which of the following cardiac valves prevents blood from returning to the left ventricle of the heart

ATI RN

ATI Anatomy and Physiology

1. Which of the following cardiac valves prevents blood from returning to the left ventricle of the heart?

A. pulmonic
B. mitral
C. tricuspid
D. aortic

Correct answer: D

Rationale: The correct answer is the aortic valve. The aortic valve is located between the left ventricle and the aorta, preventing the backflow of blood into the left ventricle once it has been pumped out during systole. Choice A, pulmonic, is incorrect as it is associated with the right side of the heart. Choice B, mitral, is incorrect as it is the valve between the left atrium and ventricle. Choice C, tricuspid, is incorrect as it is located between the right atrium and ventricle.

2. 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.

3. Which of the following is not true of organelles?

A. They carry out specific activities.
B. They are only present in human cells.
C. They are composed of aggregates of large molecules.
D. They are found in many types of cells.

Correct answer: B

Rationale: Organelles are not exclusive to human cells but are present in various types of cells across different organisms. Option B is incorrect as it suggests that organelles are only found in human cells, which is false. Choices A, C, and D are correct statements about organelles. Organelles indeed carry out specific activities, are made up of aggregates of large molecules, and can be found in many types of cells.

4. What effect does aldosterone secretion have on electrolyte levels?

A. Calcium levels are decreased
B. Sodium levels are increased
C. Potassium levels are increased
D. Magnesium levels are decreased

Correct answer: B

Rationale: Aldosterone is a hormone that primarily acts on the kidneys to increase the reabsorption of sodium and water into the bloodstream. As a result, sodium levels are increased. Choices A, C, and D are incorrect. Aldosterone does not significantly affect calcium, potassium, or magnesium levels.

5. Which of the following lists best illustrates the idea of increasing levels of complexity?

A. Cells, tissues, organelles, organs, organ systems
B. Tissues, cells, organs, organelles, organ systems
C. Organs, organelles, organ systems, cells, tissues
D. Organelles, cells, tissues, organs, organ systems

Correct answer: D

Rationale: The correct answer is D: Organelles, cells, tissues, organs, organ systems. This list correctly depicts the increasing levels of complexity in biological organization. It starts with organelles, which are subunits within cells, followed by cells, then tissues (groups of cells working together), organs (comprised of different tissues), and finally organ systems (multiple organs working together). Choices A, B, and C are incorrect as they do not follow the logical progression of complexity from smaller units to larger, more complex structures.