Lecture 3

Question 1

Creating action potentials in the nervous system are necessary for

Answer 1

Muscle contraction

Question 2

What is Osmoregulation?

Answer 2

Controlling concentration of ions and water in and out of the cell

Question 3

What are Action Potentials?

Answer 3

Electrical signals that are used by cells of the nervous system to communicate

Question 4

Action Potentials are made when

Answer 4

Charged ions move from one side of the membrane to the other, down their concentration gradient

Question 5

What produces electrical signals?

Answer 5

Movement of charged ions from one side of the membrane to the other

Question 6

For Action Potentials to be made, there needs to be

Answer 6

A concentration gradient

Question 7

What is the Resting membrane potential?

Answer 7

-70 mV

Question 8

The Goldman Equation is used to

Answer 8

Calculate the resting membrane potential

Question 9

What does the Goldman Equation consider?

Answer 9

• Concentration of ions on each side of the cell membrane
• The relative permeability of the membrane to these ions
• The charges of these ions

Question 10

Action potentials used by the nervous system are created by

Answer 10

Altering the permeability of the membrane to ions

Question 11

Facilitated diffusion occurs when the

Answer 11

Gates of ion channel proteins open

Question 12

Action potentials are started by weaker electrical signals called

Answer 12

Graded Potentials

Question 13

When do Graded Potentials form?

Answer 13

When a stimulus causes gates on Sodium Ion Channels to open

Question 14

What are the different stimuli used to open Na+ channels?

Answer 14

• Binding of a specific molecule

- Change in pressure

Question 15

Ligand-Gated Sodium Channel open in response to the

Answer 15

Binding of a specific molecule

Question 16

Mechano-Gated Sodium Channel open in response to

Answer 16

A change in pressure

Question 17

Neurotransmitters (like acetylcholine) or chemicals used in sense of taste / smell use which kind of Sodium channels?

Answer 17

Ligand-Gated Sodium Channels

Question 18

Sense of touch or changes in blood pressure use which kind of Sodium channels?

Answer 18

Mechano-Gated Sodium Channel

Question 19

What happens when sodium channels open?

Answer 19

The movement of sodium into neuron causes for a graded potential

Question 20

What happens as Na+ rushes into the cell?

Answer 20

The inside of the cell becomes more positively charged

Question 21

Why is there a Plateau at +60mV?

Answer 21

At this potential, the concentration of Na+ is equal on both sides of the membrane, so there is no concentration gradient

Question 22

If enough sodium moves into the neuron during the graded potential, the membrane potential will

Answer 22

Cross the threshold potential (-50mV)

Question 23

Crossing the threshold potential results in the

Answer 23

Triggering of AP

Question 24

What are the Phases of AP?

Answer 24

Depolarization
Repolarization
Hyperpolarization

Question 25

Each phase of the action potential is caused by the

Answer 25

Opening and closing of new ion channels