BODY CAVITIES, DIAPHRAGM AND MESENTERIES 



I»I 



U-shaped cavity become confluent ventral to the heart. The result is a single, 

 large pericardial chamber, the long axis of which now hes in a dorse- ventral plane 



Esophagus 



Spinal cord 



Pericardial cavity 

 Vcniricte of heart 



Ventral mesocarJiiim 



Liver 



Ventral mesentery 



(falciform ligament) 



Dorsal mesocar- 

 dium 



h- Septum transfer sum 



Stomach 



B 



Ventral mesentery 



(lesser omentum) 



Dorsal mesogaslrmm 



Dorsal pancreas 



Mesentery 



Mesocolon 



Mesoreclum 

 Fig. 189.— Diagram showing the primitive mesenteries of an early human embryo in median sagittal sec- 

 tion. The broken lines (A, B, and C) indicate the level of sections A, B, and C in Fig. 190. 



Neural tube 



Notochord 



Neural tube 



Notochord 

 Postcar- . , 

 dimltein ""'"° 

 Dorsal mesenUry. 



Gut- 



Peritoneal 

 cavity \, 

 .Falciform 

 ligament 



Fig. 190. — Diagrammatic transverse sections. A, Through the heart and pericardial cavities of an early 

 human embryo; B, through the fore-gut and liver; C, through the intestine and peritoneal cavity. 



nearly at right angles to the plane of the pleuro-peritoneal cavities, and con- 

 nected with them dorsally by the right and left pleuro-peritoneal canals. 



The division of the primitive ccelom into separate cavities is accomphshed by 



