Chapter 11 Bio Problem Sets

Sodium potassium pumps will move ________ potassium ions into the cell for every ________ sodium ions that they move out of the cell.

2, 3

The resting potential of a neuron is approximately minus

70 millivolts.

Which of the following occurs first during an action potential?

A local disturbance triggers the resting voltage to exceed the threshold level.

Which statement is correct?

A motor unit will have multiple dendrites and a single axon that signals a muscle or gland.

When neurotransmitter breakdown is prevented by a product like sarin gas, which of the following will occur?

All of these choices.

Insufficient production of acetylcholine in the synapses of the brain, abnormal tangled neurons, andlarge deposits of beta amyloid are problems associated with:

Alzheimer's disease.

Which statement is false?

An action potential continues indefinitely until a quenching signal is released.

Which portion of the neuron specializes in sending a message?

Axon

Which of the following is not true regarding the sodium-potassium pump?

Due to actions of the sodium-potassium pump, the charge of the cytoplasm of a neuron is slightly more positive than the charge of the interstitial fluid surrounding it.

Which of the following concerning transport proteins in the neuron membrane is true?

Energy moves ions against the concentration gradient.

Which area of the brain is responsible for determining the strength of the heartbeat and the rhythm of breathing?

Medulla oblongata

Which neurological disorder is characterized by tremors, a loss of balance, and difficulty speaking? A head injury that results in the loss of consciousness increases the risk.

Parkinson's disease

What happens immediately following the closing of the sodium gates during an action potential?

Potassium ions leave the cell.

Which of the following is the first response a neuron makes to a stimulus?

Sodium ions enter the cell.

Which portion of the nervous system will directly relay commands to the skeletal muscles that are under voluntary control?

Somatic

Which branch of the neural system will cause an increase in heart rate, blood pressure and respiration during times of stress?

Sympathetic

Which of the following occurs during the absolute refractory period?

The neuron cannot generate an action potential.

Which of the following is a true statement regarding the synapse?

The synaptic cleft is a fluid-filled gap located between the presynaptic neuron and the postsynaptic neuron.

Which of the following is NOT true concerning sensory neurons?

They lie in the pathway between the interneurons and motor neurons.

An action potential is brought about by

a local change in membrane permeability caused by a greater-than-threshold stimulus.

Functionally speaking, a nerve impulse is

a series of changes in membrane potentials.

For sodium to accumulate rapidly in a neuron,

a stimulus above the threshold must open sodium gates in an accelerating manner.

An abrupt reversal in the electric gradient across the plasma membrane is called a(n) ________.

action potential

During the passage of a nerve impulse

all of these

Neuroglial cells

all of these

When a neuron is at rest

all of these

Oligodendrocytes are similar to Schwann cells in that they:

are a type of neuroglial cell.

Transmitter substances

are expelled from the presynaptic cells and interact with membrane receptors of thepostsynaptic cells.

The single long process that extends from a typical motor nerve cell is the

axon

Which is a junction between two neurons?

chemical synapse

Which of the following events associated with the transmission of an impulse across a synapse occurs last?

chemically gated channels for sodium open in the postsynaptic membrane

Within a single neuron, the direction an impulse follows is

dendrite >>> cell body >>> axon.

The principal job of the human nervous system is to

facilitate communication among the body systems.

Chronic Traumatic Encephalopathy (CTE) is characterized by a brain pathology that includes both beta-amyloidplaques and neurofibrillary tangles.

false

The nucleus and most of the organelles of a neuron are located in the dendrites.

false

Disturbances in sensory neurons will result in an action potential if the

graded stimulus reaches a trigger zone.

Active transport

helps to establish the resting potential of a neuron, counters the process of diffusion, andallows transport of atoms across the plasma membrane of the neuron against theconcentration gradient.

If a nerve impulse is traveling from the central nervous system to the organs of the body, the impulse would be traveling on a:

motor neuron.

The phrase "all or nothing," used in conjunction with discussion about an action potential, means that

nothing can stop the action potential once the threshold is reached.

When an impulse passes from one neuron to the next, it

passes from axon to dendrite.

During an action potential the loss of _____________ causes the membrane potential to decline below the resting potential.

potassium

At rest, a nerve cell has a high concentration of __________ inside and a high concentration of __________ outside.

potassium; sodium

The recovery time from the passage of a nerve impulse is called the

refractory period.

During which of the following phases of an action potential do the sodium channels close and potassium channels open, releasing potassium from the neuron?

repolarization

During the all - or - nothing spike __________ ions rush into the axon to cause it to become positive relative to the outside.

sodium

The membrane-bound enzyme system that restores and maintains the resting membrane potential is which of the following pumps?

sodium-potassium

Amyotrophic lateral sclerosis (ALS is a disease that results from nerve damage) in the:

spinal cord.

The occurrence of an action potential can best be compared to a

switch to turn a lamp on and off.

Which of the following processes is depicted in the above diagram?

synaptic transmission

The heavily phosphorylated (hyper-phosphorylated) protein found in both Alzheimer's Disease and CTE is known as:

tau protein

The basic unit of the nervous system is

the neuron.

Once a threshold is reached,

the opening of sodium gates and the accompanying flow of sodium ions is an example of positive feedback.

During the recovery period between action potentials,

the sodium gates are shut and the potassium gates are opened.

A student noticed that every time he smelled a certain perfume in the hallway, itreminded him of his mother. This is due largely to the activity of the limbic system.

true

The absolute refractory period characteristic of neurons is important in ensuring thataction potentials travel in only one direction. (KNOW FOR FINAL EXAM.)

true

The two subdivisions of the nervous system are the central nervous system and theperipheral nervous system.

true

True or False. Fentanyl is a particularly dangerous opioid because this compound is lipophilic, and more readilycrosses the blood-brain barrier than do other opioids.

true

Which of the following terms most accurately describes the cellular activity associated with the actual passage of a nerve impulse?

wave of depolarization