What is the general purpose of positive feedback mechanisms?
A. to maintain a constant internal environment
B. to anticipate changes in the environment
C. to return a variable toward the set point
D. to bring about a rapid change in the body
E. to detect changes in the external environment
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Question 2) Which situation describes a feedforward mechanism?
A. Blood glucose returns toward normal an hour after a meal.
B. The smell of rotten food on a plate triggers the vomit reflex.
C. A drop in core body temperature triggers shivering.
D. An increase in core body temperature stimulates sweating.
E. Food in the stomach triggers the production of stomach acid.
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Question 3) Describing a physiological variable as homeostatic means that it
A. has varied from the normal value, and will remain constant at the new value.
B. never varies from an exact set point value.
C. is in an equilibrium state that requires no energy input to stay at the normal value.
D. is in a state of dynamic constancy that is regulated to remain near a stable set point value.
E. has no normal range, but will just change to match the outside environmental conditions.
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Question 4) Which of the following situations best represents a homeostatic mechanism?
A. A person who becomes very nervous begins to sweat profusely.
B. After going outside on a hot day, the core body temperature increases.
C. Increasing the size of fast-food restaurant portions causes body weight to increase.
D. After eating a large batch of salty popcorn, levels of salt in the urine increase.
E. As age increases, the amount of calcium in bones tends to decrease.
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Question 5) What term is used to describe the steady-state value for any variable that the body attempts to maintain?
A. Set point
B. Equilibrium potential
C. Error signal
D. Reflex arc
E. Median value
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Question 6) Feedforward regulatory processes
A. work in anticipation of changes in regulated variables.
B. are identical to positive feedback processes
C. lead to instability of the regulated variable
D. maximize fluctuations in the regulated variable
E. tend to force physiological variables away from their set point.
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Question 7) Which of components of a general reflex arc are listed in the order information typically flows through them following a stimulus?
A. effector, afferent pathway, integrating center, efferent pathway, receptor
B. effector, efferent pathway, integrating center, afferent pathway, receptor
C. integrating center, receptor, afferent pathway, efferent pathway, effector
D. receptor, efferent pathway, integrating center, afferent pathway, effector
E. receptor, afferent pathway, integrating center, efferent pathway, effector
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Question 8) What is the term for the developmental process that leads to specialized cell types?
A. genomics
B. differentiation
C. homeostasis
D. positive feedback
E. acclimatization
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Question 9) If a person begins to sweat upon entering a hot room but continued sweating is able to keep the body temperature constant, which of these best describes her condition?
A. She is in an equilibrium state.
B. She is not using energy to maintain a constant temperature.
C. She is in a steady state
D. She is using a positive feedback mechanism.
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Question 10) Which best describes the extracellular matrix?
A. It is found just inside the cell membrane in all tissues, it sends branching collagen fibers between cells to connect them, and it transmits chemical information from the interior of one cell to the interior of adjacent cells.
B. It is a tissue having more than the four general cell types, it transports proteins and polysaccharides between body compartments, and it is the route by which chemical signals like hormones reach all parts of the body.
C. It covers the body's surface, it contains connective and muscle tissue, and it helps generate movement.
D. It surrounds cells; it contains proteins, polysaccharides, and minerals; it provides a scaffold for cell attachment; and it transmits chemical messengers to cells.
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