Chapter 7

Question 1

What are the three types of ion channels

Answer 1

Leak channels, ligand-gated, voltage-gated

Question 2

When is a leak channel open

Answer 2

Always

Question 3

What causes a ligand-gated channel to open

Answer 3

When a specific chemical binds to it

Question 4

What causes a voltage-gated channel to open

Answer 4

When a specific voltage is reached

Question 5

The central nervous system is composed of what

Answer 5

Brain and spinal cord

Question 6

What are the 2 parts of the autonomic nervous system

Answer 6

Sympathetic and parasympathetic

Question 7

What are the 5 main parts of a neuron

Answer 7

Cell body, dendrites, axon, axon hillock and axon terminal

Question 8

What direction goes an action potential travel down the axon

Answer 8

From the axon hillock to the axon terminal

Question 9

What are the 3 functional classifications of neurons

Answer 9

Afferent, efferent, interneuron

Question 10

What is the difference between a graded potential and an action potential

Answer 10

Graded potential is a small change in membrane potential that degrades. An action potential will be sent down the entire axon

Question 11

What are the 3 stages of an action potential

Answer 11

Depolarization, repolarization, hyperpolarization

Question 12

What gates are the first to open when threshold is reached

Answer 12

Sodium activation gates

Question 13

What causes hyperpolarization

Answer 13

Slow closing of potassium gates

Question 14

What is resting membrane potential in a neuron

Answer 14

-70 mV

Question 15

What is the threshold potential in a neuron

Answer 15

-55 mV

Question 16

What is the all-or-none principle

Answer 16

Once threshold is reached, an action potential will occur

Question 17

What is the difference between relative and absolute refractory periods?

Answer 17

Relative - A stronger than normal stimulus will cause an action potential
Absolute - No matter what, another action potential can not occur

Question 18

The absolute refractory period occurs during what stages of an action potential

Answer 18

Depolarization and repolarization

Question 19

When does the relative refractory period occur

Answer 19

Hyperpolarization

Question 20

What 2 characteristics of a neuron will speed up transmission?

Answer 20

Increased size and myelination

Question 21

What are the 4 primary contributors to membrane potential and what do they do to membrane potential

Answer 21

Na+/K+ ATPase pump - More negative
K+ leak channels - More negative
Proteins in the cell - More negative
Na+ leak channels - Less negative

Question 22

What are the two types of graded potentials

Answer 22

Depolarizing, hyperpolarizing

Question 23

What is happening to membrane potential during depolarization

Answer 23

Less negative