(a) Characteristics. The second layer of skin, the dermis or corium, is
sometimes called the true skin. This layer holds the epidermis in place by connective
tissue and elastic fiber. The dermis is very thick on the palms of the hands and the
soles of the feet but very thin on the eyelids, penis, and scrotum. The dermis contains
the following: numerous blood vessels, nerves, lymph vessels, hair follicles, sweat
glands, and sensory receptors.
(b) Papillary layer. This upper one-fifth of the dermis has small, finger-
like projections called dermal papillae. These projections reach into the concavities
between ridges in the deep surface of the epidermis. This region or layer consists of
loose connective tissue containing fine, elastic fibers.
(c) Reticular layer. This layer makes up the rest of the dermis. The
reticular layer consists of dense, irregularly arranged connective tissue that has
interlacing bundles of collagenous and coarse fibers. Between the fibers are adipose
(fat) tissue, hair follicles, nerves, oil glands, and the ducts of sweat glands. The
collagenous and elastic fibers together give the skin strength, extensibility, and
elasticity. The skin stretches during pregnancy, obesity, or edema. Elasticity allows the
skin to contract after such stretching. If the skin has been stretched severely, small
tears may occur. Initially, the tears are red; they lose the redness but remain visible as
silvery white streaks called striae.
Extensibility is the ability to stretch. Elasticity is the ability to return to original
shape after extension or contraction.
(3) Subcutaneous-adipose. This layer is composed of loose connective
tissue combined with adipose (fatty) tissue. The subcutaneous layer of skin has several
(a) Storehouse for water and particularly for fat. Much of the fat in an
overweight person is in this layer.
(b) Layer of insulation protecting the body from heat loss.
(c) Pads the body giving the body form and shape and cushioning and
protecting the body from blows.
(d) Provides a pathway for nerves and blood vessels.