Chapter 2: Communication within the Nervous System

Question 1

Scientists estimate that there are about __ neurons in the brain

Answer 1

D. 100 billion

Question 2

In the nervous system, which of the following types of cells is the MOST numerous.

Answer 2

A. Glia

Question 3

The nucleus of a neural cell is located in the

Answer 3

C. Soma

Question 4

A neuron that transmits information between the central nervous system and a muscle is called a

Answer 4

A. Motor neuron

Question 5

A __ neuron has an axon and several dendrites projecting away from the cell body

Answer 5

B. Multipolar

Question 6

Which of the following statements regarding interneurons is TRUE

Answer 6

C. They may have no axon at all.

Question 7

The neural membrane is selectively permeable to all of the following substances EXCEPT

Answer 7

C. Oxygen

Question 8

When a neuron is at rest, __ ions are more plentiful outside of the cell

Answer 8

A. NA+

Question 9

The TYPICAL resting potential of a neuron is

Answer 9

D. -70mV

Question 10

When the cell is at rest, K+ ions are strongly attracted across the cell membrane

Answer 10

B. Mostly because of the force of dillusion

Question 11

All of the following are able to pass through the membrane under certain conditions EXEPT

Answer 11

D. A-

Question 12

Which of the following statements regarding the sodium-potassium pump is FALSE

Answer 12

C. It pumps sodium into the cell

Question 13

Neurons undergo depolarization when

Answer 13

B. NA+ ions enter the cell

Question 14

Depolarization is MOST similar to

Answer 14

A. Hypopolarization

Question 15

When the neuron is at resting potential, NA+ ions are strongly attracted across the cell membrane because of

Answer 15

C. Both electrostatic pressure and diffusion

Question 16

A neuron will fire an action potential when it is

Answer 16

D. Depolarized to its threshold

Question 17

The outflow of K+ ions during an action potential results in

Answer 17

B. Hyperpolarization

Question 18

The action potentials generated by a specific neuron

Answer 18

A. are the same strength

Question 19

Which of the following statements regarding the absolute refractory period is FALSE

Answer 19

A. The potassium channels are closed and cannot be opened

Question 20

During the relative refractory period

Answer 20

D. All of the above - the neuron is hyperpolarized, a stronger stimulus may result in another action potential, potassium channels are open

Question 21

The maximum speed at which a neuron can conduct an action potential seems to be about

Answer 21

C. 120 m/s

Question 22

The __ the axon, the __ the action potential

Answer 22

B. Thicker, faster

Question 23

In the central nervous system, myelin is formed by

Answer 23

C. Oligodendrocytes

Question 24

in myelinated axons,

Answer 24

B. Action potentials occur only at the nodes of Ranvier.

Question 25

Myelination results in all of the following EXCEPT

Answer 25

A. Increased capacitance

Question 26

Which of the following was not mentioned as a function of the glial cells

Answer 26

D. Transmitting action potentials

Question 27

Who discovered that neurons are separate cells and are NOT in contact with each other

Answer 27

A. Ramon y Cajal

Question 28

Who demonstrated that synaptic transmission is chemical?

Answer 28

C. Loewi

Question 29

When an action potential reaches an axon terminal, __ ions enter the cell and trigger the release of the neurontransmitter

Answer 29

D. Ca+

Question 30

Fast acting receptors involved in muscle activity and sensory processing are referred to as

Answer 30

C. ionotropic

Question 31

Under normal circumstances, the neurotransmitter molecules released by a single neuron can do all the following EXCEPT

Answer 31

C. Trigger an action potential

Question 32

An IPSP will occur if

Answer 32

D. Potassium channels open and chloride channels open.

Question 33

Action potentials are first produced

Answer 33

A. At the axon hillock

Question 34

In order for spatial summation to occur.

Answer 34

B. Several EPSP's and/or IPSP's must arrive at the same time from different inputs.

Question 35

If a neuron has a resting potential of -70 mV and a threshold of -60 mV, which of the following combinations of simultaneous postsynaptic potentials will result in an action potential

Answer 35

B. 50 EPSP's of .5 mV each and 20 IPSP's of 05 mV each

Question 36

Acetylcholine is removed from the synapse by

Answer 36

C. Enzymatic deactivation

Question 37

Neurotransmitters interact with receptor sites like a __

Answer 37

A. Key into a lock

Question 38

Which of the following statements regarding nicotinic receptors is FALSE

Answer 38

A. They are inhibitory

Question 39

Regarding the types of neurotransmitters that a neuron can release, which of the following statements is FALSE.

Answer 39

B. There are neurons that are incapable of releasing any neurotransmitters at all.

Question 40

Which of the following is an antagonist at acetylcholine receptors?

Answer 40

C. Naloxone

Question 41

In an artificial neural network, MOST of the processing occurs in which layer of neurons?

Answer 41

B. Hidden

Question 42

The ability of neurons to carry information is increased by

Answer 42

D. Varied time intervals of neural bursts

Question 43

The solution to the problem that chains of single neurons are inadequate to handle the brain's tasks is

Answer 43

A. Neural networks.