential, creating a negative feedback loop (restore to resting state