Food and drink are prevented from entering the respiratory passageways during swallowing by means of the

Correct Answer: C

Rationale: The correct answer is C: epiglottis. During swallowing, the epiglottis covers the opening of the larynx to prevent food and drink from entering the respiratory passageways. It acts as a lid that directs food and liquids to the esophagus instead of the trachea. The glottis (choice A) is the space between the vocal cords, the pharynx (choice B) is the passageway for food and air, and the larynx (choice D) contains the vocal cords. The epiglottis specifically functions to protect the airway during swallowing.

Correct Answer: B

Rationale: The correct answer is B (2, 4) - cardiovascular system and respiratory system. The cardiovascular system transports O2 from the lungs to the cells and carries CO2 away for elimination by the respiratory system. The respiratory system is responsible for gas exchange, bringing O2 into the body and removing CO2. The other choices are incorrect because: A (3, 5) - The urinary system (3) filters waste from the blood and maintains fluid balance, while the endocrine system (5) regulates hormones and metabolism; neither directly supply O2 or eliminate CO2. C (1, 2) - The digestive system (1) processes food and absorbs nutrients, not involved in gas exchange; the cardiovascular system (2) does cooperate but alone is not sufficient. D (1, 2, 2004) - Choice 2004 is incorrect as it is not a valid option.

Correct Answer: A

Rationale: The correct answer is A because expiration involves the relaxation of the diaphragm and intercostal muscles. During expiration, the diaphragm moves up and the intercostal muscles relax, causing the thoracic cavity to decrease in volume. This increase in pressure forces air out of the lungs. Choice B is incorrect as it describes the process of inspiration, not expiration. Choice C is incorrect because expiration involves both the diaphragm and intercostal muscles, not just the diaphragm muscles. Choice D is incorrect as the intercostal muscles also relax during expiration, rather than contracting.

Correct Answer: A

Rationale: The correct answer is A: A type of bacteria. Tuberculosis is caused by Mycobacterium tuberculosis, a type of bacteria. This bacterium infects the lungs and can spread to other parts of the body. The other choices (B: A virus, C: A protozoan, D: Malnutrition) are incorrect because tuberculosis is specifically caused by a bacterial infection, not a virus, protozoan, or malnutrition. Bacteria can be identified through specific staining techniques and culture methods, distinguishing them from viruses and protozoa. Malnutrition is a risk factor for developing tuberculosis but is not the direct cause of the disease.

Correct Answer: B

Rationale: The correct answer is B (21%). Room air contains approximately 21% oxygen. By removing the supplemental oxygen, the client is now breathing the oxygen content present in the surrounding air. Choices A, C, and D are incorrect as they do not reflect the standard oxygen concentration in room air. Oxygen concentration in room air is typically around 21%, making choice B the most accurate option.