Nervous System

Question 1

Dendrites

Answer 1

highly branched extensions that receive signals from other neurons

Question 2

Axon

Answer 2

longer extension that transmits signals to other cells at synapses

Question 3

Axon Hillock

Answer 3

cone-shaped base of an axon

Question 4

Synapse

Answer 4

a junction between an axon and another cell

Question 5

Neurotransmitters

Answer 5

chemical messengers

Question 6

Soma

Answer 6

Cell Body

Question 7

Synaptic Terminal

Answer 7

passes information across the synapse

Question 8

Sensory Neurons

Answer 8

Transmit information about each external stimuli such as light, touch, or smell

Question 9

Interneurons

Answer 9

integrate (analyze and interpret) the information

Question 10

Motor Neurons

Answer 10

transmit signals to muscle cells, causing them to contract

Question 11

Glial Cells

Answer 11

Cells that insulate neurons

Question 12

Where is the concentration of potassium and sodium higher?

Answer 12

Higher sodium outside the cell and more potassium inside the cell.

Question 13

What energy is used in SP pump?

Answer 13

chemical potential energy

Question 14

Resting membrane potential

Answer 14

• This is always negative *usually between -50 and -70)

Question 15

How does a NAK pump work?

Answer 15

the pump moves three sodium ions out of the cell for every two potassium ions it brings in.

Question 16

Hyperpolarization

Answer 16

an increase in magnitude of the membrane potential

Question 17

Hypopolarization/Depolarization

Answer 17

easier to do work ; reduction in the magnitude of the membrane potential
(closer to 0)

Question 18

Action Potential

Answer 18

look the same in all cells ; these are used for impulses ;

Question 19

Thereshold potential

Answer 19

when it is reached, the sodium channels open and action potential is started.

Question 20

How does action potential fall?

Answer 20

Potassium leaves so charge goes back down

Question 21

Refractory Period

Answer 21

The action potential leaves the Na+ channels inactivated and K+ channels activated for a brief time to recharge.

Question 22

Do axons go in one direction or several?

Answer 22

It’s one direction

Question 23

Myelin Sheath

Answer 23

speeds up nerves

Question 24

What do we used voltage gated ion channels for?

Answer 24

To pass signal?

Question 25

What do we use ligand gated ion channels for?

Answer 25

Synapse to neurotransmitter

Question 26

Nodes of Ranvier

Answer 26

gaps in the myelin sheath coating on the neural axon ; this is where voltage gated sodium channels are

Question 27

Salatory Conduction

Answer 27

Action potentials in myelinated axons jump between the nodes of Ranvier

Question 28

What releases the neurotransmitters?

Answer 28

Calcium channels release through exocytosis

Question 29

Excitatory Postsynaptic Potentials

Answer 29

depolarizations that bring the membrane potential toward thereshold

Question 30

Inhibitory Postsynaptic Potentials

Answer 30

hyperpolarizations that move the membrane potential farther from thereshold

Question 31

Temporal Summation

Answer 31

occurs close together in time (eventually hits thereshold)

Question 32

Spatial Summation

Answer 32

axon activates multiple receptors at once