Physiology, hygiene and sanitation, an elementary textbook of physiology, with special attention given to hygiene and sanitation (1919) (14578567898)

Identifier: physiologyhygien00heiz (find matches)
Title: Physiology, hygiene and sanitation, an elementary textbook of physiology, with special attention given to hygiene and sanitation
Year: 1919 (1910s)
Authors: Heizer, W. L. (W. Lucien), b. 1880
Subjects: Physiology Hygiene Sanitation
Publisher: Louisville, Ky., C.T. Dearing Printing Co., Incorporated
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress



Text Appearing Before Image:
m the nails. Hair is a simi-lar modification of skin. At the entrances into the body theskin changes its structure and joinsa more delicate and thinner lining,the mucous membrane. Functions of the Skin. Aside fromits use in giving a finish and beautyto the body, it has four distinct func-tions. First, it forms a protectivecoating for the delicate blood vessels,glands and nerves; second, it is theseat of feeling by which we are madeaware of pain, heat, weight, and cold;third, it aids in regulating the heatof the body, and, fourth, it aids thelungs, bowels, and kidneys in remov-ing wastes from the body. Structure of the skin. The skin is composed of twolayers; the outer, horny layer, the epidermis and the inner,delicate one, the dermis or true skin. The epidermis has nosensitive nerves or blood vessels and is thick enough to pro-tect the delicate layer beneath. Who has not burned ablister on the hand? The elevated layer which fills withwater (serum) is the epidermis. A needle may be 23i
Text Appearing After Image:
Fig-. 118.—Stucture ofskin. A. Epidermis.B. Dermis. (Great-ly magnified.) 238 PHYSIOLOGY, HYGIENE AND SANITATION pushed through this layer without pain, but if the delicatedermis below is touched, pain is at once felt. Corns are thickened spots of epidermis and are causedby rubbing or friction. Shoes that are too loose, ill-fitting,or too tight often produce corns. The horny hands ofa working man are made so by constant friction of tools inthe hands. The epidermis is constantly be-ing worn away, and is as rapidlyrestored, by the growth of cells inthe dermis. Complexions of the skin are dueto the amount of coloring matterfound in the epidermis. The colorof different races of people is de-termined by the kind and amountof this coloring matter. The negrois dark or black for this reason. The dermis is plentifully sup-plied with nerves and blood vesselswhich end in tiny projectionscalled papillae. The epidermis fits and is closelymoulded upon these ridges. Thenerve papillae are most nume