2.1 The Structure Of The Neuron And The Neural Impulse

Front 1

What happens when a neuron is at rest?

Back 1

A neuron is not firing neural impulses or messages it is actually electrically charged.

Front 2

What is inside and surrounding a neuron?

Back 2

A semi-liquid solution contains both positively and negatively charged ions.

Front 3

What is inside a neuron?

Back 3

There is mostly negatively charged ions that are so big that they can't get out.

Front 4

What is surrounding the neuron?

Back 4

Outside there are lots of positively charged sodium ions, they are unable to enter the cell membrane when the cell is at rest .

Front 5

Why do sodium ions cluster around the membrane?

Back 5

Sodium ions cluster around the membrane because the outside of the neuron is positive and the inside of the neuron is negative, so they attract to each other.

Front 6

What is the resting potential?

Back 6

The resting potential is the state of the neuron not firing a neural impulse.

Front 7

How are the sodium ions allowed to enter the cell?

Back 7

The sodium ions are allowed to enter the cell when there is a strong enough stimulation from another cell, meaning that the dendrites are activated.

Front 8

What happens when the sodium ions enter the cell?

Back 8

The inside of the cell becomes mostly positively charged and the outside of the cell becomes mostly negatively charged.

Front 9

Where does the electrical charge reversal start?

Back 9

The electrical charge reversal will start at the axon closest to the soma and then proceed down the axon.

Front 10

What is the action potential/electric change reversal?

Back 10

The action potential is the release of the neural impulse consisting of a reversal of the electrical charge within the axon.

Front 11

How long does each action potential sequence last?

Back 11

Each action potential sequence takes about 1000th of a second. Meaning that neural messages can travel from 2 mph to 270 mph.

Front 12

What happens when the action potential reaches the end of the axon?

Back 12

The message will get transmitted to another cell.

Front 13

How does the cell return to the resting state? (Step 1)

Back 13

The sodium ions "gates" immediately close after the action potential has passed.

Front 14

How does the cell return to the resting state? (Step 2)

Back 14

The cell membrane pumps positive sodium ions back outside.

Front 15

How does the cell return to the resting state? (Step 3)

Back 15

The small positively charged potassium ions inside the neuron move rapidly out of the cell after the action potential passes.

Front 16

How does the cell return to the resting state? (Step 4)

Back 16

The positively charged potassium ions help to more quickly restore the inside of the cell to a negative charge.

Front 17

What is the nervous system?

Back 17

An extensive network of specialized cells that carries information to and from all parts of the body.

Front 18

What is the central nervous system?

Back 18

The central nervous system is the brain and the spinal cord.

Front 19

What does the peripheral nervous system do?

Back 19

The peripheral nervous system transmits information to and from the central nervous system.

Front 20

What does the brain do?

Back 20

The brain interprets and stores information and sends orders to muscles, glands, and organs

Front 21

What is the spinal cord?

Back 21

The spinal cord is a pathway connecting the brain and the peripheral nervous system.

Front 22

What does the autonomous nervous system do?

Back 22

The autonomous nervous system automatically regulates blood vessels, blood pressure, internal organs, glands, digestion, and pupil dilation.

Front 23

What does the somatic nervous system do?

Back 23

Carries sensory information and controls the movement of skeletal muscles.

Front 24

What does the parasympathetic division do?

Back 24

The parasympathetic division maintains body functions under ordinary conditions and saves energy.

Front 25

What does the sympathetic division do?

Back 25

The sympathetic division prepares the body to react and it expands energy in times of stress.

Front 26

What is neuroscience?

Back 26

Neuroscience it is a branch of the life sciences that deals with the structure and function of neurons, nerves, and nervous tissue, especially focusing on their relationship to behavior and learning.

Front 27

Who is Santiago Ramon y Canal?

Back 27

He was the first to theorize that the nervous system was made of cells.

Front 28

What is the neuron?

Back 28

The neuron is the specialized cell within the nervous system that sends and receives messages within the nervous system.

Front 29

What are dendrites?

Back 29

Are branch-like structures that receive messages from other neurons. ​

Front 30

What is the soma?

Back 30

The soma is the cell body of neurons responsible for maintaining the life of the cell.

Front 31

What is an axon?

Back 31

An axon is a tube-like structure that carries the neural message to other cells.

Front 32

What is myelin?

Back 32

Myelin is fatty substances produced by certain glial cells that coat the axons of neurons to insulate, protect, and speed up the neural impulse.

Front 33

What do oligodendrocytes do?

Back 33

Oligodendrocytes produce myelin in the brain and the spinal cord.

Front 34

What do Schwann cells do?

Back 34

Schwann cells produce myelin in the neurons of the body.

Front 35

What are nerves?

Back 35

Nerves are bundles of axons coated in myelin that travel together through the body.

Front 36

What does myelin speed up and offer protection to?

Back 36

Myelin offers a little protection from damage and it speeds up the neural message traveling down the axon, because the neural message travels down an axon (coated with myelin), it jumps between myelin sheath sections.

Front 37

What does multiple sclerosis do?

Back 37

Multiple sclerosis damages Myelin sheath which leads to loss of function in those cells.

Front 38

What is the neurilemma?

Back 38

The neurilemma is the thin membrane coated on axons of neurons in the body and it surrounds the axon and myelin sheath, serves as a tunnel so damaged nerve fibers can repair themselves.

Front 39

How is the neuron charged during its resting potential?

Back 39

The neuron is negatively charged inside and positively charged outside.

Front 40

What does an action potential cause?

Back 40

An action potential causes a reversal of the electrical charge from negative to positive.

Front 41

What happens to the cell areas behind the action potential

Back 41

The cell areas return to their resting state of a negative charge as the sodium ions are pumped out and the potassium ions rapidly leave.

Front 42

When can it be said that a neuron returned to its resting potential state?

Back 42

Once the sodium ion pumps finish pumping out the sodium ions.

Front 43

What 2 types of signals for a neuron are there?

Back 43

Signals that are meant for the neuron to fire and signals mean for the neuron to not fire.

Front 44

How does a neuron fire a signal?

Back 44

A neuron fires a signal in an all-or-none fashion, meaning a neuron either fires completely or does not fire at all.

Front 45

What is the difference between a strong stimulation and a weak stimulation?

Back 45

A strong stimulation will cause the neuron to fire more quickly and will cause more neurons to fire.