homeostasis is the

ATI RN

ATI Anatomy and Physiology Online Practice

1. What is homeostasis?

A. The inability to keep body weight within normal limits.
B. Room temperature decreasing because a window is open.
C. Ingestion of more food than needed.
D. The tendency of the body to maintain a stable internal environment.

Correct answer: D

Rationale: The correct answer is D: Homeostasis refers to the body's ability to maintain a stable internal environment despite external changes. Choices A, B, and C are incorrect. Choice A describes obesity, choice B describes a specific scenario with room temperature, and choice C refers to overeating, which is not related to homeostasis.

2. Homeostasis exists if concentrations of water, nutrients, and oxygen in the body and heat and pressure __________.

A. decrease steadily
B. remain within certain limited ranges
C. increase when the body is stressed
D. fluctuate greatly between very high and low values

Correct answer: B

Rationale: Homeostasis is the body's ability to maintain stable internal conditions despite external changes. To achieve this balance, concentrations of essential substances must remain within specific ranges. Choice A is incorrect because decreasing concentrations would not maintain stability. Choice C is incorrect as increasing concentrations when the body is stressed would disrupt homeostasis. Choice D is incorrect as fluctuating greatly between high and low values would also not support the body's stability. Therefore, the correct answer is B, as it aligns with the concept of homeostasis by emphasizing the need for stability within certain limits.

3. Which of the following describes the event of ovulation?

A. The fallopian tube moves the ovum to the uterus.
B. The oocyte undergoes its first meiotic division.
C. The Graafian follicle releases an ovum.
D. The corpus luteum produces progesterone.

Correct answer: C

Rationale: Ovulation is the release of a mature egg (ovum) from the Graafian follicle in the ovary. This process is essential for fertilization. Choice A is incorrect because the fallopian tube does not move the ovum to the uterus; rather, it provides a pathway for the egg to travel from the ovary to the uterus. Choice B is incorrect as the oocyte undergoes its first meiotic division after ovulation. Choice D is incorrect because the corpus luteum forms after ovulation and is responsible for producing progesterone.

4. Which of the following processes does not help maintain the life of an individual organism?

A. Responsiveness
B. Movement
C. Reproduction
D. Respiration

Correct answer: C

Rationale: Reproduction is the correct answer because it is not essential for maintaining the life of an individual organism. While reproduction is crucial for the continuation of a species, it is not directly related to the survival or maintenance of an individual organism. Responsiveness allows an organism to react to stimuli, movement helps in obtaining resources and avoiding danger, and respiration provides the necessary energy for life processes. Therefore, reproduction is the process that does not directly contribute to maintaining the life of an individual organism.

5. Peripheral vasodilation results in heat loss through which of the following processes?

A. conduction
B. convection
C. radiation
D. evaporation

Correct answer: C

Rationale: Peripheral vasodilation is the widening of blood vessels near the surface of the skin, allowing more blood to flow near the skin's surface. This process enhances heat loss primarily through radiation. Radiation is the transfer of heat energy in the form of electromagnetic waves. Conduction involves direct contact between objects, convection involves the transfer of heat through fluid or gas, and evaporation involves the phase change of a liquid to a gas, which cools the surface.