Oblique Fissure is an important component of the structure of the lungs. It is also known as the Major Fissure. It is present in the right lung as well as the left lung.
The main purpose of Oblique Fissure is to divide the inferior lobe of both the lungs from the rest of the lung. It divides the inferior lung and the middle lobe in the right lung whereas in the left lung it divides the inferior love and the superior lobe.
They start from the surface of the lung and reach the hilum. It helps in greater transmission of diaphragmatic excursions. Thus, the upper lobe in each lung can expand much greater than the diameter of the pleural cavity.