Reflex arc/action potential

Question 1

What is a reflex arc

Answer 1

-Simple connection of neurons that results in involuntary reflex action to a stimulus

Question 2

How does neuron communicate with other neurons, muscles, and glands

Answer 2

they use electrical signals called nerve impulses

Question 3

What is resting membrane potential

Answer 3

The difference across a membrane in a resting neuron

Question 4

What is a mV of a resting membrane potential (polarization)

Answer 4

Its -70mV

Question 5

How does sodium postassium pump contribute to resting membrane potential

Answer 5

-Uses ATP to transport 3 Na+ out of the cell and 2 K+ into the cell
-It results in a constant membrane potential of -70mV

Question 6

True or false: Is action potential an all of none phenomenon

Answer 6

yes, if a stimulus causes the axon to depolarizae to a certain level

Question 6

What causes an depolarization to occur

Answer 6

Action potential

Question 6

What is depolarisation

Answer 6

-occurs when cell becomes less polarised (reduced to less than the resting membrane potential of -70mV)
- the inside of the cell becomes less negative relative to outside

Question 7

What is the threshold potential

Answer 7

its -50mV

Question 8

Does the strength of an action potential increase based on the strength of the stimulus

Answer 8

No only the frequency does

Question 9

At +40mV which channel is inactivated and which one opens

Answer 9

-Na+ channels are inactivated
-K+ channel open and posstasium ions exit to hyperolarize the membrane

Question 10

at the threshold potential (-50mV) which channel opens

Answer 10

Na+ channel open and Na+ RUSHES INTO cell to depolarise the membrane

Question 11

After membrane undergoes an action potential what is it called

Answer 11

refractory period

Question 12

What is the exposed area of myelinated axons called

Answer 12

nodes of ranvier

Question 13

Does action potential jump from one node of ranvier to the next?

Answer 13

Yes

Question 14

The junction between two neurons or between a neuron and a effector is called

Answer 14

Synapse

Question 15

Do neurons connect or have a small gap

Answer 15

They have a small gap called synaptic cleft

Question 16

How can nerve impulses be sent if nerve impulses can’t jump across one neuron to another

Answer 16

Chemical messengers called neurotransmitter carry the nerve impulses

Question 17

What is presynaptic neuron

Answer 17

Sends out the information

Question 18

What is post synaptic neuron

Answer 18

Reveives the information

Question 19

What is step one of synapse

Answer 19

Nerve impulse travels to synaptic terminal

Question 20

What is step 3 of synapse

Answer 20

Synaptic vesicles release neurotransmitter into synaptic cleft by exocytosis
Neurotransmitter diffuse across the synapse to reach the postsynaptic neuron or the cell membrane of an effector

Question 21

What is step 2 of synapse

Answer 21

Synaptic vesicles containing neurotransmitter move toward and fuse with presynaptic membrane

Question 22

What is step 4 of synapse

Answer 22

-Neurotransmitters bind to specific receptor proteins on the postsynaptic membrane.
-The receptor proteins trigger ion
channels to open.
-Depolarization of the postsynaptic membrane
occurs, and an action potential is initiated if the threshold potential is reached.

Question 23

What is an ecxitatory effect on post synaptic cleft

Answer 23

causes action potentials by opening sodium channels

Question 24

What is an inhibitory effect on post synaptic cleft

Answer 24

Inhibitory molecules cause potassium channels to open, causing hyperpolarization.