Trace the dorsal aorta backwards and note that it passes between 

 the kidneys, to each of which it gives off four renal arteries and then 

 it divides posteriorly into an iliac artery to each leg. The iliac artery 

 is continued backwards as the femoral artery in the leg. 



3. The pulmo-cutaneous arch gives off : — 



(a) A pulmonary artery, running along the outer side of the whole 



length of the lung. 



(b) A cutaneous artery, which at first runs forwards and upwards, 



and then turns backwards, supplying the skin of the back and 

 the sides of the head.] 



Make a complete sketch of the arterial system. 



Carotid gland 









I. Carotid 





l^hyrold^ 

 IB gland M 



I Ungual 

 Carotid gland 



Pulmocuuneous 

 arch 



Pulmocutanaous V^ 

 arch -^** 



_ / Carotid arch 



\^^^- Carotid 

 -. ^^--Cutaneout 



^.-CutUMOut 



Pulmonary — \tXi 





|Jy X Occipito-vertehral 

 *6 \aaaaaaaaaa*- Subclavian 



- ~ Pulmonary 



Lung.... (A 





M Syataroic arch 



Coellaco- mesenteric 



Fig. 7. — Arterial System of Xenopus and Rana. 



Cut out the heart, leaving attached to it as much as possible of the large 

 vessels. 



Note the sinus venosus, truncus arteriosus, auricles, and ventricle. 



Open the auricles and observe the division between them and the openings 

 of the veins passing into them. 



Make a section through the auricles and ventricle noting the thick muscular 

 walls of the ventricle and the valves between it and the auricles. 



22 



