Question 1

Which of the following describes the excitatory postsynaptic potential?
A) short distance hyperpolarization
B) short distance depolarization
C) opens K⁺ or Cl⁻ channels
D) moves membrane potential away from threshold

Accepted Answer

The excitatory postsynaptic potential (EPSP) is a localized, short-distance depolarization that brings the membrane potential closer to threshold, making it more likely that an action potential will be generated. EPSPs are typically caused by the opening of neurotransmitter-gated ion channels that allow for the influx of positively charged ions, such as Na+ or Ca2+, which depolarize the membrane.

Question 2

Neuroglia found in the CNS that bind axons and blood vessels to each other are called ________.

Accepted Answer

The answer of Neuroglia found in the CNS that bind...

Question 3

Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane?
A) Specific sodium gates will open.
B) Specific potassium gates will open.
C) Sodium gates will open first, then close as potassium gates open.
D) A single type of channel will open, permitting simultaneous flow of sodium and potassium.

Accepted Answer

The answer of Which of the following will occur when...

Question 4

Immediately after an action potential has peaked, which cellular gates open?
A) sodium
B) chloride
C) calcium
D) potassium

Accepted Answer

Immediately after an action potential has peaked, the potassium gates (K+) open, allowing for the outward movement of potassium ions and repolarization of the cell membrane.

Question 5

A second nerve impulse cannot be generated until ________.
A) the membrane potential has been reestablished
B) the Na ions have been pumped back into the cell
C) proteins have been resynthesized
D) all sodium gates are closed

Accepted Answer

After a nerve impulse, the membrane potential of a neuron needs to be reestablished before another impulse can be generated. This occurs through the action of the sodium-potassium pump, which pumps sodium ions out of the cell and potassium ions into the cell, restoring the resting membrane potential. Once this is complete, another nerve impulse can be generated. The other options (B, C, D) are not necessary for a second nerve impulse to be generated.

Question 6

Which of the following is not True of graded potentials?
A) They are short-lived.
B) They can form on receptor endings.
C) They increase amplitude as they move away from the stimulus point.
D) They can be called postsynaptic potentials.

Accepted Answer

Graded potentials decrease in amplitude as they move away from the stimulus point. This is due to the passive spread of the electrical charge along the cell membrane, which gradually diminishes with distance.

Question 7

Which of the following neurotransmitters inhibits pain and is mimicked by morphine, heroin, and methadone?
A) acetylcholine
B) endorphin
C) serotonin
D) nitric oxide

Accepted Answer

Endorphins inhibit pain and are mimicked by morphine, heroin, and methadone, which are all opioids that bind to the same receptors as endorphins. Acetylcholine, serotonin, and nitric oxide do not have significant roles in pain modulation.

Question 8

An inhibitory postsynaptic potential (IPSP) is associated with ________.
A) a change in sodium ion permeability
B) hyperpolarization
C) opening of voltage-regulated channels
D) lowering the threshold for an action potential to occur

Accepted Answer

An inhibitory postsynaptic potential (IPSP) is associated with hyperpolarization, which means the membrane potential becomes more negative and therefore less likely to reach the threshold for an action potential. This is accomplished by opening chloride channels or increasing potassium ion efflux, which counters the depolarizing effects of any excitatory postsynaptic potentials (EPSPs). The change in sodium ion permeability and voltage-regulated channels are associated with EPSPs. Lowering the threshold for an action potential to occur is not associated with IPSPs.

Question 9

What mechanism is responsible for axonal transport?

Accepted Answer

The answer of What mechanism is responsible for axonal transport?...

Question 10

Potentials that are short-lived, local changes in membrane potential that can be either depolarized or hyperpolarized are called ________ potentials.

Accepted Answer

The answer of Potentials that are short-lived, local changes in...

Question 11

If a motor neuron in the body were stimulated by an electrode placed about midpoint along the length of the axon ________.
A) the impulse would move to the axon terminal only
B) muscle contraction would occur
C) the impulse would spread bidirectionally
D) the impulse would move to the axon terminal only, and the muscle contraction would occur

Accepted Answer

When a motor neuron is stimulated at the midpoint of the axon, the action potential can propagate in both directions from the point of stimulation, leading to bidirectional impulse spread.

Question 12

The synapse more common in embryonic nervous tissue than in adults is the ________.

Accepted Answer

The answer of The synapse more common in embryonic nervous...

Question 13

Which of the following is True about the movement of ions across excitable living membranes?
A) Ions always move actively across membranes through leakage channels.
B) Ions always move passively across membranes.
C) Sodium gates in the membrane can open in response to electrical potential changes.
D) Ions always move from an area of higher concentration to an area of lower concentration

Accepted Answer

The movement of ions across excitable living membranes can be both passive and active. Sodium gates in the membrane can open in response to electrical potential changes, allowing for passive movement of sodium ions into the cell. Additionally, active transport mechanisms such as ion pumps and channels can move ions against their concentration gradients. Leakage channels do not require energy and are always open, but not all ions move exclusively through leakage channels. Lastly, while ions often move from areas of higher concentration to areas of lower concentration, this is not always the case and is dependent on various factors such as membrane potential and electrochemical gradients.

Question 14

What is the role of microglial cells and why are they so important in the CNS?

Accepted Answer

The answer of What is the role of microglial cells...

Question 15

In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? The interior is ________.
A) positively charged and contains less sodium
B) negatively charged and contains less sodium
C) negatively charged and contains more sodium
D) positively charged and contains more sodium

Accepted Answer

The interior surface of a cell membrane of a resting (nonconducting) neuron is negatively charged due to the presence of negatively charged proteins and ions such as chloride (Cl-) and organic ions. Additionally, the interior contains less sodium compared to the external environment, which has a higher concentration of sodium ions.

Question 16

That part of the nervous system that is voluntary and conducts impulses from the CNS to the skeletal muscles is the ________ nervous system.

Accepted Answer

The answer of That part of the nervous system that...

Question 17

When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________.
A) postsynaptic potential
B) excitatory potential
C) action potential
D) generator potential

Accepted Answer

When a sensory neuron is excited by some form of energy, the resulting graded potential is called a generator potential. Postsynaptic potentials refer to the graded potentials that occur in postsynaptic neurons in response to neurotransmitter release from presynaptic neurons. Excitatory potentials are a type of postsynaptic potential that depolarizes the neuron and make it more likely to fire an action potential. Action potentials are the electrical signals that travel down the axon of a neuron.

Question 18

When one or more presynaptic neurons fire in rapid order it produces a much greater depolarization of the postsynaptic membrane than would result from a single EPSP; this event is called ________ summation.

Accepted Answer

The answer of When one or more presynaptic neurons fire...

Question 19

When information is delivered within the CNS simultaneously by different parts of the neural pathway, the process is called ________ processing.

Accepted Answer

The answer of When information is delivered within the CNS...

Question 20

A chemical messenger that does not directly cause ESPSs or IPSPs but does affect the strength of synaptic transmission is a ________.

Accepted Answer

The answer of A chemical messenger that does not directly...

Quiz 11: Fundamentals of the Nervous System and Nervous Tissue

Which of the following describes the excitatory postsynaptic potential?

Neuroglia found in the CNS that bind axons and blood vessels to each other are called ________.

Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane?

Immediately after an action potential has peaked, which cellular gates open?

A second nerve impulse cannot be generated until ________.

Which of the following is not True of graded potentials?

Which of the following neurotransmitters inhibits pain and is mimicked by morphine, heroin, and methadone?

An inhibitory postsynaptic potential (IPSP) is associated with ________.

What mechanism is responsible for axonal transport?

Potentials that are short-lived, local changes in membrane potential that can be either depolarized or hyperpolarized are called ________ potentials.

If a motor neuron in the body were stimulated by an electrode placed about midpoint along the length of the axon ________.

The synapse more common in embryonic nervous tissue than in adults is the ________.

Which of the following is True about the movement of ions across excitable living membranes?

What is the role of microglial cells and why are they so important in the CNS?

In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? The interior is ________.

That part of the nervous system that is voluntary and conducts impulses from the CNS to the skeletal muscles is the ________ nervous system.

When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________.

When one or more presynaptic neurons fire in rapid order it produces a much greater depolarization of the postsynaptic membrane than would result from a single EPSP; this event is called ________ summation.

When information is delivered within the CNS simultaneously by different parts of the neural pathway, the process is called ________ processing.

A chemical messenger that does not directly cause ESPSs or IPSPs but does affect the strength of synaptic transmission is a ________.