Which respiratory division includes the larynx and respiratory structures distal?

Correct Answer: B

Rationale: The correct answer is B, lower respiratory tract. The larynx and structures distal to it, such as the trachea, bronchi, and lungs, are part of the lower respiratory tract. The upper respiratory tract (choice A) includes the nose, nasal cavity, pharynx, and larynx. Internal respiratory tract (choice C) is not a commonly used term in respiratory anatomy. Alveoli of the respiratory tract (choice D) specifically refer to the air sacs in the lungs where gas exchange occurs, not the entire respiratory division that includes the larynx and structures distal to it.

Correct Answer: A

Rationale: Step 1: Increased PO2 leads to higher oxygen levels in blood. Step 2: Higher PO2 causes hemoglobin to become fully saturated with oxygen. Step 3: Fully saturated hemoglobin stores more oxygen. Step 4: Therefore, as PO2 increases, saturation goes up and hemoglobin stores more oxygen. Other choices are incorrect because they do not align with the relationship between PO2, hemoglobin saturation, and oxygen storage in the blood.

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.