Quizlet HESI A2 Anatomy and Physiology

Correct Answer: B

Rationale: Platelets play a crucial role in blood clotting. When a blood vessel is damaged, platelets adhere to the site to form a plug to stop bleeding. This process is essential for wound healing and preventing excessive blood loss. Platelets do not transport oxygen (A), fight infection (C), or transport nutrients (D). Oxygen is carried by red blood cells, immune cells fight infection, and nutrients are transported by plasma and other blood components.

Correct Answer: B

Rationale: The correct answer is B: Heart. The heart is not a component of the central nervous system (CNS) as it is part of the cardiovascular system. The CNS consists of the brain, spinal cord, and retina. The brain controls cognitive functions, the spinal cord transmits nerve signals, and the retina is a part of the visual system. Choice B is incorrect as the heart's function is to pump blood and is not involved in CNS functions.

Correct Answer: A

Rationale: The correct answer is A: Pharynx. The pharynx is a structure in the upper respiratory tract that connects the nasal cavity and mouth to the larynx and esophagus. It serves as a passageway for both air and food. The other choices, B: Larynx, C: Trachea, and D: Esophagus, are all structures found in the lower respiratory tract or digestive system. The larynx is commonly known as the voice box, the trachea is the windpipe that connects the larynx to the bronchi, and the esophagus is part of the digestive system that connects the throat to the stomach. Therefore, the pharynx is the correct answer as it specifically belongs to the upper respiratory tract.

Correct Answer: A

Rationale: The primary role of hemoglobin in red blood cells is to carry oxygen. Hemoglobin binds to oxygen in the lungs and transports it to tissues throughout the body. This is essential for cellular respiration and energy production. Choices B, C, and D are incorrect because hemoglobin's main function is oxygen transport, not carrying nutrients, carbon dioxide, or waste products. Oxygen transport is crucial for the body's overall function and survival.

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.