Fissures & Lobes Of Lungs

FISSURES & LOBES OF LUNGS

FISSURES

• The oblique fissure (in both right & left lungs) cuts into the whole thickness of the lung, except at the hilum.
• It passes obliquely downward & forwards, crossing the posterior border of lung about 6 cm below the apex & the inferior border of lung about 5 cm from the median plane.
• In the right lung, horizontal fissures passes from the anterior border of lung to the oblique fissure & sepaeates a wedge-shaped middle lobe from the upper border.
• The fissure runs horizontally at the level of 4th costal cartilage & meets the oblique fissure in the midaxillary line.
• The tongue-shaped projection of the lung below the cardiac notch is called lingula.
• It corresponds to the middle lobe of the right lung.

Surface marking of fissures

OBLIQUE FISSURE can be drawn by joining:

1. A point 8 cm lateral to 3rd thoracic vertebra.
2. Another point on the 5th rib in mid axillary line.
3. A third point on the 6th costal cartilage 7.5 cm from the median plane.

HORIZONTAL FISSURES is represented by a line joining:

1. A point on the anterior border of the right lung at the level of the fourth costal cartilage.
2. A second point on the fifth rib in the midaxillary line.