238 GENERAL ANATOMY. 



and its dependences the name of circulatory apparatus is given; 

 the second name relating to the formation, and the first to the 

 function. 



This system comprehends three species of organs, two of 

 which, the arteries and the veins, contain blood ; the arteries 

 convey it to every part of the body, and the veins bring it 

 back from these parts; the arteries and veins are united at the 

 centre by means of a hollow and muscular organ, the heart. 

 The third species, the lymphatic vessels, convey, not blood, 

 but chyle and lymph, and pour them into the veins; they 

 should be considered as an appendage of the venous system. 



349. The arteries and the veins are in such relation with 

 the heart and the blood, that they may be farther divided into 

 two other sections. 



The blood is brought by the veins from all parts of the 

 body to the heart, and hence conveyed to the lungs by the 

 pulmonary artery; it returns from the lungs by the pulmona- 

 ry veins to the heart, hence to be conveyed by the aorta to 

 every part of the body, from which it is brought back again 

 by the venae cavae. The name of pulmonary, or small circula- 

 tion, is given to the short circuit of the blood from the heart to 

 the lungs and from the lungs to the heart, and the name of pul- 

 monary vessels to the tubes, which give rise to this circulation. 

 The name of general or great circulation is given to the course 

 of the blood from the heart to all parts of the body, and from 

 these parts to the heart, and the name of aorta and of venae 

 cavae, or of general vessels, to those that are traversed by the 

 blood in this circle. 



350. The blood contained in the general veins of the body, 

 in the anterior or right side of the heart and in the pulmonary 

 artery, is of a brownish red colour; it is called venous: that 

 which is contained in the pulmonary veins, the other half of 

 the heart and the aorta and its branches, is of a vermilion or 

 arterial red. Circulation has also been divided, according to 

 the blood that it contains, into that of black blood and into 

 that of red blood. Bichat, author of this division, which had 

 been perceived by Galen (sect, ii.), has thought proper to 

 describe the first mentioned part of the circulation, under the 



