THE VENOUS SYSTEM. 543 



II. The systemic arch, the median one of the three, 

 corresponding to the second efferent branchial in 

 the tadpole, gives off- 

 the laryngeal artery to the larynx, 

 the cesophageal to the oesophagus, 

 the occipito-vertebral to the head and vertebral 



column, 



the subclavian to the fore limb. 



From the left aortic arch, just as it unites with its fellow 

 of the other side to form the dorsal aorta, or from 

 the beginning of the dorsal aorta, there is given off 

 the cceliaco-mesenteric to the stomach, intestine, 

 liver, and spleen. 

 Further back the dorsal aorta gives off 



the renal arteries to the kidneys, and the genital 



arteries to the reproductive organs ; 

 the inferior mesenteric to the large intestine ; 

 Then it divides into two iliacs, each of which supplies 

 the bladder (hypogastric), the ventral body wall 

 (epigastric) and the leg (sciatic). 



III. The pulmo-cutaneous arch, the most posterior, 

 corresponding to the fourth efferent branchial in 

 the tadpole, gives off 



the cutaneous artery to the skin, 

 the pulmonary artery to the lungs. 



The Venous System. 



I. Each superior vena cava is formed from the union of 

 three veins, and each of these three is formed from two 

 smaller vessels. 



-p, , i ( Lingual from the mouth and 



tongue. 



\ Mandibular from the lower jaw. 

 r Internal jugular from the inside 



Superior 

 vena cava. 



Innominate. 



of the skull. 



Subscapular from the back of 

 the arm and the shoulder. 



{Brachial from the arm. 

 Musculo-cutaneous from the 

 skin and sides of the body. 



