Quizlet HESI A2 Anatomy and Physiology

Correct Answer: B

Rationale: The correct answer is B: To exchange gases. Alveoli are tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide takes place. Oxygen from the air we breathe enters the blood through the alveoli, and carbon dioxide is removed from the blood and exhaled. This process is essential for respiration. Explanation of other choices: A: To filter blood - This is incorrect because the alveoli do not filter blood. Filtering of blood primarily occurs in the kidneys and liver. C: To transport nutrients - This is incorrect because the alveoli are not involved in transporting nutrients. Nutrient transport mainly occurs through the bloodstream. D: To store oxygen - This is incorrect because the alveoli do not store oxygen. Oxygen is temporarily stored in the red blood cells and muscle tissues.

Correct Answer: B

Rationale: The correct answer is B: Absorbing nutrients. The small intestine is where the majority of nutrient absorption occurs in the digestive system. Its long and highly folded structure provides a large surface area for nutrients to be absorbed into the bloodstream. This process is essential for the body to obtain the necessary vitamins, minerals, proteins, and other nutrients from food. Breaking down fats (choice A) primarily occurs in the small intestine but is not its primary function. Secreting digestive enzymes (choice C) is the role of the pancreas and liver, while storing bile (choice D) is the function of the gallbladder.

Correct Answer: B

Rationale: The correct answer is B: To break down food. The primary role of the stomach is to mechanically and chemically break down food into smaller particles through the action of stomach acid and enzymes. This process prepares the food for further digestion in the small intestine. Incorrect choices: A: To absorb nutrients - This is not the primary role of the stomach. Nutrient absorption primarily occurs in the small intestine. C: To secrete digestive enzymes - While the stomach does secrete digestive enzymes, its primary role is not just to secrete them but to use them to break down food. D: To store glucose - The stomach does not store glucose. Glucose storage primarily occurs in the liver and muscles.

Correct Answer: B

Rationale: The primary function of the circulatory system is to transport oxygen and nutrients throughout the body. The heart pumps blood containing oxygen and nutrients to all cells and tissues. This process supports cellular functions and provides energy. Hormone production (A) is mainly regulated by the endocrine system. Fighting infections (C) is primarily the role of the immune system. Regulating body temperature (D) is primarily controlled by the thermoregulatory system. Overall, the circulatory system's main role is the transport of oxygen and nutrients, making choice B the correct answer.

Correct Answer: B

Rationale: The correct answer is B: To protect the body from external damage. The skin acts as a physical barrier, preventing harmful substances from entering the body and protecting internal organs. It also helps regulate body temperature to some extent, but that is not its primary function. The skin does not produce vitamin D; this is mainly done by the liver and kidneys. Red blood cells are produced in the bone marrow, not the skin.