CIRCULATION OF THE BLOOD. 47 



Pathological conditions of the Blood. 



1. Plethora increase in the volume or quantity of blood. 



2. Anemia deficiency of red globules with increase of water. 



3. Leticocythemia increase of white and diminution of red corpuscles. 



4. Glycohamia excess of sugar in the blood. 



5. Urcemia increase in the amount of urea. 



6. Cholesteramia an excess of cholesterine in the blood. 



7. Thrombosis and embolism clotting of blood in the vessels and 

 dissemination of coagula. 



8. Lipcemia an excess of fat. 



9. Melanczmia pigment in the blood. 



CIRCULATION OF THE BLOOD. 



The Object of the Circulation is to distribute nutritious blood to all 

 portions of the system and to carry waste materials from the tissues to the 

 various eliminating organs. 



The Circulatory Apparatus consists of the heart, arteries, capillaries 

 and veins. 



The Heart is a hollow, muscular organ, pyramidal in shape, measuring 

 5^ inches in length and weighing from 10 to 12 ozs. in the male, and 8 

 to 10 ozs. in the female. It is invested externally by a closed fibro- serous 

 sac, the pericardium, containing a small amount of fluid, which prevents 

 friction as the visceral and parietal layers glide over each other, during the 

 movements of the heart and lungs. 



The heart consists of four cavities, a right auricle and ventricle, and a 

 left auricle and ventricle, completely separated by a vertical partition. 

 The right is the venous side, receiving the blood from the venae cavee, and 

 propelling it through the pulmonary artery into the lungs ; the left is the 

 arterial side, receiving the arterial blood from the lungs by the pulmonary 

 veins, and propelling it through the aorta to the system at large. 



The Auriculo-ventricular orifices are guarded on the right and left sides 

 by the tricuspid and mitral valves respectively, while they are so arranged 

 as to permit the flow of blood in the forward direction only; the orifices of 

 the pulmonary artery and aorta are guarded by the semilunar valves. 



The Endocardium is a delicate, shining membrane, lining the interior of 

 the heart, and continuous with the lining membrane of the blood vessels. 



The walls of the left ventricle are nearly half an inch in diameter, being 

 two or three times thicker than the walls of the right; the force of its 

 contraction is, therefore, much greater. 



