Quizlet HESI A2 Anatomy and Physiology

Correct Answer: C

Rationale: The correct answer is C: Vitamin D. Vitamin D is essential for calcium absorption in the intestines by promoting the production of proteins that transport calcium. Without sufficient Vitamin D, the body cannot effectively absorb calcium, leading to potential bone and muscle weakness. Choice A: Vitamin A is not directly involved in calcium absorption. Choice B: Vitamin C is important for collagen synthesis and immune function but does not play a significant role in calcium absorption. Choice D: Vitamin K is primarily involved in blood clotting and bone health but does not directly affect calcium absorption.

Correct Answer: A

Rationale: Certainly! The correct answer is A: Pineal gland. The pineal gland is responsible for producing melatonin, a hormone that regulates sleep-wake cycles. The other choices, B: Thyroid gland, C: Adrenal gland, and D: Pituitary gland, do not produce melatonin. The thyroid gland produces hormones that regulate metabolism, the adrenal gland produces hormones such as cortisol and adrenaline, and the pituitary gland produces various hormones that control other glands in the endocrine system. Therefore, the pineal gland is the correct answer as it is specifically associated with melatonin production.

Correct Answer: C

Rationale: The correct answer is C: Appendix. The appendix is a small organ located near the junction of the small and large intestines. It plays a role in the immune system by harboring beneficial gut bacteria and promoting immune function. The heart (A), bronchi (B), and esophagus (D) are not directly involved in the immune system. The heart is responsible for pumping blood, bronchi are part of the respiratory system, and the esophagus is involved in digestion.

Correct Answer: B

Rationale: The primary function of the respiratory system is to transport oxygen to the cells. Oxygen is crucial for cellular respiration, which produces energy for the body. The respiratory system accomplishes this through breathing, where oxygen is inhaled and transported via the bloodstream to cells. Removing carbon dioxide (choice A) is an important secondary function. Delivering nutrients (choice C) is the role of the circulatory system. Creating sound and speech (choice D) is the function of the larynx and vocal cords, not the entire respiratory system.

Correct Answer: B

Rationale: The primary function of the lymphatic system is to remove carbon dioxide from the body. Lymphatic vessels collect excess fluid and waste products from tissues and transport them back to the bloodstream for elimination. This process helps maintain fluid balance and removes metabolic waste. The other choices are incorrect because: A: Transporting oxygen to cells is primarily done by the circulatory system. C: Hormone production is mainly regulated by the endocrine system. D: Nutrient transport is primarily the role of the digestive system and the circulatory system.