The Vascular System 



213 



Aed 



arches arises the most anterior of seven or eight 

 pairs of lumbar 

 arteries, lu 1-7; 

 this first lumbar 

 artery is contin- 

 ued cephalad for 

 some distance as 

 a longitudinal 

 trunk that gives 

 off several lateral 

 branches to the 

 walls of the thor- 

 acic region. The 

 other six or seven 

 lumbars are dis- 

 tributed to the 

 dorsal body wall, 

 and arise, at 

 more or less reg- 

 ular intervals, as 

 farcaudadasthe 

 .sacrum, or even 

 back of that 

 point. 



The first large 

 branch oft he FlG ' 6l< The arteries of the P sterior 



region of the Florida alligator. For lettering, 



aorta is the un- see pages 224-25. 

 paired me s en- 

 teric artery, m 1 , which is given off in about 

 the region of the fourth pair of lumbars; it 



