Nervous System

Question 1

Polarized

Answer 1

Means the electrical charge on the outside of the neural membrane is positive while the inside is negative

Question 2

Polarized neuron contains:

Answer 2

Excess Na on outside and excess K on inside

Question 4

Common resting potential for neuron?

Answer 4

-60mV

Question 5

Leak channels?

Answer 5

Neuron resting potential, open all the time

Question 6

Resting potential and threshold potential?

Answer 6

-60mV and -50mV

Question 7

Importance of threshold?

Answer 7

It determines if the voltage-gated ion channels will open

Question 8

Where is the trigger zone?

Answer 8

Very beginning of the axon

Question 9

Equilibrium potential of sodium?

Answer 9

50 mV

Question 10

Falling phase of the membrane/action potential?

Answer 10

Falls back down to -60mV, then goes even more negative because potassium exits the neuron and the negative protein starts to take over.

Question 11

Difference between sodium and potassium gated channels?

Answer 11

Potassium also opens when membrane potential crosses threshold, but they are slower to open.

Question 12

Rising/falling of action potential?

Answer 12

Rising: Sodium gates snap open and sodium rushes in, causing the inside to become more positive.
Falling: Slower after, potassium gates open allowing potassium to leave.
Now it’s more negative inside the neuron so there’s less force pushing potassium out

Question 13

Connection between rising/falling and polarization?

Answer 13

Rising is depolarization and falling is polarization (then hyper-polarization is at the end of the action potential)

Question 14

Hyperpolarization other name?

Answer 14

Refractory period

Question 16

Where does a sympathetic nerve originate from? Long axon or short?

Answer 16

Sympathetic nerve originates in middle of spinal cord and goes short axon to long axon

Question 18

Exitatory

Answer 18

Causes an AP (depolarization of the membrane)

Question 19

Inhibitory

Answer 19

Stops an AP (hyper polarizes the membrane)

Question 20

Reflex arc

Answer 20

When there is an automatic response to large stimulus, such as when you touch a hot burner with your hand.
This allows for immediate response without waiting for brain.
CNS is bypassed to send an immediate response to the effector cells 

Question 21

Sensory neurons

Answer 21

Environmental info from sensory receptors (PNS) to spinal cord (CNS)

Question 22

Interneurons

Answer 22

Always in spinal cord. Relays messages from sensory to motor neurons

Question 23

Motor neurons

Answer 23

Convey impulse from CNS to an effector cell

Question 24

Na/K pump active when?

Answer 24

Na pumped out/K pumped in to return to original resting state

Question 25

Depolarization is a ____swing

Answer 25

Up

Question 26

Repolarization is a ____swing

Answer 26

Down

Question 27

When an impulse reaches presynaptic membrane

Answer 27

1. Action potential reaches presynaptic membrane 2. Ca enters axon terminals 3. Ca activates proteins that pull vesicles carrying neurotransmitters to the presynaptic membrane 4. Vesicles fuse to membrane 5. Neurotransmitter is released into synaptic cleft 6. They diffuse across and bind to receptors, starting a new signal