THE ni.OOI) SYSTEM 



Arisiiij; from the ventricle of the heart and passinn ohh<ni(ly 

 across the auricles is the large vessel, trunrus arteriosus, referred 

 to above. Note the divisions of the truncus arteriosiis into right 



Fig. 1 — DiAGUAM of thk Bloou Vessels of the Kroo. 

 This diaRrain is schematic and not intended to show details. 

 The capillary networks of various regions are represented as follows: 



A. C, arm; C. H. head; C. S., skin, L. C, leg. 



ARTERIES (unshaded) 



Main Vessels: — 



I. Carotid arch .supplying the head region. 

 II. Aortic arch supplying the arm-trunk-leg region. 

 III. Pulmo-cutaneous arch supplying the lung-skin region. 



Sul)ordinate Vessels: — 



.v. M., anterior mesenteric artery G., gastric artery 



B. A., subclavian artery Ge., genital artery 



C. \., cutaneous artery He., hepatic artery 



C. I., common iliac artery J., junction of aortic arches of 

 Coe., coeliac artery either side to form the dorsal 



C. M., coeliaco-mesenteric artery aorta 



D. A., dorsal aorta P. A., pulmonary artery 



¥. S., femoral and sciatic arteries P. M., posterior mesenteric art^-ry 

 T. A., tnmcus arteriosus Re., renal arteries 



VEINS (solid black) 



Main Vessels: — 



Po. C, post cava vein draining the trunk-leg region. 



Pr. C., precava vein draining the hcad-arm-skin region. 



P. Ve., pulmonary vein draining the lung. 



S. v., sinus venosus receiving blood from whole body except the lungs. 



Subordinate Vessels: — 



Br. V, brachial vein M C, musculo-cutaneous vein 



F.. femoral vein P. V., pelvic vein 



He. v.. hepatic vein Re. p., renal portal vein 



HeP., hepatic portal vein Sc, Sciatic vein 



V. Ab., Ventral abdominal vein 



HEART 

 L. A., left auricle; R. A.; right auricle; V., ventricle 

 Reed and Young "Laboratory Studies in Zoology." 



cutaneous artery may tlicn ])e seen, (h) The pulmonary artrrij, 

 following a somewhat wavy course along the outer side of the 



