the recent discovery of taste receptors that detect sweetness in the small intestine illustrates that

ATI RN

ATI Anatomy and Physiology Online Practice

1. The recent discovery of taste receptors that detect sweetness in the small intestine illustrates that

A. chemical responses occur in various parts of the body.
B. new discoveries about anatomy and physiology are still being made.
C. everything about anatomy and physiology has been discovered.
D. the molecular and cellular level is crucial in anatomy and physiology.

Correct answer: B

Rationale: The recent discovery of taste receptors in the small intestine illustrates that new discoveries about anatomy and physiology are still being made. This finding demonstrates that our understanding of the human body is continuously evolving. Choice A is incorrect because the discovery does not imply that chemical responses occur in only one part of the body but rather showcases a specific new discovery. Choice C is incorrect as it is highly improbable that everything about anatomy and physiology has been discovered given the complexity of the human body. Choice D is incorrect as while the molecular and cellular level is important in anatomy and physiology, the primary focus of this discovery is on the new findings about the taste receptors in the small intestine.

2. Living organisms use oxygen to __________________.

A. reduce heat production
B. accept electrons for cellular metabolism
C. release energy stored in the molecules of food
D. remove metabolic wastes

Correct answer: C

Rationale: The correct answer is C. Living organisms use oxygen to release energy stored in the molecules of food through a process called cellular respiration. This process involves breaking down glucose molecules in the presence of oxygen to produce energy in the form of ATP. Choice A is incorrect because oxygen does not directly reduce heat production in organisms. Choice B is incorrect because oxygen is involved in accepting electrons rather than donating them in cellular metabolism. Choice D is incorrect because the removal of metabolic wastes is not the primary role of oxygen in living organisms.

3. Which of the following is not an example of a homeostatic mechanism in the human body?

A. Shivering when the body temperature falls below normal.
B. Increasing heart rate and force of contraction when blood pressure falls.
C. Retaining fluid excessively.
D. Secreting insulin after a meal to return blood sugar concentration toward normal.

Correct answer: C

Rationale: The correct answer is C. Homeostatic mechanisms aim to maintain internal stability within the body. Choices A, B, and D all represent examples of homeostatic mechanisms. Shivering helps generate heat to raise body temperature back to normal levels. Increasing heart rate and force of contraction work to restore blood pressure. Insulin secretion after a meal helps regulate blood sugar levels. On the other hand, retaining fluid excessively can lead to fluid imbalance rather than maintaining internal stability, making it the incorrect choice.

4. Which of the following illustrates a positive feedback mechanism?

A. Maintaining blood pressure
B. Uterine contractions during childbirth
C. Body temperature control
D. Control of blood sugar

Correct answer: B

Rationale: The correct answer is uterine contractions during childbirth. This is an example of a positive feedback mechanism where the initial stimulus (contractions) leads to an increase in intensity and frequency, ultimately resulting in childbirth. In contrast, choices A, C, and D (maintaining blood pressure, body temperature control, and control of blood sugar) are examples of negative feedback mechanisms. These mechanisms work to maintain stability by counteracting any deviations from the set point, rather than amplifying the response like in a positive feedback mechanism.

5. Metabolism is defined as _____.

A. the removal of wastes produced by chemical reactions
B. the breakdown of substances into simpler forms
C. the taking in of nutrients
D. all the chemical reactions occurring in an organism that support life

Correct answer: D

Rationale: Metabolism refers to all the chemical reactions that take place within an organism to sustain life, including processes such as breaking down molecules, building new molecules, and energy production. Choice A is incorrect because it describes excretion rather than metabolism. Choice B is incorrect as it specifically refers to the breakdown of substances, not encompassing the entirety of metabolic processes. Choice C is incorrect as it focuses solely on nutrient intake, which is just one aspect of metabolism.