The partial pressure of carbon dioxide in the interstitial space of peripheral tissues is approximately

Correct Answer: B

Rationale: The correct answer is B (45 mm Hg) because the partial pressure of carbon dioxide in the interstitial space of peripheral tissues is around 40-45 mm Hg. This value is higher than in the arterial blood (around 40 mm Hg) due to the production of CO2 by tissues. Choice A (35 mm Hg) is too low for interstitial CO2 levels. Choice C (55 mm Hg) and D (70 mm Hg) are too high and not consistent with normal physiological values. Overall, the correct answer aligns with the typical range of interstitial CO2 pressure in peripheral tissues.

Correct Answer: A

Rationale: The correct answer is A because at birth, when an infant takes their first breaths, blood flow to the lungs increases due to the expansion of the pulmonary vasculature. This allows for proper oxygenation of the blood. Choice B is incorrect as the resistance in the pulmonary arteries decreases to accommodate the increased blood flow to the lungs. Choice C is incorrect as changes in blood flow do cause the foramen ovale to close, ensuring proper circulation. Choice D is incorrect as air entering the alveoli is essential for oxygen exchange to occur in the lungs.

Correct Answer: A

Rationale: The correct answer is A: Electrocardiogram (ECG or EKG). An ECG is commonly used to assess heart function in heart failure because it provides information on the heart's electrical activity, rhythm, and any abnormalities. It can detect conditions such as arrhythmias, ischemia, and previous heart attacks. Other choices are incorrect: B (MRI) is more for imaging the structure of the heart, C (Colonoscopy) is for examining the colon, and D (Blood glucose test) is for measuring blood sugar levels, not heart function.

Correct Answer: C

Rationale: The correct answer is C: Corniculate cartilage. Corniculate cartilage is a paired cartilage found in the larynx, specifically at the apex of the arytenoids. The other choices, such as cricoid cartilage, epiglottis, and thyroid cartilage, are all unpaired cartilages. Cricoid cartilage is a complete ring, the epiglottis is a leaf-shaped cartilage, and the thyroid cartilage is the largest cartilage in the larynx. Therefore, Corniculate cartilage is the only paired cartilage among the options provided.

Correct Answer: C

Rationale: The phrenic nerve innervates the diaphragm and arises from cervical nerve roots C3 to C5. Choice C is correct as it accurately states that the phrenic nerve is located in the diaphragmatic area and originates from C3 to C5. Choice A is incorrect as it only mentions the diaphragmatic area without specifying the cervical levels. Choice B is incorrect as it only mentions the cervical levels without specifying the diaphragmatic area. Choice D is incorrect as the phrenic nerve does exist.