General Hygiene (Paperback)

This historic book may have numerous typos, missing text, images, or index. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. 1913. Not illustrated. Excerpt: ... CHAPTER IX CIRCULATION OF BLOOD Use of Blood. -- The cells of the body eat, breathe, and grow, like separate microscopic animals outside of the body. They cannot go in search of food and oxygen, but everything which they need is brought to them by a red liquid that is always flowing through every part of the body. This liquid is the blood. The blood also takes away the waste matters which the cells give off, and it protects the cells from disease germs which may enter the flesh. The life of the body depends upon the blood. Composition of Blood. -- Blood consists of a clear, yellow liquid called plasma, or serum, which is full of cells called blood cells, or corpuscles. About one half of the blood is plasma, and the other half is blood cells which float in the plasma. Plasma. -- The plasma of the blood consists of water containing protein, fat, sugar, and minerals, all of which are to become food for the cells of the body. It also contains small quantities of waste matters which it has washed away from the cells. Clot. -- After blood flows from the body, it becomes solid, like jelly. Blood in a solid form is called a clot. The effect of clotting is to form a solid mass which will stop the bleeding in a cut or wound. Red Blood Cells. -- Most of the cells which float in the blood are red, and give the red color to the blood. They may easily be seen by examining a thin Red bloo