Lecture 4

Question 1

Depolarization is the the result of

Answer 1

Na+ entering the cell

Question 2

New Na+ channels open when

Answer 2

Graded potential crosses threshold potential

Question 3

The inside of the cell becomes positively charged when

Answer 3

Na+ channels open and allow Na+ to enter the cell

Question 4

Depolarization comes after

Answer 4

Graded potential

Question 5

Voltage-gated Na+ channels are involved in

Answer 5

Depolarization

Question 6

Repolarization is caused by the

Answer 6

Movement of K+ ions out of the cell

Question 7

What happens during Repolarization?

Answer 7

Inside returns back to a net negative charge, near resting membrane potential

Question 8

Voltage gated K+ channels are involved in

Answer 8

Repolarization

Question 9

What happens during Hyperpolarization?

Answer 9

Cell drops briefly below the resting membrane potential

Question 10

How are the concentrations of K+ during Hyperpolarization?

Answer 10

Equal at both sounds of the membrane

Question 11

How is Hyperpolarization corrected?

Answer 11

By using active transport to move K+ back into the cell, returning the cell to -70mV

Question 12

What should tell us about the function of the neuron?

Answer 12

Its structure

Question 13

What are the three types of neurons?

Answer 13

• Sensory Neurons
• Brain Neurons
• Vertebrate Motor Neurons

Question 14

Describe Sensory Neurons:

Answer 14

• One end has dendrites that allow sensory neurons to connect to different neurons
• Another has receptor associated with particular sense

Question 15

Olfactory receptors are activated by

Answer 15

Chemicals in the air

Question 16

Brain Neurons are known as

Answer 16

Interneurons

Question 17

Describe Brain Neurons”

Answer 17

• Large number of dendrites on both ends to maximize connections with other neurons
• Short axon
• Send and receive messages over short distances between neurons

Question 18

Describe Vertebrate Motor Neurons:

Answer 18

• Long axons for long distances
• Myelinated
• One end branches into neuromuscular junctions that connect neuron with target muscle cell
• Other end has lots of dendrites to connect muscles to the brain or spinal cord

Question 19

Graded potentials form in the

Answer 19

Soma

Question 20

The formation of graded potentials results in the

Answer 20

Formation of the action potential

Question 21

Graded potentials are formed when

Answer 21

Na+ channels open

Question 22

The Axon Hillock is responsible for

Answer 22

Integration

Question 23

Graded potential travels through the soma towards the

Answer 23

Axon hillock

Question 24

What happens in the Axon hillock?

Answer 24

The graded potential crosses threshold potential and causes action potential

Question 25

Threshold potential is crossed and AP is triggered in axon hillock when

Answer 25

Enough Na+ enters the soma

Question 26

The Axon Hillock is the region where

Answer 26

Graded potentials cause APs