Quizlet HESI A2 Anatomy and Physiology

Correct Answer: A

Rationale: The correct answer is A: To transmit signals and coordinate body activities. The nervous system is responsible for sending and receiving signals throughout the body to regulate various functions and coordinate activities. This includes sensory perception, motor responses, and communication between different parts of the body. The other choices are incorrect because the immune system (B) fights infections, the endocrine system (C) produces hormones, and the thermoregulatory system (D) regulates body temperature, which are functions separate from the primary role of the nervous system.

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: A

Rationale: The correct answer is A: Pineal gland. The pineal gland is located in the brain and is responsible for producing melatonin, which regulates sleep-wake cycles. Melatonin is not produced by the thyroid gland (B), pituitary gland (C), or adrenal gland (D). The thyroid gland produces hormones that regulate metabolism, the pituitary gland regulates various hormones, and the adrenal gland produces hormones like cortisol and adrenaline. Therefore, the pineal gland is the correct answer as it specifically produces melatonin.

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: 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.