Question 1

Most control systems of the body operate via&#10;A) positive feedback.&#10;B) low-gain receptors.&#10;C) negative feedback.&#10;D) feed forward mechanisms.

Accepted Answer

Negative feedback is a common type of control system in the body where the response or output of a process is directed to counteract the stimulus or input. This helps maintain homeostasis and stability in the body's internal environment. Positive feedback is less common in the body as it amplifies the initial signal or response, leading to exponential growth or change, which can be harmful. Low-gain receptors refer to the sensitivity of a receptor, and feed forward mechanisms are processes that anticipate changes and adjust outputs accordingly.

Question 2

The precision with which a control system maintains homeostasis is termed&#10;A) positive feedback.&#10;B) negative feedback.&#10;C) set point.&#10;D) gain.

Accepted Answer

The precision with which a control system maintains homeostasis is defined by gain, which is the ratio of output response to input stimulus. Choices A, B, and C are all important aspects of control systems, but they do not define the precision of the system's maintenance of homeostasis.

Question 3

The gain of a biological control system can be thought of as the&#10;A) amount of amplification of the system or the precision with which the control system maintains homeostasis.&#10;B) ratio of the amount of abnormality to the amount of correction needed to maintain a constant internal environment (i.e., amount abnormality/amount of correction needed).&#10;C) positive feedback needed to maintain homeostasis.&#10;D) stimulus that triggers the biological control system to bring the internal environment back to normal.

Accepted Answer

The gain of a biological control system refers to how much the system amplifies or increases the response to a stimulus. It can also refer to how precise the system is in maintaining homeostasis, both of which are accurately described in option A. Option B is not correct as it describes a ratio of abnormality to correction, which is not directly related to the gain of the system. Option C is incorrect as positive feedback is generally not conducive to maintaining homeostasis. Option D is incorrect as it only describes the trigger for the system, not the gain.

Question 4

Because of complex control systems, the body always maintains homeostasis, even during exercise.

Accepted Answer

During exercise, the body experiences temporary changes in homeostasis, such as increased heart rate and body temperature, to meet the demands of physical activity.

Question 5

Translation is the production of a protein from mRNA at the&#10;A) nucleus.&#10;B) ribosome.&#10;C) mitochondria.&#10;D) Golgi apparatus.

Accepted Answer

Translation occurs at the ribosome, where the mRNA sequence is read and used to assemble a specific amino acid sequence, forming a protein. The nucleus is where mRNA is transcribed from DNA, but it is not where translation occurs. The mitochondria and Golgi apparatus have other roles in the cell and are not involved in protein synthesis.

Question 6

Which of the following is an example of positive feedback?&#10;A) regulation of blood glucose&#10;B) regulation of body temperature&#10;C) labor contractions during childbirth&#10;D) the cellular stress protein response

Accepted Answer

Positive feedback is a process in which an initial stimulus leads to an increase in the response that intensifies the stimulus. Labor contractions during childbirth is a classic example of positive feedback as the stretching of the cervix during contractions stimulates the release of the hormone oxytocin, which in turn causes more intense contractions, leading to further cervical stretching, and so on until delivery. The other options listed are examples of negative feedback, in which the response to a stimulus counteracts or opposes the original stimulus to maintain homeostasis.

Question 7

A series of interconnected components that serve to maintain a physical or chemical parameter of the body near a constant value is&#10;A) homeostasis.&#10;B) steady state.&#10;C) a biological control system.&#10;D) an organ system.

Accepted Answer

A series of interconnected components that serve to maintain a physical or chemical parameter of the body near a constant value is called a biological control system. Homeostasis refers to the overall concept of the body maintaining stable internal conditions. Steady state refers specifically to a system where inputs and outputs are balanced, but not necessarily at a constant level. Organ system refers to a group of organs working together to perform a specific function.

Question 8

The term homeostasis is defined as&#10;A) a constant metabolic demand placed upon the body.&#10;B) the maintenance of a constant internal environment.&#10;C) a low metabolic rate.&#10;D) a change within the internal environment.

Accepted Answer

Homeostasis refers to the ability of an organism to maintain a stable internal environment, even when faced with external changes. This includes maintaining constant levels of temperature, pH, and concentrations of various substances within the body. Choice A is incorrect because homeostasis involves maintaining balance rather than placing a demand. Choice C is incorrect because the metabolic rate can vary in different situations. Choice D is incorrect because homeostasis actually involves preventing or minimizing changes within the internal environment.

Question 9

The effectors in the response to increased body temperature include&#10;A) cutaneous blood vessels and sweat glands.&#10;B) cutaneous blood vessels and skeletal muscle.&#10;C) baroreceptors.&#10;D) stretch receptors.

Accepted Answer

Cutaneous blood vessels and sweat glands are responsible for decreasing body temperature during a heat response. Cutaneous blood vessels dilate to increase blood flow to the skin, allowing heat to be dissipated, while sweat glands produce sweat that helps cool the skin through the process of evaporation. Baroreceptors and stretch receptors are not involved in the response to increased body temperature.

Question 10

In negative feedback, the response of the system is&#10;A) to increase the gain of the receptor.&#10;B) to modify the receptor's response to the stimulus.&#10;C) opposite to that of the stimulus.&#10;D) to enhance the stimulus.

Accepted Answer

In negative feedback, the response of the system is to oppose or reverse the stimulus, leading to a stabilization or return to a set point. This is achieved through processes like inhibiting further stimulus detection or reducing the output response. As a result, the response of the system is opposite to that of the stimulus. Options A, B, and D do not describe the typical response of a negative feedback system.

Question 11

In protein synthesis, the formation of mRNA is called&#10;A) transcription.&#10;B) translation.

Accepted Answer

The answer of In protein synthesis, the formation of mRNA...

Question 12

A chemical messenger is released from one cell that stimulates nearby cells is an example of&#10;A) autocrine signaling.&#10;B) endocrine signaling.&#10;C) juxtacrine signaling.&#10;D) paracrine signaling.

Accepted Answer

The answer of A chemical messenger is released from one...

Question 13

During 60 minutes of constant-load submaximal exercise, the body temperature reaches a plateau after 35-45 minutes. This is an example of&#10;A) homeostasis.&#10;B) effector.&#10;C) steady state.&#10;D) changing internal environment.

Accepted Answer

The answer of During 60 minutes of constant-load submaximal exercise,...

Question 14

Physiologists use the term steady state to denote&#10;A) a steady and unchanging level of a physiological variable.&#10;B) a completely normal external environment.&#10;C) a changing internal environment.&#10;D) an increase in body heat storage.

Accepted Answer

The answer of Physiologists use the term steady state to...

Question 15

Endocrine signaling involves the release of _________ into the bloodstream.&#10;A) heat shock proteins&#10;B) neurotransmitters&#10;C) hormones&#10;D) transcription factors

Accepted Answer

The answer of Endocrine signaling involves the release of _________...

Question 16

Which of the following would occur in response to elevated blood glucose to maintain homeostasis?&#10;A) decreased insulin secretion from the pancreas&#10;B) increased uptake of glucose by cells&#10;C) continued elevation of blood glucose&#10;D) all of the above

Accepted Answer

The answer of Which of the following would occur in...

Question 17

Stress proteins that are manufactured by cells in response to exercise&#10;A) can lead to an increased production of free radicals.&#10;B) can lead to further disruptions in homeostasis.&#10;C) can lead to an increased degree of cellular injury.&#10;D) can help to repair damage caused by free radicals.

Accepted Answer

The answer of Stress proteins that are manufactured by cells...

Question 18

The general components of a biological control system are the&#10;A) receptor, control center, and response.&#10;B) receptor, control center, and effector.&#10;C) effector, remote control, and stimulus.&#10;D) receptor and integrating center.

Accepted Answer

The answer of The general components of a biological control...

Deck 3: Control of the Internal Environment