Question 1

The rapid shift of the neuron's electrical potential from -70 millivolts to +40 millivolts is called:

Accepted Answer

The rapid shift of the neuron's electrical potential from -70 millivolts to +40 millivolts is called an action potential.

Question 2

The Branchlike fibers that collect messages from the adjacent neurons and pass them along to the cell body of the receiving neuron are called ________________.

Accepted Answer

Dendrites are the branchlike structures that collect messages from adjacent neurons and transmit them to the cell body of the receiving neuron. Axons are the long, thin fiber that carries electrical signals from the cell body to the terminal buttons, where neurotransmitters are released. Potentials refer to the difference in electrical charge between the inside and outside of a neuron. Neurotransmitters are chemicals that transmit signals between neurons.

Question 3

Neurons have three main parts,they are the:

Accepted Answer

Neurons have three main parts which are dendrites, axon, and soma. Soma (also known as the cell body) contains the nucleus and other organelles; dendrites receive signals from other neurons; and the axon carries signals away from the soma to other neurons or muscles. Myelin sheath is a covering around some axons but not one of the essential parts of the neuron itself.

Question 4

When the myelin coating is damaged,the:

Accepted Answer

When the myelin coating is damaged, the timing of nerve impulses to the muscles is interrupted. This is because myelin helps to speed up the transmission of nerve impulses along the axon. Without myelin, nerve impulses can slow down or even stop altogether, which can lead to muscle weakness or paralysis. Damage to myelin is associated with several neurological conditions, including multiple sclerosis.

Question 5

The division of the axon into many branches (several hundreds in some cases)with endings makes it possible for a single neuron to connect to the dendrites of as many as 50,000 other neurons.These endings are called:

Accepted Answer

The endings of the axon branches are called axon terminals. Option A, cell bodies, are the nucleus-containing part of the neuron, while option B, dendrites, are the branched extensions of the neuron that receive signals from other neurons. Option D, glial cells, are support cells of the nervous system. Therefore, the best choice is C, axon terminals.

Question 6

Axon is to dendrite as:

Accepted Answer

Axon is responsible for sending signals, while dendrites are responsible for receiving signals. Therefore, the relationship between axon and dendrite is analogous to the relationship between send and receive.

Question 7

One of the functions of _____________ is to surround neurons and hold them in place.

Accepted Answer

Glial cells, also known as neuroglia, serve a supportive role in the nervous system, and one of their functions is to provide structural support for neurons. They surround and hold neurons in place, provide metabolic support, and play a role in communication between neurons. Axons (A) are the part of the neuron that sends signals, while axon terminals (B) are the structures at the end of the axon that release neurotransmitters. Cell bodies (D) contain the nucleus and most of the organelles of the neuron.

Question 8

The dendrite's function is to:

Accepted Answer

The dendrite's function is to receive incoming chemical messages from neighboring neurons and send them on to the cell body.

Question 9

Which of the following represents the normal order of activation in neuronal transmission?

Accepted Answer

The normal order of activation in neuronal transmission is dendrite → soma → axon → axon terminal. This means that the activation starts in the dendrites, moves through the soma (cell body), down the axon, and ends at the axon terminals where the neurotransmitters are released to communicate with the next neuron or target cell.

Question 10

The overall charge inside a resting neuron is:

Accepted Answer

The resting neuron has a negative charge on the inside (around -70 mV) compared to the outside, which is positive. This resting potential is maintained by the balance of positively charged ions outside the cell and negatively charged ions inside the cell.

Question 11

The nucleus of the neuron and the biochemical structures needed for cell survival are contained in the:

Accepted Answer

The cell body, also known as the soma, contains the nucleus and other necessary structures for the survival of the neuron. The axon is responsible for transmitting signals, the dendrites receive signals, and the myelin sheath is a protective coating around the axon.

Question 12

When a neuron is stimulated,tiny protein structures embedded in the cell membrane are activated and allow specific ions to cross the cell membrane,thus changing the overall potential of the neuron.These tiny protein structures are called _____________.

Accepted Answer

Ion channels are the protein structures embedded in the cell membrane that allow specific ions to cross the cell membrane, resulting in a change in the overall potential of the neuron. Action potentials refer to the electrical signals that travel along the neuron, while neurotransmitters are chemicals that are released by neurons to communicate with other neurons or cells. Glial cells are support cells in the nervous system and do not play a direct role in neuron stimulation.

Question 13

Shortly after a neural impulse has been triggered,for a brief period of time,the neuron is not excitable and cannot fire another impulse.This is called _____________.

Accepted Answer

During the absolute refractory period, the neuron is unable to fire another impulse, even if a strong stimulus is presented. This is due to the fact that the neuron is in the midst of repolarizing after an action potential, and cannot be stimulated again until it reaches its resting potential.

Question 14

The basic building blocks of the nervous system are specialized cells called:

Accepted Answer

Neurons are specialized cells that make up the basic building blocks of the nervous system. Nerves are bundles of neurons and dendrites are extensions of neurons that receive incoming information. Hormones are chemical messengers produced by glands and are part of the endocrine system, which works in tandem with the nervous system.

Question 15

Which of the following statements is TRUE?

Accepted Answer

Glial cells are more numerous than neurons in the human brain, with estimates suggesting they outnumber neurons by about 10 to 1, providing structural support, protection, and nutrition to neurons.

Question 16

Which of the following is NOT a function of glial cells?

Accepted Answer

Glial cells do not send and receive nerve impulses. This is the primary function of neurons.

Question 17

The all-or-none law of neural conduction suggests that:

Accepted Answer

The all-or-none law of neural conduction suggests that once the action potential threshold is met, an action potential of uniform and maximum intensity occurs. This means that the strength of the action potential doesn't vary depending on the strength of the stimulus, but rather either it will happen fully or not happen at all.

Question 18

Small variable changes in the electrical potential of a neuron that occur in the dendrites and cell body are called:

Accepted Answer

Small variable changes in the electrical potential of a neuron that occur in the dendrites and cell body are called graded potentials. Resting potentials refer to the steady state electrical charge of a neuron when it is not transmitting signals, while action potentials are rapid and brief changes in the membrane potential of a neuron that result in the transmission of a nerve impulse. Polarized potentials is not a recognized term in neuroscience.

Question 19

A neuron's action potential is also known as a(n):

Accepted Answer

A neuron's action potential is also known as a nerve impulse, which is the electrical signal that travels down the axon of the neuron. Graded potentials refer to local changes in membrane potential that do not reach threshold and do not initiate an action potential. Ion potential is not a commonly used term in neuroscience. Refractory period refers to the period of time in which an excitable cell cannot generate another action potential in response to a normal threshold stimulus.

Question 20

The threshold that must be reached to trigger an action potential in most neurons is:

Accepted Answer

The threshold that must be reached to trigger an action potential in most neurons is around -50 millivolts. Once the membrane potential reaches this threshold, voltage-gated ion channels open and allow for the rapid influx of sodium ions, leading to depolarization and the generation of an action potential.

Quiz 3: Biological Foundations of Behaviour