Question 1

A neuron's reaction of either firing at full strength or not firing at all is described as

Accepted Answer

The all-or-none response refers to the fact that a neuron will either fire an action potential (at full strength) or not fire at all, depending on the strength of the incoming signals it receives.

Question 2

A synapse is a(n)

Accepted Answer

A synapse is a junction between a sending neuron and a receiving neuron where communication occurs through the release of neurotransmitters. Choice A is incorrect because muscle contractions are triggered by neurotransmitters, not by synapses. Choice B is incorrect because not all synapses involve automatic responses. Choice D is incorrect because neural cables containing many axons are called nerves, not synapses.

Question 3

The axon of a sending neuron is separated from the dendrite of a receiving neuron by a

Accepted Answer

The gap between the axon of a sending neuron and the dendrite of a receiving neuron is called the synaptic gap or synaptic cleft. This is where neurotransmitters are released from the sending neuron and bind to receptors on the receiving neuron, allowing for communication between the two neurons. The other options (myelin sheath, neural network, and glial cell) are not directly involved in this synaptic communication process.

Question 4

An undersupply of the major inhibitory neurotransmitter known as ________ is linked to seizures.

Accepted Answer

GABA (gamma-aminobutyric acid) is a major inhibitory neurotransmitter that helps regulate brain activity. An undersupply of GABA can result in overstimulation of the brain and lead to seizures.

Question 5

The ______ occurs at an electrical charge of about -70 mV and the ______ occurs at a charge of about +40 mV.

Accepted Answer

The resting potential occurs at about -70 mV, which is the stable, negative charge of an inactive neuron. The action potential occurs at about +40 mV, which is the peak of the electrical charge during the rapid depolarization phase of a neuron's firing.

Question 6

Which neurotransmitter plays the most direct role in learning and memory?

Accepted Answer

Acetylcholine plays a critical role in learning and memory processes in the brain. It is involved in forming new memories and in the retrieval of previously learned information. Dysfunction of the acetylcholine system is linked to memory impairments seen in conditions such as Alzheimer's disease.

Question 7

An undersupply of serotonin is most closely linked to

Accepted Answer

Serotonin is a neurotransmitter responsible for regulating mood and emotions. An undersupply of serotonin has been closely linked to depression, as it can lead to feelings of sadness, anxiety, and low motivation.

Question 8

The number of neurotransmitter molecules located within a specific synaptic gap would most clearly be reduced by

Accepted Answer

Reuptake is the process by which neurotransmitter molecules are taken back into the presynaptic neuron, which reduces the amount of neurotransmitter in the synaptic gap. This can lead to a decrease in synaptic transmission.

Question 9

With regard to the process of neural transmission,a refractory period refers to a time interval in which

Accepted Answer

During the refractory period, the neuron is temporarily incapable of generating another action potential, regardless of the strength of the incoming signal. This is due to the fact that the neuron needs time to reset its ion channels after firing an action potential.

Question 10

Increasing excitatory signals above the threshold for neural activation will not affect the intensity of an action potential.This indicates that a neuron's reaction is

Accepted Answer

The statement "Increasing excitatory signals above the threshold for neural activation will not affect the intensity of an action potential" is a characteristic of the all-or-none response of neurons. This means that either a neuron will fire an action potential in response to a stimulus that reaches the threshold, or it will not fire an action potential at all. The intensity of the action potential is not affected by the strength of the stimulus, only whether or not the threshold has been met. The other answer choices (inhibited by the myelin sheath, delayed by a refractory period, and dependent on neurotransmitter molecules) do not accurately describe this phenomenon.

Question 11

Reuptake refers to the

Accepted Answer

Reuptake refers to the process of excess neurotransmitter molecules being reabsorbed by the sending neuron, in order to regulate the amount of neurotransmitters in the synapse. This allows for better communication between neurons by preventing an overstimulation or inhibition of the receiving neuron.

Question 12

A slap on the back is more painful than a pat on the back because a slap triggers

Accepted Answer

The answer of A slap on the back is more...

Question 13

Sir Charles Sherrington observed that impulses took an unexpectedly long time to travel a neural pathway.His observation provided evidence for the existence of

Accepted Answer

The answer of Sir Charles Sherrington observed that impulses took...

Question 14

Mr.Anderson suffers from Parkinson's disease and his shaking arm movements are so severe that he has difficulty feeding or dressing himself without help.His symptoms are most likely to be linked with an undersupply of the neurotransmitter

Accepted Answer

Parkinson's disease is a neurodegenerative disorder that affects the dopamine-producing neurons in the brain. The loss of dopamine results in motor symptoms such as tremors, rigidity, and difficulty initiating movements.

Question 15

Jacob's severe migraine headaches have led him to seek medical help.It is likely that his symptoms are most closely linked to an

Accepted Answer

The answer of Jacob's severe migraine headaches have led him...

Question 16

Schizophrenia is most closely linked to an oversupply of the neurotransmitter

Accepted Answer

Research has shown that an excess of dopamine in certain areas of the brain is associated with the symptoms of schizophrenia, including hallucinations and delusions. Antipsychotic medications work by blocking dopamine receptors in the brain, which helps to reduce the symptoms of schizophrenia.

Question 17

Neurotransmitters are released from knob-like terminals at the end of the

Accepted Answer

Neurotransmitters are released from the terminal buttons at the end of the axon into the synaptic cleft to communicate with other neurons or target cells.

Question 18

The chemical messengers released into the spatial junctions between neurons are called

Accepted Answer

Chemical messengers released into the spatial junctions between neurons are called neurotransmitters.

Question 19

Endorphins are

Accepted Answer

Endorphins are a type of neurotransmitter, which are chemical messengers in the brain that help to regulate mood, pain, and other bodily functions.

Question 20

Acetylcholine is a neurotransmitter that

Accepted Answer

Acetylcholine triggers muscle contractions.

Quiz 2: The Biology of Behavior