Synapses

Question 1

How does the action potential travel?

Answer 1

from the dendrite to the axon

Question 2

What is a pre synaptic cell?

Answer 2

cell that will be transmitting or sending something to other neuron

Question 3

What is a post synaptic cell?

Answer 3

cell that receives something from another neuron

Question 4

Where does synapse occur?

Answer 4

occurs between an axon of the pre-synaptic with the dendrites of the post-synaptic

Question 5

What are the structures used to transmit the message from one neuron to the other?

Answer 5

axon terminals

Question 6

an average neuron forms and receives how many synpatic connections?

Answer 6

1000 synaptic connections

Question 7

What is synaptic transmission ?

Answer 7

is the way communication occurs between neurons in the brain

Question 8

Where does neuron communication occur?

Answer 8

at special structures called synapses

Question 9

If excitable cell membranes are in a resting state, the cells are ______?

Answer 9

polarized

Question 10

What exactly is reffered to as membrane potential?

Answer 10

differences in charges across the membrane or difference in number of cations or anions

Question 11

At a resting potential, neurons are at ?

Answer 11

-60 to -70mV

Question 12

Depolarization

Answer 12

-Making cell more positve/less negative
-Na+ enters the cell

Question 13

Hyperpolarization

Answer 13

Cell is more negative

Question 14

How does the concentration gradient moves?

Answer 14

highly to low concentrated

Question 15

Do to the concentration, how does K+,Na+,Cl- move?

Answer 15

K= is intracellular and moves toward the outside
Na= is extracellular and moves towards the inside
Cl= is extracellular and moves towards the inside

Question 16

How does the ATPase work?

Answer 16

Against concentration gradient(uses energy)
K= travels towards inside of the cell
Na=travels towards the outside of the cell

Question 17

Membrane permeability is the key to be able to create…..?

Answer 17

action potential

Question 18

During resting state, how are the Na+ and K+ gated channels?

Answer 18

closed, they are deactivated

Question 19

Voltage -gated channels only open when?

Answer 19

they are triggered by an action potential or there is a voltage difference across the cell membrane

Question 20

What are the 2 types of Na+ gated channels ?

Answer 20

gate m= known as the ACTIVATION GATE. is normally CLOSED and opens when the cell starts to get more positive

gate n= known as the INACTIVATION GATE. normally OPEN, shuts down when the cell start to get TOO positive

Question 21

What is the type of K+ gated channels?

Answer 21

gate n=is normally CLOSED, but slowly opens when the cell is depolarized (cell is very positive because Na+ enters the cell)

Question 22

What is an action potential?

Answer 22

temporary shift of the membrane potential generated by excitable cells(neurons) due to the opening of the voltage gated ion channels

Question 23

What is the function of the axon?

Answer 23

propagates the signal to the terminal and transmit to another neuron

Question 24

What is the function of the soma?

Answer 24

encode information (head of the neuron)

Question 25

What part of the neuron is the post-ganglionic neuron?

Answer 25

dendrites

Question 26

Channels open when a _____________ binds to channel and opens it ?

Answer 26

neurotransmitter

Question 27

What triggers an action potential?

Answer 27

binding of neurotransmitter(which causes the channel to open and thus depolorization occurs)

Question 28

What are the steps of an action potential?

Answer 28

#1 triggering event occurs= neurotransmitter binds to channel and causes it to open (causes positive ions to flow into inside of cell) #2 Depolarization=makes the cell less polar(makes the cells more positive/less negative) *Na+ voltage-gated channel used= m-gated channels #3 Repolarization=brings cell back to resting potential *gate h(inactivation gates) close *gate n(K+ channels) open #4 Hyperpolarization=makes cell more negative than its normal resting state #5 Resting state

Question 29

What is the type of Na+ channel present during the depolarization?

Answer 29

m-gated channel (located in the part of the axon closest to cell body) (channel activates due to the depolarization or Na+ ions entering the cell)

Question 30

At what voltage is the membrane potential able to reach a threshold?

Answer 30

when it reaches -55mV (which is when an action potential is triggered to fire)

Question 31

When is an action potential triggered to be fired?

Answer 31

when cell reaches threshold(-55mV)

Question 32

When Na+ gated channels open during depolarization, Na+ ions enter the negatively charged _______ and depolorize the surrounding __________

Answer 32

Axon-----axon

Question 33

What happens during the repolarization step?

Answer 33

-K+ channels open -K+ ions flow more towards the outside of the cell, thus making cell less positive(returning cell into resting state)

Question 34

What happens during the hyperpolarization step?

Answer 34

-cell becomes even more negative than the normal resting membrane potential -K+ channels stay open, thus letting more postive ions leave cell(making cell more negative) -when K+ channels close, sodium-potasium pump works to reestablish the resting state

Question 35

Why are the refractory periods important?

Answer 35

-so brain doesn't run out of action potentials -so brain doesn't get exhausted

Question 36

stronger the stimulus , the __________ action potential

Answer 36

stronger the signal/ frecuency of the action potential

Question 37

Stronger the action potential, _________ neuron fires up

Answer 37

faster the neuron fires up

Question 38

Refractory periods help with replenishing ______________?

Answer 38

neutransmitter so that the message can keep passing along

Question 39

When an action potential is triggered ,what happens?

Answer 39

eventually reaches axon terminal so that synapsis occurs

Question 40

What can't occur during the refractory period?

Answer 40

fire up another action potential -h-gated Na+ channels = lock so no Na+ can enter the cell (no depolarization can occur)(no action potential can be produced)

Question 41

What happens after refractory period?

Answer 41

-Na+ channels open causing depolarization and an action potential can be triggered -cell are still hyperpolarized after sending action potential so it takes more postive ions to enter cell and cause depolarization

Question 42

Refractory period can help determine the __________ of the stimulus

Answer 42

intensity of the stimulus (ej: retina cells send a bigger/faster singal in a bright light than a dimmer light)

Question 43

What are Saltatory conductions?