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. Which of the following is a role of platelets in hemostasis?

A. formation of plugs
B. promotion of vasodilation
C. conversion of prothrombin to thrombin
D. activation of calcium

Correct answer: A

Rationale: Platelets play a crucial role in hemostasis by forming plugs to stop bleeding. Choice B is incorrect because platelets do not promote vasodilation; instead, they help in vasoconstriction. Choice C is incorrect as the conversion of prothrombin to thrombin is a function of the coagulation cascade involving various clotting factors, not platelets. Choice D is incorrect as platelets do not directly activate calcium; instead, they play a role in the activation of other clotting factors.

3. Macromolecules are built of?

A. Monomers
B. Incorrect
C. Not Applicable
D. None of the above

Correct answer: A

Rationale: The correct answer is A: Monomers. Macromolecules are built from smaller subunits called monomers. Monomers join together through chemical reactions to form larger molecules known as macromolecules. Option B is incorrect as it does not provide the accurate information regarding the composition of macromolecules. Option C is not applicable as it does not offer a relevant choice. Option D is incorrect because there is a specific answer related to the composition of macromolecules.

4. Signs of aging at the cellular level are

A. graying hair, waning strength, and wrinkles.
B. unrepaired DNA and abnormal proteins.
C. impaired cell division and the ability to break down and recycle worn cell parts.
D. a fatty liver and clogged blood vessels.

Correct answer: C

Rationale: The correct answer is 'impaired cell division and the ability to break down and recycle worn cell parts.' Aging at the cellular level involves reduced efficiency in cell division and the breakdown/recycling of cellular components, leading to functional decline. Choices A, B, and D are incorrect because they involve external physical manifestations or organ-specific issues rather than cellular-level changes associated with aging.

5. Which of the following organs is in the abdominopelvic cavity?

A. The heart
B. The trachea
C. The thymus
D. The liver

Correct answer: D

Rationale: The correct answer is the liver. The liver is located in the abdominopelvic cavity, which is the space between the diaphragm and the pelvic floor. The heart, trachea, and thymus are not located in the abdominopelvic cavity. The heart is situated in the thoracic cavity, the trachea is in the neck region, and the thymus is located in the upper chest. Understanding the anatomical locations of organs is crucial for medical professionals to accurately diagnose and treat patients.