How many primary bronchi serve the left lung?

• A. None
• B. One
• C. Three
• D. Two

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the anatomy of the respiratory system. The trachea divides into two primary bronchi, one serving each lung. These bronchi are the main passageways for air to enter the lungs.
2. Step 2: Recall that the left lung is smaller than the right lung due to the position of the heart. This anatomical difference does not affect the number of primary bronchi serving each lung.
3. Step 3: Note that each lung is served by a single primary bronchus. The left lung is served by the left primary bronchus, and the right lung is served by the right primary bronchus.
4. Step 4: Eliminate incorrect options based on the anatomy. 'None' is incorrect because the left lung is served by a bronchus. 'Three' and 'Two' are incorrect because there is only one primary bronchus per lung.
5. Step 5: Conclude that the correct answer is 'One,' as the left lung is served by one primary bronchus.