Neurons

Question 1

Types of neurons

Answer 1

• sensory
• motor
• interneurons

Question 2

Sensory neurons

Answer 2

Conduct information towards the central nervous system

Question 3

Motor neurons

Answer 3

carry information from central nervous system to an effector (muscle or gland)

Question 4

Interneurons

Answer 4

Interpret sensory signals and initiate a response

Question 5

Cell body of a neuron

Answer 5

Processes signal received

Question 6

Dendrites

Answer 6

Receive signals

Question 7

Axon

Answer 7

Single long extension down which a signal travels

Question 8

Axon endings

Answer 8

Transmit a signal to next cell

Question 9

Myelin sheath

Answer 9

Insulating outer layer of axon

Question 10

Neuroglial cells

Answer 10

Schwann cells; support and protect neurons

Question 11

Action potential

Answer 11

Nerve impulse; sudden reversal in the charge difference across membrane, followed by the restoration of original charge difference

Question 12

During rest, how do the charges of a neuron differ?

Answer 12

The inner surface of membrane is more negatively charged that the outer surface

Question 13

What ion has a high concentration on the inside of a neuron?

Answer 13

Potassium

Question 14

What ion has a high concentration on the outside of a neuron?

Answer 14

Sodium

Question 15

Resting potential

Answer 15

Charge differences across membrane of a neuron which results from the unequal distribution of ions

Question 16

Depolarization

Answer 16

Signal causes sodium ion gates to open and sodium rushes into a nerve cell

Question 17

Repolarization

Answer 17

Potassium ion gates open and potassium ions rush out; pumps redistribute ions

Question 18

Refractory period

Answer 18

Brief instant immediately after an action potential occurs in which a neuron cannot be stimulated again for a short period

Question 19

Synapse

Answer 19

Junction between a neuron and another neuron

Question 20

Neurotransmitters

Answer 20

Chemicals that carry signals between neurons

Question 21

Excitatory synapse

Answer 21

Causes increase in activity of postsynaptic cell (increased likelihood of action potential)

Question 22

Inhibitory synapse

Answer 22

Causes decrease in activity of postsynaptic cell (decreases likelihood of action potential)

Question 23

Once neurotransmitters are used, they are removed by…

Answer 23

• enzymes

- protein pumps (return to presynaptic neuron for reuse)

Question 24

Neuron

Answer 24

Nerve cell; generates and transmits information