14 



(c) The left subclavian artery, corresponding in its distribution to the 



right subclavian artery. 



(d) The intercostal arteries, (several pairs of small arteries). 



(e) The coeliac artery, dividing into the hepatic artery and the lieno- 



intestinal artery. 

 (/) The anterior mesenteric artery, dividing into numerous branches. 

 {g) The renal arteries, passing each to the hilum of a kidney. 

 (h) The spermatic or ovarian arteries. 

 (i) The posterior mesenteric artery. 

 (j) The lumbar arteries. 

 (k) The median sacral artery. 

 (I) The common iliac arteries, formed by the bifurcation of the aorta, 



running to the hind limbs as the femoral arteries. Each gives 



off in the abdomen — 



(1) The ilio-lumbar artery. 



(2) The internal iliac artery, and 



(3) The vesical artery. 



The pulmonary artery. (See above, p. 10, 2, (b).) 



F- Dissection of the Heart. 



Remove the heart from the body by cutting through the gre%,t vessels about 

 half an inch from the heart. 



1. The auricles. Expose the cavities of both auricles by cutting away their 



outer walls. 



(1) The right auricle. Note the thin wall, thicker in the appendix, 



and marked by muscular ridges ; note also — 



(a) The openings of the three venae cavae. 



(b) The Eustachian valve between the openings of the left superior 



vena cava and the inferior vena cava. 



(c) The septum auricularum with the fossa ovalis. 



(d) The right auriculo-ventricular opening. 



(2) The left auricle. Note the thin wall, thicker in the appendix. 



(a) The openings of the pulmonary veins. 

 (6) The left auriculo-ventricular opening. 



(c) The coronary sinus (the dilated portion of the coronary vein), 

 embedded in the posterior wall of the left auricle. 



2. The ventricles. 



Make a transverse section of the ventricles, about one third of an inch from 

 the apex. Note the shape of the cavities of the ventricles and the relative 

 thickness of their walls. 



(1) The right ventrical. Remove its outer wall, and note — 



(a) The tricuspid valve of the right auriculo-ventricular opening, 

 formed of three membranous flaps attached to its margin ; 

 the chordae tendineae passing from these flaps to the muscular 

 processes of the walls of the ventricle. 



