Question 1

An action potential involves the temporary ________ through an axon membrane.

Accepted Answer

During an action potential, there is a rapid influx of positively charged ions (usually sodium ions) into the axon, which causes depolarization of the membrane potential. This depolarization then triggers the opening of voltage-gated ion channels and the outflow of positively charged ions (usually potassium ions), leading to repolarization of the membrane potential.

Question 2

The speed at which a neural impulse travels is increased when the axon is encased by a(n)

Accepted Answer

Myelin sheath serves as an insulating layer around the axon, allowing for faster transmission of neural impulses.

Question 3

A brief electrical charge that travels down the axon of a neuron is called the

Accepted Answer

A brief electrical charge that travels down the axon of a neuron is called the action potential. The synapse is the gap between two neurons where communication occurs, an agonist is a drug or chemical that enhances the activity of a neurotransmitter, and the refractory period is the period of time after an action potential when the neuron is unable to fire again.

Question 4

Following depolarization,the sodium/potassium pump transports ________ ions ________ a neuron.

Accepted Answer

The sodium/potassium pump is responsible for restoring the distribution of ions to their resting state following depolarization. This pump works to move positively charged sodium ions out of the neuron and positively charged potassium ions into the neuron, thus restoring the negative resting potential inside the neuron. Therefore, the correct choice is C) positively charged;out of.

Question 5

Degeneration of the myelin sheath results in

Accepted Answer

Degeneration of the myelin sheath is a characteristic feature of multiple sclerosis (MS), an autoimmune disorder that affects the central nervous system. MS results in damage to the myelin sheath, which leads to nerve signal disruptions that can result in a range of symptoms, including fatigue, weakness, tingling, numbness, vision problems, and difficulties with coordination, balance, and speech.

Question 6

Which brain cells play a role in learning and memory by communicating with neurons?

Accepted Answer

Glial cells play a role in learning and memory by communicating with neurons. They aid in the formation of synapses between neurons, regulate neurotransmitters, and provide support for neurons. Endorphins are involved in pain modulation and mood regulation. Agonists are chemicals that bind to a receptor and activate it. Myelin cells form a sheath around axons to improve conduction of neural impulses, but do not directly communicate with neurons involved in learning and memory.

Question 7

A resting axon's fluid interior has a mostly negative charge thanks to the presence of large ________ ions.

Accepted Answer

The presence of large protein ions, such as negatively charged amino acids, within the resting axon's fluid interior creates a negative charge, known as the resting membrane potential. Sodium ions play a role in depolarization, not creating the resting membrane potential. Serotonin and dopamine are neurotransmitters, not ions present in the fluid interior of the axon.

Question 8

The resting potential of an axon results from the fact that an axon membrane is

Accepted Answer

The resting potential of an axon, which is the electrical charge across the axon membrane when it is not active, is a result of the selective permeability of the membrane. The membrane allows certain ions (such as potassium and sodium) to pass through more easily than others, which creates a difference in charge between the inside and the outside of the axon. This difference in charge is what creates the resting potential. None of the other options listed contribute to the resting potential.

Question 9

Mathematical computations by a computer are faster than your quickest mathematical computations because the top speed of a neural impulse is about ________ times slower than the speed of electricity through the wired circuitry in a computer.

Accepted Answer

The top speed of a neural impulse is about 100 meters per second while the speed of electricity through the wired circuitry in a computer is roughly 300,000,000 meters per second. Therefore, the speed of electricity through a computer is about 3 million times faster than the speed of a neural impulse.

Question 10

A state in which the fluid outside an axon has a mostly positive charge and the fluid inside the axon has a mostly negative charge is called

Accepted Answer

The state in which the fluid outside an axon has a mostly positive charge and the fluid inside the axon has a mostly negative charge is called the resting potential. This is the baseline electrical state of the neuron when it is not actively sending a signal (action potential), and is maintained through the action of ion channels in the neuron's cell membrane.

Question 11

The minimum level of stimulation required to trigger a neural impulse is called the

Accepted Answer

The minimum level of stimulation required to trigger a neural impulse is called the threshold. A stimulus must reach a certain level of intensity in order to generate an action potential, which is the electrical signal that travels down a neuron. Below the threshold, the neuron will not fire, but above the threshold, it will fire with the same intensity every time.

Question 12

The depolarization of a neural membrane creates a(n)

Accepted Answer

Depolarization is the process where the inside of the neural membrane becomes more positively charged, which triggers an action potential, a brief electrical signal that travels down the length of the neuron.

Question 13

A myelin sheath is a

Accepted Answer

A myelin sheath is a layer of fatty tissue that surrounds and insulates the axons of some nerve cells. This insulation allows for faster and more efficient transmission of electrical impulses along the axon.

Question 14

One function of glial cells is to

Accepted Answer

Glial cells, specifically astrocytes, play a role in providing nutrients and support to neurons. They help regulate the chemical environment and transport nutrients such as glucose and oxygen to neurons. While glial cells can also play a role in modulating neural impulse speed, mimicking neurotransmitters, and stimulating hormone production, providing nutrients to neurons is considered one of their primary functions.

Question 15

An action potential is generated by the movement of ________ through an axon membrane.

Accepted Answer

An action potential is generated by the movement of positively charged ions, such as sodium (Na+) and potassium (K+), through an axon membrane.

Question 16

Gerald has experienced increasing difficulties with muscle weakness,motor coordination,and body balance,which physicians have attributed to multiple sclerosis.These symptoms are most likely to be directly linked with the degeneration of

Accepted Answer

The symptoms described in the passage, including muscle weakness, motor coordination difficulties, and body balance issues, are all characteristic of multiple sclerosis, which is a disease caused by the degeneration of the myelin sheath. The myelin sheath is a protective covering that surrounds nerve fibers and helps to facilitate the transmission of signals between neurons. When this sheath is damaged or destroyed, as in the case of multiple sclerosis, it can lead to a variety of neurological symptoms.

Question 17

Neurons are surrounded by ________,which guide neural connections and mop up ions and neurotransmitters.

Accepted Answer

Glial cells surround neurons and perform various functions including guiding neural connections and cleaning up ions and neurotransmitters. Endorphins and hormones are not directly involved in this process, and agonists are substances that bind to receptors and activate them, which is not the function of glial cells.

Question 18

The loss of an electrical charge difference between the inside and outside of an axon membrane is called

Accepted Answer

The answer of The loss of an electrical charge difference...

Question 19

Neurons generate electricity from a chemical process involving the exchange of

Accepted Answer

Neurons generate electricity through an electrochemical process involving the exchange of ions, particularly sodium and potassium ions, across the cell membrane.

Question 20

Excitatory signals to a neuron must exceed inhibitory signals by a minimum intensity in order to trigger

Accepted Answer

Excitatory signals must exceed inhibitory signals by a minimum intensity to trigger an action potential. This is because an action potential is an all-or-nothing response that occurs when the electrical charge of the neuron reaches a certain threshold. Reuptake is the process of neurotransmitter removal from the synaptic cleft, and selective permeability is the property of a membrane allowing only certain substances to pass through. The refractory period is the time during which a neuron cannot generate another action potential. While inhibitory signals can prevent the firing of an action potential, they cannot trigger one.

Quiz 2: The Biology of Behavior