The skin (cutis) is the largest organ of the common integument of vertebrates.
The general surface of the skin in humans
is 1.5–2 m² and the thickness is 0.5–5 mm.
The skin consists of three layers:
epidermis,
dermis
and subcutaneous tissue.
The epidermis (epidermis) is the outer layer with a protective and reproductive function, which contains a pigment- melanin and creates several layers:
basal (stratum basale),
spiny (stratum spinosum),
granular (stratum granulosum),
bright (stratum lucidum)
and cornea (stratum corneum),
which include:
compact layer (stratum compactum)
and the keratinising layer (stratum disjunctum).
Dermis (cutis vera), the middle layer, is composed mainly of fibrous connective tissue, it contains receptors, blood vessels, nerves, glands and hair roots, it is a nourishing and supporting layer (1 to 3 mm thick).
There are two basic layers of the dermis:
papillary layer and reticular layer.
The dermis contains collagen, elastin and reticulin fibers as well as cellular elements: fibroblasts, mast cells and blood cells, as well as vessels and nerves.
Skin functions
isolation of the internal environment from the external one- against infection with bacteria, fungi and viruses.
protects against mechanical, thermal, chemical factors and light radiation.
ensures constant conditions for the body’s internal environment (homeostasis).
performs the perceptual function of heat- cold, pain, touch, and expressive function in expressing emotional states.
resorption- absorption,
takes part in the storage and metabolism of matter.
Skin types
DRY
(rough, matte, not very flexible, dry skin and discomfort occur).
NORMAL
(no defects or skin problems, it is smooth, properly moisturised, has a uniform color).
MIXED
(combines the features of dry and oily skin).
OILY
(there is overproduction of sebum in the T zone (forehead, nose and chin), eruptions and inflammation appear, shine and enlarged pores).
Skin subtypes
DEHYDRATED
WITH ACNE
WITH DISCOLORATIONS
WITH CAPILLARS
MATURE
SENSITIVE- OVERREACTIVE
ALLERGIC
Skin, epidermis, dermis. Skin structure. Structure of the epidermis, layers of the epidermis. Skin functions. Skin types. Skin subtypes.