Three weeks later the student, together with the undertaker and relatives, went to the vault to view the remains. The body was in a perfect state of preservation, only for a large growth of beard as the student supposed. This student had observed rightly, but he did not go far enough. He did not think of how the hair actually got its nourishment. The hair owes its life to the circulation of the blood, just as much as the heart or any other organ does, and will die and cease to grow just as soon as the body dies and the circulation is cut off. What this student saw was only an apparent growth, for after the body dies the tissues begin to shrink, squeezing the blood and fluid substances out of them, thus giving the hair cylinder a more projected appearance.
The student was very much surprised at his mistake, but after the explanation he saw that the hair owed its life to the circulation and that when this circulation was cut off, the hair must cease to grow.
The chief function of hair is that of protection from heat or cold and to help shield the brain from the effect of a blow upon the head.
The hair, next to the teeth and bones, is the least destructible part of the body.
The Fascia.
—The fascia (fascia, a bandage) is areolar or aponeurotic tissue of variable thickness and strength found in all regions of the body and invests or surrounds the softer and more delicate organs. From its situation in the body the fascia is divided into two groups, superficial and deep.
Superficial fascia is found immediately beneath the skin over almost the entire surface of the body. It connects the skin with the deep fascia and consists of areolar tissue.
The superficial fascia varies in thickness in different parts of the body and some places, especially in the groin is capable of being subdivided into several different layers. The first layer of the superficial fascia, which is just beneath the skin, usually contains a great amount of fat or adipose tissue. This, in most text books, has been termed the subcutaneous tissue. The second layer is comparatively devoid of adipose or fatty tissue and in this we find the trunks of the subcutaneous vessels and nerves, as for example, the radial and ulnar veins in the arms and the saphenous vein in the leg.
The superficial fascia facilitates the movement of the skin, serves as a soft medium for the passage of the vessels and nerves to the skin and retains the warmth of the body, since the fat contained in its meshes is a had conductor of heat.
Deep fascia or aponeurotic fascia is a dense inelastic, unyielding fibrous membrane, forming a sheath for the muscles and affording them broad surfaces for attachment. On removal of the superficial fascia, the deep fascia is usually exposed and can be seen as a dense, tough membrane, which not only binds down the muscles to each region, but gives to each a separate sheath as well as to the blood vessels and nerves.