Haldane effect refers to

Correct Answer: A

Rationale: The correct answer is A: Increased CO2 uptake to minimize CO2 tension. The Haldane effect describes how the blood's ability to carry CO2 increases as oxygen levels decrease. When oxygen binds to hemoglobin, it displaces CO2, allowing more CO2 to be carried by the blood. This phenomenon is crucial in the exchange of gases in the lungs and tissues. Choice B is incorrect as the Haldane effect is related to CO2, not O2 tension. Choice C is incorrect as the Haldane effect leads to increased CO2 uptake, not decreased. Choice D is incorrect as it states decreases O2 tension, which is not directly related to the Haldane effect.

Correct Answer: B

Rationale: The correct answer is B: Discard the specimen and assist the patient in obtaining another specimen. It is important to discard the sputum specimen because it has been sitting for 4 hours, which could lead to contamination and inaccurate test results. The nurse should assist the patient in obtaining a fresh specimen to ensure accurate testing. Choice A is incorrect because taking the old specimen to the lab could lead to inaccurate results. Choice C is incorrect because refrigerating the old specimen won't prevent contamination. Choice D is incorrect because adding saline to the old specimen can alter its composition and lead to inaccurate test results.

Correct Answer: A

Rationale: The correct answer is A because even though the patient has normal hemoglobin levels, the significantly decreased SaO2 and PaO2 levels indicate that the hemoglobin is not effectively carrying oxygen to the tissues. This leads to a situation where the tissue demands for oxygen may be met at baseline, but the patient will be unable to respond to physiological stressors that require increased oxygen delivery. Choice B is incorrect because it focuses on short-term oxygen needs and CO2 expulsion, which are not directly related to the implications of the oxyhemoglobin dissociation curve in this case. Choice C is incorrect because decreased SaO2 and PaO2 levels would lead to tissue hypoxia, which would likely result in sensations of shortness of breath or labored breathing as the body tries to compensate for the lack of oxygen. Choice D is incorrect because decreased PaO2 levels would not lead to respiratory alkalosis. The body would likely try to compensate by increasing respiratory rate to improve oxygenation.

Correct Answer: D

Rationale: The correct answer is D: anatomic dead space. Anatomic dead space refers to the air in the conducting passages (such as trachea, bronchi) that does not reach the alveoli for gas exchange. This space only serves as a pathway for air to move in and out of the lungs. Vital capacity (A) is the maximum amount of air that can be exhaled after a maximum inhalation. Minimal volume (B) is not a recognized term in respiratory physiology. Residual volume (C) is the amount of air left in the lungs after a maximal exhalation and is not specifically related to the air in conducting passages.

Correct Answer: A

Rationale: The correct answer is A, during external respiration. Oxyhemoglobin forms when oxygen binds to hemoglobin in the lungs during external respiration. This process occurs in the alveoli where oxygen diffuses from the air sacs into the blood, binding with hemoglobin to form oxyhemoglobin. Choices B, C, and D are incorrect because oxyhemoglobin formation specifically happens during external respiration, not immediately after carbon dioxide enters the blood, when the chloride shift occurs, or during pulmonary ventilation. These processes are important in respiration but do not directly involve the formation of oxyhemoglobin.