(2) The shafts of the hairs.
c. True Scent Glands. A third type of gland associated with the integument is
the true scent gland. At least in older days, the product of these glands was supposed
to be attractive to the opposite sex. (Here, we are not referring to the body odor known
as BO. BO is a metabolic by-product produced by microorganisms located on the skin.
These microorganisms act upon residue from perspiration, left after the water has
evaporated.)
Section IV. FUNCTIONS OF THE INTEGUMENTARY SYSTEM
3-15. INTRODUCTION
The integumentary system forms the outermost covering of the human body.
Thus, it is the boundary between the organism and the ambient (surrounding)
environment. Because of this relationship, the integumentary system has a number of
functions related to the environment and the individual's reactions to the environment.
3-16. REDUCTION OF FRICTION AND ITS EFFECTS
Over time, the body is likely to rub against many varied objects. The resulting
frictional forces would be expected to damage the body surface. For comparison,
consider the outer surfaces of older automobiles and other man-made objects.
a. Hairs. Hairs minimize friction by allowing surfaces to slip or slide over each
other.
b. Outer Dead Cells. Where there is no hair (glabrous condition), the outer
dead squamous cells rub off to reduce frictional forces. Within a couple of weeks after
they arrive at the surface, the outer dead cells are removed during the activities of daily
life.
c. Thickening of the Integument. The dermis and epidermis tend to become
thicker whenever they are subjected to forces of pressures greater than average.
Callouses are an extreme example of this.
3-17. WATERPROOFING
The outer layers of dead horny cells are kept flexible by oil from the sebaceous
glands. Thus, these layers form an essentially waterproof covering for the body. This is
very important in preventing general dehydration of the body. Dehydration (water loss)
is a very important problem in burn patients who have lost a full thickness of the
integument.
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