342 



THE VERTEBRATE BODY 



conus arteriosus is nearer the right side, so when the ventricle contracts 

 the blood with the dull-colored corpuscles goes out first, then we follow. 

 We pass the pulmocutaneous branch, but it is filled with the unoxygen- 

 ated blood so we continue into the second branch, the systemic arch 

 which carries us around to join the dorsal aorta running down the back. 

 We pass numerous branches leading off to the stomach, intestines, and 

 other internal organs, then enter one of the iliac arteries, leading to a leg. 



Carotid 



Innominate A. 

 Subclavian A. 

 Arch of aorta 

 Pulmonary A. 



Hepatic A 

 Coeliac A. 



Superior mesenteric 

 Renal A 

 Aorta 

 Inferior mesenteric 



Common iliac A . 



Fig. 23.10. The larger arteries of the human body. 



This continues down the leg as the sciatic artery, and we soon find our- 

 selves back in our original capillary. We manage to slip through a tiny 

 hole in the blood clot and again expand ourselves to our normal size. 



Never again can we look at a frog and think of it as a dull, uninterest- 

 ing creature when we recall the marvels that we have just witnessed. 

 Yet, as we look at our road maps (diagrams of the circulatory system, 

 Fig. 23.8 and Fig. 23.9), we notice that there are many other routes 

 which we could have taken that would have been just as interesting; 

 through the spleen, where we could have seen worn-out red corpuscles 

 removed for destruction ; through the intestines, to see food absorption ; 



