Question 1

Sympathetic ganglia:

Accepted Answer

Sympathetic ganglia are closely linked and often act as a single system. They are connected to form sympathetic chains along either side of the spinal cord. The fibers from these chains extend to different organs in the body, allowing for rapid and coordinated responses to stress or physical activity. Contrary to what is stated in option D, sympathetic ganglia have relatively long postganglionic fibers compared to parasympathetic ganglia. Option A is incorrect as sympathetic ganglia are located outside the spinal cord. Option B may be true to some extent, but it is not the best choice.

Question 2

The autonomic nervous system:

Accepted Answer

The autonomic nervous system receives and sends information to the heart, intestines, and other organs. It controls involuntary functions such as heart rate, digestion, and breathing. It is a part of the peripheral nervous system and operates without conscious control.

Question 3

Which part of the nervous system prepares the body for "fight or flight" activities?

Accepted Answer

The sympathetic nervous system is responsible for activating the body's response to stress, danger, or threat. It increases heart rate, constricts blood vessels, dilates pupils, and slows down digestion, all of which prepare the body for "fight or flight" activities.

Question 4

Axons of motor neurons would most likely be found in which of the following?

Accepted Answer

Motor neurons transmit signals from the central nervous system to muscles and glands, so their axons would most likely be found in white matter, which is composed largely of myelinated axons. Gray matter contains cell bodies and unmyelinated axons. Dorsal roots and tracts are primarily involved in sensory processing.

Question 5

Cell bodies of motor neurons would most likely be found in which of the following?

Accepted Answer

Gray matter, particularly in the anterior horns of the spinal cord and the motor cortex of the brain, contains the cell bodies of motor neurons. White matter contains the axons of neurons, while dorsal roots and tracts contain sensory neurons and their axons.

Question 6

Digestive activity is increased by the activation of which branch of the autonomic nervous system?

Accepted Answer

The parasympathetic branch of the autonomic nervous system is responsible for rest and digest functions, including increasing digestive activity.

Question 7

Seeing a snake come out of the drain in the bathtub might increase your heart rate, dilate your pupils, cause you to sweat, and raise the hair on your neck. These responses are due to the activity of the _____ nervous system.

Accepted Answer

The sympathetic nervous system is responsible for the fight or flight response, which includes increased heart rate, dilation of pupils, sweating, and goosebumps. This response is triggered by perceived danger or stress, such as the sight of a snake coming out of a bathtub drain. The parasympathetic nervous system, on the other hand, is responsible for the rest and digest response, which is the opposite of the fight or flight response. The somatic nervous system controls voluntary movements, and the motor nervous system controls the movement of muscles.

Question 8

In the spinal cord, white matter is comprised mostly of _____, while gray matter is mostly _____.

Accepted Answer

White matter in the spinal cord is composed mostly of myelinated axons, which are responsible for transmitting information up and down the spinal cord. Gray matter, on the other hand, contains mostly cell bodies and unmyelinated axons, which are responsible for processing information within the spinal cord itself.

Question 9

A cross section of the spinal cord indicates that gray matter is:

Accepted Answer

Gray matter in the spinal cord is densely packed with cell bodies and dendrites of neurons, and is responsible for processing and integrating information.

Question 10

You are walking after dark. A sudden noise frightens you. Your heart pounds, your pulse races, and your breathing rate increases. These responses are due to your:

Accepted Answer

The sudden noise causes the body's sympathetic nervous system to activate the "fight or flight" response which leads to an increase in heart rate, pulse rate, and breathing rate. The parasympathetic nervous system is responsible for the body's "rest and digest" response and is not involved in this scenario. The somatic nervous system controls voluntary muscle movement and is also not involved. The immune system fights off infections and is not relevant to this situation.

Question 11

Gray matter in the brain and spinal cord is mainly composed of what structures?

Accepted Answer

Gray matter in the brain and spinal cord contains cell bodies and dendrites of neurons.

Question 12

What is unique about the autonomic activity of the sweat glands?

Accepted Answer

Sweat glands are unique in that they receive only sympathetic input, which is responsible for stimulating sweat production.

Question 13

Sympathetic is to ____ as parasympathetic is to ____.

Accepted Answer

Sympathetic and parasympathetic are the two branches of the autonomic nervous system which are responsible for controlling various involuntary physiological functions in the body. Sympathetic activation prepares the body for action, while parasympathetic activation allows the body to rest and digest. Therefore, sympathetic is associated with arousal while parasympathetic is associated with relaxation.

Question 14

What, generally, is the relationship between the activity of the sympathetic and the parasympathetic nervous systems?

Accepted Answer

The sympathetic and parasympathetic nervous systems typically have opposite effects on the same organ. The sympathetic prepares the body for "fight or flight" responses, while the parasympathetic is responsible for "rest and digest" responses. Therefore, their activities are coordinated to maintain balance in the body's physiological processes.

Question 15

The sweat glands, adrenal glands, and muscles that constrict blood vessels have input from only the ____ nervous system.

Accepted Answer

The sympathetic nervous system is responsible for activating the sweat glands, adrenal glands, and muscles that constrict blood vessels in response to stress or danger. The parasympathetic nervous system, on the other hand, is responsible for regulating rest and digestion. The central nervous system is comprised of the brain and spinal cord, and the dorsal root is a sensory root that carries information from the peripheral nervous system to the spinal cord. The only appropriate answer is A, as it best fits the description of the physiological processes mentioned in the question.

Question 16

Where would you find the dorsal root ganglia?

Accepted Answer

The dorsal root ganglia are located outside, but near, the spinal cord. They are clusters of nerve cell bodies that are part of the peripheral nervous system and contain the cell bodies of sensory neurons. They are located just outside each vertebrae of the spinal column.

Question 17

Which activity is increased by the sympathetic nervous system?

Accepted Answer

The sympathetic nervous system is known for its fight or flight response, which increases heart rate to prepare the body for physical activity.

Question 18

If the spinal cord is cut at a given segment, the brain loses sensation at:

Accepted Answer

When the spinal cord is cut at a given segment, the brain loses sensation at that segment and all segments below it. This is because the spinal cord is responsible for transmitting sensory information from the body to the brain, and if it is cut, the information cannot be transmitted to the brain. However, information from segments above the cut can still be transmitted to the brain, which is why those segments are not affected.

Question 19

Which of the following would be the most likely effect of taking a drug that blocks sympathetic nervous system activity?

Accepted Answer

The sympathetic nervous system is responsible for increasing heart rate, so blocking its activity would lead to a decreased heart rate. Choice A is incorrect because the sympathetic nervous system also increases blood pressure, so blocking its activity would lead to a decrease in blood pressure. Choice B is incorrect because sweating is mainly controlled by the sympathetic nervous system, so blocking its activity would lead to decreased or no sweating. Choice C is incorrect because the sympathetic nervous system slows down digestion, so blocking its activity would actually increase digestion.

Question 20

Erection of the hairs, known in humans as "goose bumps," is caused by activation of which branch of the nervous system?

Accepted Answer

Erection of the hairs is caused by activation of the sympathetic nervous system, which triggers the muscle fibers around hair follicles to contract and lift the hair upright, causing "goose bumps".

Quiz 4: Anatomy of the Nervous System