42 LABORATORY OUTLINES FOR EMBRYOLOGY 



unite to form the ascending vena cava. From the kid- 

 neys, ventral to the renal arteries, the ascending vena 

 cava receives the renal veins. Trace the ascending vena 

 cava to the diaphragm. How does the blood from the 

 umbilical vein get into it? Where does the blood from 

 the intestine go? 



Draw a diagram of the circulation thus far worked out 

 and label all the parts. 



h. The Thorax 



What blood vessels pass through the diaphragm? 

 The oesophagus extends from the stomach through the 

 diaphragm into the thorax. Separate the diaphragm 

 from the body wall. The masses of tissue occupying 

 the greater part of the thoracic cavity are the lungs. 

 How many lobes? Size? Shape? Position? 



What is the position of the heart? Size? Shape? 

 The heart is enclosed in a thin connective tissue sac, the 

 pericardium. The point of the heart is called the 

 apex and the other end is called the base. The firm, 

 muscular part of the heart composes the ventricles and 

 the darker colored, softer portion at the base composes 

 the auricles. Both the auricles and ventricles are called 

 right and left, according to their position. Trace 

 the aorta to the heart. Where does it enter the heart? 

 How many arches has the aorta now? The artery lead- 

 ing from the ventricle to the lungs is the pulmonary 

 artery. Which ventricle? What is the relation of the 

 pulmonary artery to the lungs? From the anterior part 

 of the arch of the aorta arises a vessel which carries the 



