Body cavities Sanjaya Adikari Department of Anatomy

Amniotic cavity Secondary yolk sac Extra-embryonic coelom (chorionic cavity) Connecting stalk

Folding of the embryo Ventral mesentary Dorsal mesentary RL

Mesentery Formation of ventral and dorsal mesenteries divides the coelom into right and left components Most of the ventral mesentery breaks down and cause confluence of right and left halves Ventral mesentery persists in the region of the developing stomach and the liver –Ventral mesogastrium (lesser omentum) –Falciform ligament

Peritoneal cavity Diaphragm separates the peritoneal cavity from the pleuropericardial cavity above

Mesentary

mesentery peritoneum retro-peritoneal cavity

Pleural and pericardial cavities

Pleural and pericardial cavities… cont. Pleuropericardial folds separate the pleural and pericardial cavities Initially the pericardial cavity lies anteriorly Later, due to extensive growth of the lungs, the pleural cavities expand on either side to grow over the pericardial cavity