Chapter 3 pt.1

Question 1

What is the Human Nervous System

Answer 1

Includes the spinal cord and the brain which sends and receives messages to and from all areas of your body. The nervous system is a maze of complex cellular networks that relay and process information (create behaviour)

Question 2

Which two cells are in the nervous system

Answer 2

Neurons and Glial cells

Question 3

What is the meaning of ‘Neural’

Answer 3

relating to the nervous system

Question 4

What are Neurons

Answer 4

They are cells that communicate within the brain and with the body to form thoughts

Question 5

What are Neurons

Answer 5

They are cells that communicate within the brain and with the body to form thoughts and actions

They code information as electrical signals and release chemical signals that influence other parts of the body

Question 6

What are dendrites

Answer 6

They are extensions of the cell body that branch out to communicate with other neurone

Question 7

What are the chemical signals called and what do they bind too

Answer 7

Neurotransmitters

They bind too receptors

Question 8

What is excitation and inhibition

Answer 8

Excitation is when neurotransmitters tell the neutron to “activate” and Inhibition is when it tells it to quiet down

Question 9

What are Receptors

Answer 9

Proteins in the cell body membrane that receive chemical messages from neurotransmitters.
When a neurotransmitter binds to a receptor it can influence the behaviour of the cell.

Question 10

What is the Soma

Answer 10

The soma is the cell body of the neutron. It contains the organelle and controls the metabolic processing

Question 11

What is the Axon

Answer 11

the long narrow projection from the cell body that acts as a wire transmitting the signal from the soma to the end of the axon (axon terminals)

Question 12

What is the Axon Hillock

Answer 12

the axon hillock is the intersection between the soma (cell body) and the axon. It’s where the axon begins

Question 13

what is the Axon Terminals

Answer 13

The part of the axon that releases the neurotransmitter when the action potential gets to it

Question 14

What are the Terminal Buttons (synaptic knobs)

Answer 14

the ends of the axon terminal where the neurotransmitter exits

Question 15

What are vesicles

Answer 15

little bubbles at the terminal button that store neurotransmitter molecules

Question 16

What is the Synaptic Cleft

Answer 16

the space between two neurons, usually the axon terminal and the dendrite

Question 17

What is the Synapse

Answer 17

The synapse is the small fluid-filled gap between neurons In which neurotransmitters are released

Question 18

What are the Postsynaptic Receptors

Answer 18

It’s the other side of the synapse. The neuron that contains the receptors (usually dendrites) that are ready to bind to neurotransmitters released from the postsynaptic neuron

Question 19

Whats Myelin

Answer 19

Myelin is a protein fatty substance that wraps around the axon to protect and increase speed of action potentials (electrical impulses)

It keeps the electrical impulse flowing down the axon

Question 20

What are the Nodes of Ranvier

Answer 20

Gaps in the myelin that allow ions to enter into the axon and change the charge inside the cell, which allows for a more efficient signal transmission

Question 20

What are the Nodes of Ranvier

Answer 20

Gaps in the myelin that allow ions to enter into the axon and change the charge inside the cell, which allows for a more efficient signal transmission

Question 21

What are Ions? Name some

Answer 21

Ions are positive or negative charges, the movement of ions create electricity.

Na+ Cl- K+

Question 22

When is a cell considered “Polarized”

Answer 22

When a large number of negatively charged ions inside the cell causes the neutron to have a negative charge

usually -70 Millivolts (mV)

When the cell is polarizes it is at rest and won’t release neurotransmitters

Question 23

What is depolarization

Answer 23

When there are more positive charged particles in the cell causing the neuron to be positively charged

The more depolarized the neuron is, the more likely it is to activate (action potential) and send a neurotransmitter to another neuron/organ

Question 24

How do Ions get in and out of the cell??

Answer 24

Through the membrane, it has several doors, or channels that open in different ways.

Question 25

What do voltage gated channels do (party reference)

Answer 25

When there are only a few doors open for there Na+ ions but a lot of them, the voltage gated channels decide to allow more doors to open to allow even more Na+ so it can hit its climax action potential)

Question 26

What is propagation

Answer 26

the process where electrical impulses get sent to the end of a neuron

Question 27

How is a neutron “turned off” after the action potential (rush of Na+ inside)

Answer 27

The k+ ions leave when the Na+ comes in to allow the neutron to return to its resting potential, it “resets” the neutron

Question 28

What is the first stage of action potential

Answer 28

Threshold - the amount of voltage change required to trigger the opening of voltage gated channels in the cell (caused by Na+ entering)

Question 29

what is the second step of action potential

Answer 29

Depolarization - positively charged ions moving into the cell making it de-polarized which occurs in the nodes of ranvier

Question 30

What is the third step of action potential

Answer 30

Repolarization - when the Na+ ions cause the k+ channels to leave

Question 31

What is the fourth step of action potential

Answer 31

Refractory period - when the K+ channels remain open until the neutron becomes hyper-polarized which temporary increases the difficulty to reach threshold again

Question 32

What is the fifth step of action potential

Answer 32

Resting state - the neutron stabilizes and returns to its resting state potential, usually -70 mV