Question 1

Action potentials result from:
A)an inflow of positively charged sodium ions.
B)an outflow of positively charged potassium ions.
C)an inflow of potassium followed by an outflow of sodium.
D)an inflow of sodium followed by an outflow of potassium.

Accepted Answer

Action potentials result from an initial inflow of positively charged sodium ions, followed by an outflow of positively charged potassium ions. This process generates an electrical impulse that travels along the axon of a neuron. Therefore, choice D, an inflow of sodium followed by an outflow of potassium, is the best option.

Question 2

When neurons communicate,
A)they do so in an electrical and chemical language.
B)they do so by touching one another,end to end.
C)they do so when an electrical potential "hops" between two cells.
D)they do so through a chemical neurotransmitter that travels down the axon.

Accepted Answer

Neurons communicate through a combination of electrical signals within the neuron and chemical signals (neurotransmitters) between neurons. This combination is often referred to as the electrical and chemical language of the brain.

Question 3

Stem cell research is exciting to scientists because it has the potential to:
A)help people recover from brain diseases like Alzheimer's disease.
B)help people to recover from spinal cord damage.
C)help people recover from brain injury.
D)all of the above.

Accepted Answer

Stem cells have the potential to differentiate into different tissues and cells in the body, including those in the brain and spinal cord. This means that stem cell research has the potential to benefit individuals with brain diseases, spinal cord damage, and brain injury.

Question 4

Researchers have found that:
A)in myelinated axons,the action potential at each point in the axon gives rise to a new action potential at the next point.
B)in unmyelinated axons,positively charged ions flow down the axon at a very fast rate,causing regeneration of the action potential at each node.
C)throughout life,unused synaptic connections are pruned away as cells or their branches die and are not replaced.
D)when a nerve impulse reaches the axon terminal's button-like tip,the action potential "hops" over to the receiving neuron's dendrites.

Accepted Answer

Unused synaptic connections are pruned throughout life, a process that helps optimize neural networks by removing unnecessary connections.

Question 5

A brief change in electrical voltage in the neuron in response to stimulation is called:
A)a node.
B)an action potential
C)a synaptic charge.
D)a neurotransmission.

Accepted Answer

A brief change in electrical voltage in the neuron in response to stimulation is called an action potential. The other options are not correct descriptions of this phenomenon. A node refers to specific points along the length of a neuron where the myelin sheath is interrupted. Synaptic charge is not a term commonly used in neuroscience. Neurotransmission refers to the process by which neurons communicate with one another through the release and reception of neurotransmitters.

Question 6

"Pruning" refers to:
A)a loss of dendrites and synaptic connections that occurs as we age.
B)a loss of dendrites and synaptic connections that occurs in certain degenerative diseases.
C)the death of neurons that results when synaptic connections are lost.
D)a loss of unused synaptic connections that results in a more efficient neural network.

Accepted Answer

Pruning refers to the elimination of unused or unnecessary synaptic connections between neurons, which results in a more efficient neural network. This process occurs naturally during brain development and continues throughout life, as the brain adapts to new experiences and learning. It is not necessarily associated with the loss of dendrites or synaptic connections that occur as a result of aging or certain degenerative diseases.

Question 7

When an action potential reaches the end of the axon terminal:
A)it hops across the synaptic cleft to the next neuron.
B)it reverses direction and returns to the cell body.
C)it causes synaptic vesicles to break open and release molecules of neurotransmitter.
D)it causes pores on the axon terminal to open and receive neurotransmitters from other neurons.

Accepted Answer

When an action potential reaches the end of the axon terminal, it causes synaptic vesicles to release molecules of neurotransmitter into the synaptic cleft. The neurotransmitter then binds to receptors on the next neuron, initiating a new action potential.

Question 8

Which of the following statements is true?
A)Injured or damaged neurons in the central nervous system can never regenerate.
B)No new neurons are produced in the central nervous system after infancy.
C)Neurogenesis occurs in the spinal cord but not in the brain.
D)Recent research suggests that stem cells in the brain may be able to generate new neurons throughout life.

Accepted Answer

Recent research has shown that stem cells in the brain are capable of generating new neurons throughout life, a process called neurogenesis. While the ability of neurons to regenerate in the central nervous system is limited, the discovery of neurogenesis has opened up new possibilities for treating brain injuries and degenerative diseases. Option A is incorrect because damaged neurons can regenerate to a limited extent under certain conditions. Option B is incorrect because neurogenesis continues to occur in certain regions of the brain, including the hippocampus, throughout adulthood. Option C is incorrect because neurogenesis has been observed in both the spinal cord and the brain.

Question 9

Which of the following is NOT included in the synapse?
A)the axon terminal
B)the axon of the receiving cell
C)the synaptic cleft
D)the receptor sites in the membrane of the receiving cell

Accepted Answer

The axon of the receiving cell is not part of the synapse. The synapse only consists of the axon terminal of the sending cell, the synaptic cleft, and the receptor sites in the membrane of the receiving cell. The axon of the receiving cell is separate and not directly involved in the transmission of signals between neurons.

Question 10

Neurons in a newborn's brain:
A)are densely spaced with complex connections.
B)are widely spaced,but immediately begin to form connections.
C)touch one another,end to end.
D)are twice as numerous as glial cells.

Accepted Answer

Neurons in a newborn's brain are widely spaced initially but quickly begin to form connections with other neurons. It takes time for the brain to develop complex neural networks and for neurons to become densely spaced with multiple connections.

Note: Option A could be true for adult brains but not necessarily for newborn brains. Option C is also incorrect as neurons do not touch each other directly. Option D is also incorrect as glial cells outnumber neurons in the brain.

Question 11

Nerve impulses travel more slowly in babies than in older children and adults because:
A)the infant does not have as many synaptic connections.
B)dendrites have not yet developed spines in infants.
C)axons are much shorter in infants.
D)the myelin sheaths on axons are not yet fully developed in infants.

Accepted Answer

Myelin sheaths are important for increasing the speed at which nerve impulses can travel along axons. In infants, these sheaths are not yet fully developed, leading to slower nerve impulse transmission.

Question 12

_______________ describes the brains ability to retain flexibility in adapting to new experiences.
A)Flexibility
B)Plasticity
C)Stability
D)Vulnerability

Accepted Answer

Plasticity refers to the brain's ability to change and adapt in response to new experiences. It allows the brain to reorganize itself by forming new neural connections and modifying existing ones, which is essential for learning and memory.

Question 13

The site where a nerve impulse is transmitted from one nerve cell to another is called the:
A)action potential.
B)myelinated axon.
C)precursor cell.
D)synapse.

Accepted Answer

The site where a nerve impulse is transmitted from one nerve cell to another is called the synapse. Option A, action potential, refers to the electrical signal that travels along the axon of a neuron. Option B, myelinated axon, refers to the type of nerve fiber that is insulated with myelin, which speeds up the transmission of nerve signals. Option C, precursor cell, refers to a cell that can develop into different types of cells, but is not specifically related to the transmission of nerve impulses in the nervous system.

Question 14

_______________ occurs when a brief change in electrical voltage takes place between the inside and the outside of an axon when a neuron is stimulated.
A)An action potential
B)Neurogenesis
C)Biofeedback
D)Plasticity

Accepted Answer

An action potential is the brief change in electrical voltage that occurs between the inside and the outside of an axon when a neuron is stimulated. It is the basic unit of communication in the nervous system. Neurogenesis refers to the development and growth of new neurons. Biofeedback is a technique used to monitor and control biological functions, such as heart rate or muscle tension. Plasticity refers to the brain's ability to change and adapt in response to experiences and environment.

Question 15

Daphne is unable to recall simple words the day after her stroke,but within a matter of months she is speaking normally again.This is due to:
A)progenitor cells.
B)myelination.
C)plasticity.
D)axonal regeneration.

Accepted Answer

Plasticity refers to the brain's ability to reorganize itself by forming new neural connections. In Daphne's case, plasticity allowed her brain to form new neural connections and pathways after her stroke, which enabled her to regain her ability to speak normally within a few months. Progenitor cells, myelination, and axonal regeneration may play roles in brain development and repair, but they are not the primary mechanisms responsible for Daphne's recovery in this case.

Question 16

Which of the following is true about synapses?
A)Each axon makes a synaptic connection with only one other neuron.
B)A single neuron may receive input from hundreds of other neurons.
C)Once a synaptic connection is formed,it will not be lost unless the neuron itself dies.
D)The network of synaptic connections can change throughout childhood,but stops changing at adolescence.

Accepted Answer

A single neuron can indeed receive input from hundreds or even thousands of other neurons.

Answer: C 
 Synaptic connections can be lost and new ones can form throughout an individual's life. However, once a synaptic connection is established, it tends to be relatively stable unless there is some kind of disease or injury that affects it.

Note: D is false - synaptic connections can continue to change throughout adulthood, not just childhood, through a process known as synaptic plasticity.

Question 17

In order to prepare for her psychology test,Jendaya writes key points on index cards in order to quiz herself on neuronal communication.Which of the following would NOT be found on her study cards?
A)A neuron's axon may have hundreds or even thousands of terminals and so the number of communication links in the nervous system runs into the trillions.
B)Throughout life,some unused synaptic connections are lost as cells or their branches die and are not replaced.
C)Nerve impulses travel more quickly in babies than in older children because with age comes neuronal degeneration.
D)When a nerve cell is stimulated,a change in electrical potential occurs between the inside and the outside of the cell.

Accepted Answer

Nerve impulses actually travel more quickly in older individuals due to the myelination process. Choice C is incorrect and would not be found on Jendaya's study cards.

Question 18

"Plasticity" means that:
A)synaptic connections can change throughout life.
B)neurons have a myelin sheath,similar to a plastic shell,that surrounds them.
C)axons,like soft plastic,are flexible and can bend around obstacles to make synaptic connections.
D)people can compensate for brain damage by learning new ways to do things.

Accepted Answer

Plasticity refers to the brain's ability to change and adapt throughout life, including the ability of synaptic connections between neurons to change or strengthen. Option B refers to the myelin sheath, which is not directly related to plasticity. Option C refers to the flexibility of axons, which can aid in plasticity but does not fully encompass the concept. Option D refers to the brain's ability to compensate for damage, which is a result of plasticity but does not fully define the term.

Question 19

Action potentials:
A)travel swiftly down axons with myelin and more slowly in axons without myelin.
B)travel swiftly down axons without myelin and more slowly in axons with myelin.
C)travel swiftly down dendrites with myelin and more slowly in dendrites without myelin.
D)travel swiftly down dendrites without myelin and more slowly in dendrites with myelin.

Accepted Answer

Action potentials travel swiftly down axons with myelin because the myelin acts as an insulator and allows the electrical signal to jump from one node of Ranvier to the next, increasing the speed of conduction. In axons without myelin, the action potential must propagate along the entire length of the axon, which makes the conduction slower.

Question 20

Throughout life,axons and dendrites continue to grow,and tiny projections on dendrites,called _______________ increase in size and number.
A)spines
B)axon terminals
C)precursor cells
D)stem cells

Accepted Answer

Axons and dendrites do continue to grow throughout life, but only the tiny projections on dendrites called spines increase in size and number. Axon terminals are the end points of axons where they make contact with other neurons or muscle cells. Precursor cells and stem cells are involved in the production of new neurons, but they do not directly contribute to the growth of axons and dendrites already in place.

Quiz 4: Exstintion: The Brain: Source of Mind and Self

Action potentials result from:

When neurons communicate,

Stem cell research is exciting to scientists because it has the potential to:

Researchers have found that:

A brief change in electrical voltage in the neuron in response to stimulation is called:

"Pruning" refers to:

When an action potential reaches the end of the axon terminal:

Which of the following statements is true?

Which of the following is NOT included in the synapse?

Neurons in a newborn's brain:

Nerve impulses travel more slowly in babies than in older children and adults because:

_______________ describes the brains ability to retain flexibility in adapting to new experiences.

The site where a nerve impulse is transmitted from one nerve cell to another is called the:

_______________ occurs when a brief change in electrical voltage takes place between the inside and the outside of an axon when a neuron is stimulated.

Daphne is unable to recall simple words the day after her stroke,but within a matter of months she is speaking normally again.This is due to:

Which of the following is true about synapses?

In order to prepare for her psychology test,Jendaya writes key points on index cards in order to quiz herself on neuronal communication.Which of the following would NOT be found on her study cards?

"Plasticity" means that:

Action potentials:

Throughout life,axons and dendrites continue to grow,and tiny projections on dendrites,called _______________ increase in size and number.