, INTRODUCTION
• Lungs – enclosed in serous sac–
pleural cavity
• Pleura
• Delicate serous membrane
• Lines pleural cavity
• Two layers
• Inner visceral pleura – Covers
lungs
• Outer parietal pleura – Lines
thoracic wall and mediastinum
• Both layers of pleura continuous with
each other at hilum of lung and along
pulmonary ligament Human Anatomy/Yogesh Sontakke 3
,Human Anatomy/Yogesh Sontakke 4
, Embryological Aspects of Pleural
Cavities
• During embryonic life, fetus has two pleural
sacs (initially called pericardioperitoneal
canals)
• Each developing lung bud invaginates one
pleural sac and gets covered by two layers of
pleural sac
• Later, lung bud expands – form lung and start
occupying pleural sac
• Layer of pleural sac covering lung forms
visceral pleura, whereas outer layer forms
parietal pleura Human Anatomy/Yogesh Sontakke 5
• Lungs – enclosed in serous sac–
pleural cavity
• Pleura
• Delicate serous membrane
• Lines pleural cavity
• Two layers
• Inner visceral pleura – Covers
lungs
• Outer parietal pleura – Lines
thoracic wall and mediastinum
• Both layers of pleura continuous with
each other at hilum of lung and along
pulmonary ligament Human Anatomy/Yogesh Sontakke 3
,Human Anatomy/Yogesh Sontakke 4
, Embryological Aspects of Pleural
Cavities
• During embryonic life, fetus has two pleural
sacs (initially called pericardioperitoneal
canals)
• Each developing lung bud invaginates one
pleural sac and gets covered by two layers of
pleural sac
• Later, lung bud expands – form lung and start
occupying pleural sac
• Layer of pleural sac covering lung forms
visceral pleura, whereas outer layer forms
parietal pleura Human Anatomy/Yogesh Sontakke 5
