Question

How many lobes are present in the left lung?
A) 3
B) 4
C) 2
D) 1

Answer 1

Hint:The lungs are the organs that facilitate the process of breathing in mammals. In humans, both the lungs are enclosed within fluid filled sacs called the pleural sac.

Complete answer:
Humans have two lungs, the left lung and the right lung which are present on either side of the mediastinum in the chest. Both the lungs are not equally sized with the right lung being larger and heavier compared to the left lung. The difference in their sizes exists to make space for the heart in the chest cavity and because the heart is tilted to the left side, the left lung is smaller than the right.
Similar to difference in size, the lobular structure of each lung is also different. The right lung has an oblique fissure along with a transverse (or horizontal) fissure which divides it into three lobes, the superior, middle and inferior lobes whereas the left lung only has an oblique fissure which separates it into two lobes, the superior and the inferior lobe. Therefore, the lungs have a total of five lobes, three in the right lung and two in the left lung.
The following diagram will help in visualizing the lobes of the lungs.

Due to the presence of an oblique fissure in the left lung, it is divided into two lobes. Therefore, this option is correct.

Therefore, the correct answer is option (C) 2.

Note: The lobes are further subdivided into bronchopulmonary segments depending upon the number of segmental bronchi in each lobe. There are a total of 10 bronchopulmonary divisions of the lungs.