secondary pulmonary lobule


Also found in: Dictionary, Thesaurus, Encyclopedia.
Related to secondary pulmonary lobule: primary pulmonary lobule

sec·on·dar·y pul·mo·nar·y lob·ule

a pyramidal mass of lung tissue with sides that are bounded by the incomplete interlobular connective tissue septa and with a base, which is 1-2 cm in diameter, which usually faces the pleural surface of the lung; lobules that occupy a more central position in the lung are not well defined and are considered to consist of three to five pulmonary acini with proximate terminal bronchioles.

secondary pulmonary lobule

A 1–2.5-cm structure which is the smallest unit of lung tissue invested by connective tissue septa, and contains 3 to 5 acini and 30 to 50 primary septa. Secondary pulmonary lobules are can usually be identified by high-resolution CT.

Secondary pulmonary lobule components
• Core structures—bronchiole, pulmonary artery, lymphatics, and axial, interstitium which together are known as the bronchoalveolar bundle;
• Septal structures—pulmonary venules, lymphatics and peripheral interstitum that forms septum;
• Parenchyma—composed of alveoli, the pulmonary capillary bed and the alveolar interstitium.

secondary pulmonary lobule

The smallest functionally complete unit in the lung. It is about 1 cm wide and 2 cm long, contains a few acini, and is connected to the bronchial tree by a small bronchiole. Each secondary pulmonary lobule is supplied by a pulmonary arteriole, pulmonary venule, and lymphatics and is separated from neighboring secondary pulmonary lobules by connective tissue septa.
See also: lobule
Full browser ?