Week 1 - Quiz

Question 1

At which region of a neuron does signaling change from graded potentials to action potentials?

Answer 1

Axon Hillock

Question 2

What ions(s) is or are involved in EPSPs?

Answer 2

Both Na+ influx and K+ efflux, but sodium movement is much greater.

Question 3

What type of channel will NOT be part of our initial studies of basic action potentials BUT is involved in the sensation of sound?

Answer 3

Mechanically gated channels.

Question 4

What statement does NOT apply to the process of releasing neurotransmitters?
a. Vesicles use exocytosis to release neurotransmitter.
b. Neurotransmitters are released from the dendrites.
c. Neurotransmitters are specific to the synapse (meaning that we have more than one type in the nervous system).
d. The action potential allows voltage sensitive calcium channels at the axon terminal

Answer 4

B. Neurotransmitters are released from the dendrites.

Question 5

Neurons that carry impulses to glands or muscles are called?

Answer 5

Efferent Neurons

Question 6

What period of an action potential refers to when no added stimulus could cause another action potential to occur because the neuron is
currently involved in sending an action potential?

Answer 6

Absolute Refractory Period

Question 7

Voltage-sensitive channels on a neuron respond to which stimuli?
a. Depolarization associated with the initial stimulus OR the action potential itself.
b. Neurotransmitter binding to these channels.

Answer 7

A.

Question 8

What cell type insulates axons in the central nervous system?

Answer 8

Oligodendrocytes.

Question 9

What type of signal in a neuron is ‘all or none’?

Answer 9

Action Potentials

Question 10

Which cell type aids motion of the cerebrospinal fluid?

Answer 10

Ependymal cells.

Question 11

What is a subthreshold depolarization?

Answer 11

A stimulus that causes depolarization, but never reaches -55 mV (e.g., -57 is maximum reached).

Question 12

Do action potentials rely on summation? Meaning, must summation occur first in order to cause an action potential.

Answer 12

Yes

Question 13

How do we code for the variation of intensity of stimuli in the nervous system? (e.g., strong smells versus faint smells).

Answer 13

We send more frequent or less frequent action potentials close together in time.

Question 14

The site of graded potential conduction would be where on a neuron?

Answer 14

Dendrites AND cell bodies.

Question 15

What feature is associated with the postsynaptic membrane? This week’s homework will help with this question.
a. Location where exocytosis is involved.
b. Location that releases neurotransmitters.
c. Location of receptors for neurotransmitters.
d. Location where calcium ions enter.
e. Also referred to as the presynaptic neuron.

Answer 15

C

Question 16

What form of summation occurs when a single presynaptic neuron signals the postsynaptic neuron repeatedly in rapid succession?

Answer 16

Temporal Summation

Question 17

What structure of the neuron allows conduction of an action potential that will eventually lead to release of neurotransmitter?

Answer 17

Axon

Question 18

Chemically gated channels are found where on the neuron.

Answer 18

Dendrites

Question 19

The fatty sheath surrounding some nerve fibers is called.

Answer 19

Myelin

Question 20

What is a normal threshold for a neuron?

Answer 20

-55mV

Question 21

The cation with high concentration outside of cells that is important to initiating an action potential is…

Answer 21

Sodium

Question 22

Neurons that carry impulses toward the central nervous system (CNS) are called?

Answer 22

Afferent Neurons

Question 23

Nodes of Ranvier are found where on the neuron.

Answer 23

Axons of myelinated neurons.

Question 24

What structure maintains OR resets resting membrane potential after an action potential?

Answer 24

Na+/K+ pump.

Question 25

Consider a scenario where two separate presynaptic neurons innervate a postsynaptic neuron. If the two presynaptic neurons fire at the
exact same time and intensity, but one sends an IPSP and the other sends an EPSP what is likely to happen in the postsynaptic neuron?

a. The EPSP will dominate, and the postsynaptic neuron will be excited.

b. The incoming IPSP and EPSP will cancel each other out (spatial summation) and the postsynaptic neuron will not send an
action potential.

c. The IPSP will dominate, and the postsynaptic neuron will be inhibited.

Answer 25

B

Question 26

Graded potentials come in two forms. Which form is associated with depolarization of the neuron?

Answer 26

EPSPs

Question 27

If a neuron experiences EPSPs does that mean the neuron will send action potentials?

Answer 27

It depends upon whether threshold is reached at the axon hillock.

Question 28

Nodes of Ranvier would be associated with what pattern of action potential conduction.
a. Continuous conduction.
b. Saltatory conduction.

Answer 28

B. saltatory conduction

Question 29

Identify the true statement regarding the autonomic nervous system (ANS).
a. It is part (a branch of) the central nervous system.
b. It is an afferent branch (meaning sensory) of the peripheral nervous system.
c. It is one branch of the efferent nervous system (meaning motor).
d. None of the listed options is correct.
e. It is also known as the Somatic nervous system.

Answer 29

C

Question 30

What cell type provides most of the structural support for the CNS and helps create the blood brain barrier?

Answer 30

Astrocytes

Question 31

Which cell type is NOT a neuroglial cell?
a. Neurons.
b. Schwann cells.
c. Oligodendrocytes.
d. Ependymal cells.
e. Astrocytes.

Answer 31

a. Neuron

Question 32

What cell type has a neurilemma?
a. Astrocytes.
b. Neurons.
c. Ependymal cells.
d. Schwann cells.
e. Oligodendrocytes.

Answer 32

d. Schwann cells

Question 33

Saltatory conduction occurs where on a neuron?
a. Myelinated neurons.
b. Synapse.
c. Dendrites.
d. Unmyelinated neurons.
e. Cell body.

Answer 33

a. Myelinated Neurons

Question 34

What ion(s) is or are involved in IPSPs?
a. Cl- influx.
b. Na+ influx.
c. K+ efflux.
d. K+ efflux OR Cl- influx.
e. K+ efflux and Na+ influx.

Answer 34

D

Question 35

The component of the neuron that facilitates ‘integration’ or the processing of incoming signals is?’

Answer 35

Cell Body

Question 36

What neuron diameter will lead to faster conduction velocity for an action potential?
a. 1 to 5 micrometers.
b. Diameter of the axon does not impact conduction velocity.
c. 0.2 to 1.5 micrometers.
d. 13 to 28 micrometers.
e. 6 to 12 micrometers.

Answer 36

D

Question 37

Which cell type CANNOT be part of the central nervous system (CNS)?
a. Oligodendrocytes.
b. Astrocytes.
c. Schwann cells.
d. Neurons.
e. Ependymal cells.

Answer 37

c. Schwann cells

Question 38

When one presynaptic neuron innervates multiple postsynaptic neurons what type of circuit is this?
a. Integration circuit.
b. Diverging circuit.
c. Reciprocal inhibitory circuit.
d. Converging circuit.

Answer 38

b. Diverging circuit.

Question 39

Consider the events of an action potential (imagine the graph to help you). What option would be the last to occur?
a. Hyperpolarization occurs.
b. Depolarization occurs.
c. Stimulus occurs.
d. Sodium channels open.
e. Potassium channels open.

Answer 39

a. Hyperpolarization occurs.

Question 40

What type of neuron signal becomes weaker the farther it travels?
a. Graded potentials.
b. Action potentials.

Answer 40

a. Graded potentials.

Question 41

Do you find mitochondria in the region of the axon terminals of neurons?

Answer 41

yes

Question 42

Relative refractory period would correspond best to which aspect of an action potential?

a. The time between the stimulus and initiation of the depolarization phase.
b. The later portion of repolarization and hyperpolarization when the action potential is mostly accomplished.
c. The time when fast sodium channels close.
d. Only after hyperpolarization ends and resting membrane potential is completely restored.

Answer 42

b. The later portion of repolarization and hyperpolarization when the action potential is mostly accomplished.