what is meant by epidermis
Answers
Medical Definition of Epidermis
Epidermis: The upper or outer layer of the two main layers of cells that make up the skin. The epidermis is mostly made up of flat, scale-like cells called squamous cells. Under the squamous cells are round cells called basal cells. The deepest part of the epidermis also contains melanocytes. These cells produce melanin, which gives the skin its color.
The other main layer of the skin is the dermis, the inner layer of skin, that contains blood and lymph vessels, hair follicles, and glands. These glands produce sweat, which helps regulate body temperature, and sebum, an oily substance that helps keep the skin from drying out. Sweat and sebum reach the skin's surface through tiny openings called pores.
The key symptom of dry skin is itching. People who have dry skin can often find rough, dry, red patches on their skin, and these patches are often itchy. Typical skin areas affected include arms, hands, lower legs, abdomen, and areas of friction such as ankles and soles. As skin dryness becomes more severe, cracks and fissures may evolve.
Symptoms and signs:
Itching
Rough dry skin
Red plaques of eczematous skin (nummular eczema)
The itchy feeling may worsen the severity of dry skin. Itching can lead to the development of the "itch-scratch" cycle. That is, as a person feels itchy, he or she scratches in response, which exacerbates the itch, and so on. The itch-scratch cycle is often seen when conscious control of scratching is low or absent, for instance during sleep.
Most common dry skin areas are
the lower legs,
hands,
arms.
Constantly scratching and rubbing the skin may cause the skin to become thick and leathery. For others, small, red, raised bumps may appear on their skin, and these bumpy spots can be irritated, opened, and infected if scratched.