HMS, BM EQ-Bank 58 MC

During a 400m sprint, an athlete's oxygen demand increases. Which sequence correctly shows the pathway of oxygen from inhalation to the working muscles?

Alveoli → Pulmonary vein → Left atrium → Left ventricle → Systemic circulation
Alveoli → Pulmonary artery → Left atrium → Left ventricle → Systemic circulation
Bronchi → Pulmonary vein → Right atrium → Right ventricle → Systemic circulation
Bronchi → Pulmonary artery → Right atrium → Right ventricle → Systemic circulation

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Consider Option A: Alveoli → Pulmonary vein → Left atrium → Left ventricle → Systemic circulation

This shows the correct pathway

Oxygen diffuses into the alveoli
Enters pulmonary veins (oxygenated blood)
Flows to left atrium then ventricle
Lastly entering systemic circulation to reach muscles

Other Options:

B is incorrect: Pulmonary arteries carry deoxygenated blood
C is incorrect: Right side of heart receives deoxygenated blood and bronchi are air passages not involved in blood flow
D is incorrect: Combines multiple errors – wrong blood vessels and wrong side of heart