Brain Cell Communication Jan 21

Question 1

What is the resting membrane potential?

Answer 1

-70mV

Question 2

What are some of the forces that affect the action potential?

Answer 2

Diffusion, Electrostatic pressure, & Sodium/Potassium pumps

Question 3

Is Potassium (K+) higher inside the cell or outside the cell?

Answer 3

Higher inside the cell

Question 4

How do the forces move Potassium (K+) in and out the cell?

Answer 4

Diffusion forces it outside; electrostatic pressure forces it inside.

Question 5

How does the membrane stay at resting potential?

Answer 5

Diffusion, electrostatic pressure, & Sodium potassium pump

Question 6

Diffusion

Answer 6

hi to low concentration

Question 7

Electrostatic pressure

Answer 7

similarly charged ions repel each other (all positives will move away)

Question 8

What is depolarization?

Answer 8

The rapid shift from negative to positive of the membrane potential

Question 9

What is repolarization?

Answer 9

After the peak of depolarization, the cell begins returning to negative potential

Question 10

Depolariazation

Answer 10

Sodium rushing in

Question 11

Is Sodium (Na+) higher inside the cell or outside the cell?

Answer 11

Higher outside the cell.

Question 12

How do the forces move Sodium (Na+) in and out of the cell?

Answer 12

Diffusion forces it inside; Electrostatic pressure forces it inside.

Question 13

Sodium/Potassium pump

Answer 13

Returns membrane back to rest (-70mV); is always on

Question 14

What is depolarization?

Answer 14

The rise of membrane potential

Question 15

What is hyperpolarization?

Answer 15

Helps balance the negative back to resting potential

Question 16

What causes depolarization?

Answer 16

When a threshold of -55mV is met, voltage Na+ channels open; Na+ rush in

Question 17

When do the K+ channels open and close?

Answer 17

Always after the Na+ channels open or close; K+ exits the cell

Question 18

What happens when depolarization ends?

Answer 18

Na+ channels close; repolarization begins

Question 19

What happens when repolarization ends?

Answer 19

K+ channels close; hyperpolarization begins

Question 20

What is Absolute refractory period?

Answer 20

The time where a second action potential can not be initiated.

Question 21

What is Relative Refractory period?

Answer 21

Where a second action potential may rarely be initiated.

Question 22

When does the Absolute refractory period ends?

Answer 22

When the Na+ channels have gone back to normal within repolarization stage

Question 23

What is the All or none law?

Answer 23

The strength of the action potential is independent of the intensity of the stimulus.

Question 24

How do you code the intensity of the action potential?

Answer 24

By how many nuerons you fire/ rate of firing

Question 25

How are action potentials unitary?

Answer 25

Neurons can generate many action potentials, but it can not generate bigger of smaller action potentials.

Question 26

What is Saltatory Conduction?

Answer 26

Na+ enters at a previous node and sets up a currents that flows passively along the myelinated segment until the next node.

Question 27

What is the rate law?

Answer 27

Coding of intensity of a neuron and by the number of neurons firing.

Question 28

How are action potentials unitary?

Answer 28

Neurons can generate many action potentials, but it can not generate bigger of smaller action potentials.

Question 29

How can neurotransmitter be terminated? (3 ways)

Answer 29

Diffusion (passive), enzymatic degradation, reuptake

Question 30

What is required for the release of neurotransmitters?

Answer 30

Fusion of synaptic vesicles (requires Ca+)

Question 31

How do the transmitters molecules get to the other neuron?

Answer 31

They diffuse across synaptic cleft; bind to protein receptors in post synapse

Question 32

Transcranial Magnetic Stimulation?

Answer 32

It can be used to temporarily knock out/ enhance function in certain regions of the brain (thus can demonstrate causality).

Question 33

EEG

Answer 33

Has Low spatial resolution but high temporal resolution

Question 34

A patient thinks they either have a tumor, bone trauma, infraction, or hemmorhage. Which neuroimaging would be most likely use?

Answer 34

CT scan

Question 35

CT scan

Answer 35

Produces an image of the brain by shooting a beamo f x-rays from all angles to produce an image

Question 36

What is the first line of defense if you think someone is having a stroke

Answer 36

CT scan

Question 37

PET Scan

Answer 37

Iodine is injected into the bloodstream to image the blood vessels

Question 38

How can a DTI be useful?

Answer 38

It can be used to reconstruct white matter pathways.

Question 39

DTI

Answer 39

Looks the movement of water molecules

Question 40

EEG?

Answer 40

Brain waves; low spatial, high temporal; sleep studies, etc

Question 41

ERPs?

Answer 41

Stimulus is presented repeated and the recorded responses are averaged.

Question 42

Transcranial Magnetic Stimulation?

Answer 42

It can be used to temporarily knock out/ enhance function in certain regions of the brain (thus can demonstrate causality).

Question 43

DTI?

Answer 43

measures water diffusion along “highways”; reconstruct white matter pathways (tractography).

Question 44

Hydrophilic heads are on the___ while Hydrophobic tails on the _____

Answer 44

Outside; inside