HESI A2 Anatomy and Physiology Quizlet 2024

Correct Answer: A

Rationale: The correct answer is A (70 or higher) because high-density lipoprotein (HDL) cholesterol is considered "good" cholesterol that helps remove other forms of cholesterol from the bloodstream. HDL levels of 70 or higher are associated with a lower risk of heart disease. Regular testing of HDL levels is recommended to monitor cardiovascular health. Choice B (60) is not as optimal as 70 or higher. Choices C (50) and D (40) are even lower and would indicate a higher risk of heart disease. Regular testing is crucial to track changes in HDL levels for early intervention if needed.

Correct Answer: C

Rationale: The correct answer is C because the intercostal muscles assist with respiration by enlarging and reducing the space in the thorax during inhalation and exhalation. During inhalation, these muscles contract to lift the ribcage, expanding the thoracic cavity to allow the lungs to fill with air. During exhalation, they relax to decrease the thoracic cavity size, helping to expel air from the lungs. Choice A is incorrect because the intercostal muscles do not directly protect the delicate bronchioles and alveoli. Choice B is incorrect as these muscles do not signal a decrease in intra-alveolar pressure. Choice D is incorrect because the primary function of the intercostal muscles is not to maintain a medial separation between pleurae.

Correct Answer: D

Rationale: The correct answer is D: Cardiovascular system. Arteries are blood vessels that carry oxygen-rich blood away from the heart to the rest of the body. The cardiovascular system includes the heart, blood vessels, and blood. Arteries play a crucial role in this system by facilitating the circulation of blood. Explanation for incorrect choices: A: Nervous system - Arteries are not a part of the nervous system, which primarily consists of the brain, spinal cord, and nerves. B: Endocrine system - Arteries are not directly involved in the endocrine system, which is responsible for hormone production and regulation. C: Lymphatic system - Arteries are not part of the lymphatic system, which includes lymph nodes, lymphatic vessels, and lymph fluid.

Correct Answer: B

Rationale: Exocytosis is the process where the cell releases substances outside by fusing vesicles with the plasma membrane. This is the correct answer as it accurately describes the mechanism of exocytosis. The other choices are incorrect because: A. Describes endocytosis, not exocytosis. C. Describes pinocytosis, not exocytosis. D. Describes phagocytosis, not exocytosis. Therefore, the correct answer is B as it specifically relates to the process of exocytosis.

Correct Answer: A

Rationale: The correct answer is A: right atrium. The vena cavae are large veins that carry deoxygenated blood from the body back to the heart. They empty into the right atrium, which is the receiving chamber for deoxygenated blood. The blood then passes through the tricuspid valve into the right ventricle for pumping to the lungs for oxygenation. Choices B, C, and D are incorrect because the vena cavae do not empty into the ventricles; they empty into the atria. Therefore, the correct answer is A as it accurately reflects the anatomical pathway of blood flow from the vena cavae back to the heart.