Lecture 20/21- Action Potential Propagation

Question 1

True or false: There is higher concentrations of Na+ inside the cell and K+ outside the cell

Answer 1

FALSE

More K+ inside and Na+ outside

Question 2

What type of ions balance the K+ entering the cell?

Answer 2

Large Anions

Question 3

Adding more of what will open Na+ voltage gated channels

Answer 3

More positive charge

Question 4

What is depolarization?

Answer 4

The membrane potential becomes less negative, facilitating the generation of an action potential

Question 5

Na+ ions will continue entering the cell until what plugs the channel?

Answer 5

Ball and Chain

Question 6

_____ flowing into the cell has a depolarizing effect

Answer 6

Na+

Question 7

______ flowing out of the cell has a repolarizing effect

Answer 7

K+

Question 8

True or false: there is only a small number of ions involved in membrane potential

Answer 8

TRUE

Question 9

When voltage gated channels are evenly distributed along a membrane, the axons are _______

Answer 9

Unmyelinated

Question 10

What happens when voltage gated channels are not distributed evenly and are located in one place?

Answer 10

Action potential cannot be regenerated

Question 11

Distributed Na+ and K+ v-gated channels allows for what to happen?

Answer 11

Action potentials to be regenerated

Question 12

What is the refractory period?

Answer 12

Encourages one directional flow of action potentials because an increase in K+ permeability keeps Na+ channels from reopening

Question 13

What region of the neuron lacks voltage gated channels?

Answer 13

Input region

Question 14

What type of channels does the input region contain?

Answer 14

Ligan gated

Question 15

The concentric rings formed by oligodendrocytes are called

Answer 15

Myelin

Question 16

What type of cells can clear neurotransmitter from the synaptic cleft in the central nervous system?

Answer 16

Astrocytes

Question 17

What two ions are responsible for establishing an equilibrium between the electrical and chemical gradients?

Answer 17

K+ and Anions

Question 18

True or false: Action potentials can only be propagated in one direction?

Answer 18

TRUE

uni-directional

Question 19

What type of cells lay down myelin?

Answer 19

Oligodendrocytes in the CNS
Schwann cells in the PNS

Question 20

What does myelin do?

Answer 20

Increases action potentials/propagation

Question 21

At what area do voltage gated channels cluster in the plasma membrane?

Answer 21

Node of Ravien

Question 22

True or false: Action potentials are propagated node to node

Answer 22

TRUE

Question 23

What part of the neuron contains voltage gated channels?

Answer 23

Conductive region