Deck 3: Control of the Internal Environment

Question 1

Most control systems of the body operate via

A) positive feedback.
B) low-gain receptors.
C) negative feedback.
D) feed forward mechanisms.

Answer 1

C

Question 2

The precision with which a control system maintains homeostasis is termed

A) positive feedback.
B) negative feedback.
C) set point.
D) gain.

Answer 2

D

Question 3

The gain of a biological control system can be thought of as the

A) amount of amplification of the system or the precision with which the control system maintains homeostasis.
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).
C) positive feedback needed to maintain homeostasis.
D) stimulus that triggers the biological control system to bring the internal environment back to normal.

Answer 3

A

Question 4

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

Question 5

Translation is the production of a protein from mRNA at the

A) nucleus.
B) ribosome.
C) mitochondria.
D) Golgi apparatus.

Question 6

Which of the following is an example of positive feedback?

A) regulation of blood glucose
B) regulation of body temperature
C) labor contractions during childbirth
D) the cellular stress protein response

Question 7

A series of interconnected components that serve to maintain a physical or chemical parameter of the body near a constant value is

A) homeostasis.
B) steady state.
C) a biological control system.
D) an organ system.

Question 8

The term homeostasis is defined as

A) a constant metabolic demand placed upon the body.
B) the maintenance of a constant internal environment.
C) a low metabolic rate.
D) a change within the internal environment.

Question 9

The effectors in the response to increased body temperature include

A) cutaneous blood vessels and sweat glands.
B) cutaneous blood vessels and skeletal muscle.
C) baroreceptors.
D) stretch receptors.

Question 10

In negative feedback, the response of the system is

A) to increase the gain of the receptor.
B) to modify the receptor's response to the stimulus.
C) opposite to that of the stimulus.
D) to enhance the stimulus.

Question 11

In protein synthesis, the formation of mRNA is called

A) transcription.
B) translation.

Question 12

A chemical messenger is released from one cell that stimulates nearby cells is an example of

A) autocrine signaling.
B) endocrine signaling.
C) juxtacrine signaling.
D) paracrine signaling.

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

A) homeostasis.
B) effector.
C) steady state.
D) changing internal environment.

Question 14

Physiologists use the term steady state to denote

A) a steady and unchanging level of a physiological variable.
B) a completely normal external environment.
C) a changing internal environment.
D) an increase in body heat storage.

Question 15

Endocrine signaling involves the release of _________ into the bloodstream.

A) heat shock proteins
B) neurotransmitters
C) hormones
D) transcription factors

Question 16

Which of the following would occur in response to elevated blood glucose to maintain homeostasis?

A) decreased insulin secretion from the pancreas
B) increased uptake of glucose by cells
C) continued elevation of blood glucose
D) all of the above

Question 17

Stress proteins that are manufactured by cells in response to exercise

A) can lead to an increased production of free radicals.
B) can lead to further disruptions in homeostasis.
C) can lead to an increased degree of cellular injury.
D) can help to repair damage caused by free radicals.

Question 18

The general components of a biological control system are the

A) receptor, control center, and response.
B) receptor, control center, and effector.
C) effector, remote control, and stimulus.
D) receptor and integrating center.