Which of these factors does not affect hemoglobin's affinity for oxygen?

Correct Answer: C

Rationale: The correct answer is C: electrolyte balance. Hemoglobin's affinity for oxygen is primarily influenced by factors such as pH, temperature, and the partial pressure of oxygen (PO2). Electrolyte balance, on the other hand, does not directly impact hemoglobin's ability to bind with oxygen. Changes in electrolyte levels may affect overall blood composition but do not directly alter hemoglobin's oxygen-binding capacity. Therefore, electrolyte balance does not affect hemoglobin's affinity for oxygen, making it the correct choice. RBC metabolic activity can impact oxygen release from hemoglobin, temperature can affect hemoglobin's oxygen-binding capacity, and the PO2 of blood directly influences oxygen binding to hemoglobin.

Correct Answer: C

Rationale: The correct answer is C: Smoking. Smoking is a risk factor for developing heart failure because it damages the blood vessels, increases blood pressure, and reduces oxygen delivery to the heart. Regular exercise (A) is actually beneficial for heart health. Low blood cholesterol levels (B) are generally considered a positive factor for heart health. Adequate sleep (D) is important for overall well-being but is not a direct risk factor for heart failure. In conclusion, smoking (C) stands out as the correct answer due to its harmful effects on the cardiovascular system.

Correct Answer: C

Rationale: The larynx consists of 9 cartilages, including the thyroid, cricoid, and epiglottis. These structures provide support and protection to the vocal cords and are essential for phonation and breathing. Choice C is correct because it accurately reflects the number of cartilages in the larynx. Choices A, B, and D are incorrect as they do not correspond to the anatomical structure of the larynx. It is important to understand the specific components of the larynx to correctly identify the number of cartilages present.

Correct Answer: A

Rationale: Step 1: Pleura is a thin membrane that surrounds the lungs and lines the chest cavity. Step 2: There are two layers of pleura - visceral (inner layer covering the lungs) and parietal (outer layer lining the chest cavity). Step 3: The correct answer is A (2), because there are only two layers of pleura. Summary: Choice B and C are incorrect because they each represent only one layer of pleura, whereas the correct answer A encompasses both layers. Choice D is incorrect because it includes all options, which is not accurate in this case.

Correct Answer: D

Rationale: The correct answer is D: A bartender. Bartenders are not typically exposed to occupational lung hazards like smoke, dust, or chemicals. Firefighters (A), cotton gin workers (B), and construction contractors (C) are all at increased risk due to exposure to smoke, cotton dust, and construction materials, respectively. As a result, the bartender is the least likely to develop an occupational lung disorder compared to the other professions listed.