32 MANUAL FOR STABLE SERGEANTS. 



68. Arteries are strong thick- walled tubes which carry the blood 

 from the heart to all parts of the body. They give off branches and 

 subdivide until they terminate in the capillaries. 



FIG. 15. Circulatory apparatus. 1, Heart (right ventricle); 2, heart (left ventricle) 

 3, heart (left auricle); 3a, heart (right auricle); 4, pulmonary arteries (cut off); 

 5, pulmonary veins (cut off); 6, anterior aorta; 7, common carotid artery; 9, left 

 brachial artery; 13, humeral artery; 14, radial artery; 15, metacarpal artery; 16; 

 digital artery; 17, posterior aorta; 18, branches distributed to the stomach, spleen; 

 pancreas, etc.; 19, branches distributed to the intestines; 20. branch to the kidneys; 

 22, posterior vena cava; 24, external iliac artery; 25, internaliliac artery; 27, femoral 

 artery; 28, posterior tibial artery; 29, metatarsal artery; 30, venous network of the 

 foot; 33, jugular vein; 34, anterior vena cava. 



69. Capillaries are small, thin-walled vessels that are just large 

 enough to permit the passage of the blood corpuscles. In these 

 vessels occurs the exchange of substances between the blood and 

 the tissues, the tissues being supplied with oxygen and nutritious 



