Cutis (anatomy)

Cutis or skin is the outermost layer of the human body, serving as a protective barrier against environmental hazards. It is a complex system composed of several layers, each with specific functions and structures.

Structure

The skin is composed of three primary layers: the epidermis, the dermis, and the hypodermis (also known as subcutaneous tissue).

Epidermis

The epidermis is the outermost layer of the skin, providing a waterproof barrier and creating our skin tone. It is composed mainly of keratinocytes, which produce the protein keratin, a key structural material in the skin, hair, and nails.

Dermis

The dermis lies beneath the epidermis and contains tough connective tissue, hair follicles, and sweat glands. It is responsible for the skin's elasticity and strength. The dermis also houses the nerve endings that provide the sense of touch and heat.

Hypodermis

The hypodermis is the deepest layer of the skin, composed of fat and connective tissues. It helps insulate the body from heat and cold, provides protective padding, and serves as an energy storage area.

Functions

The skin has multiple functions, including:

• Protection: It acts as a barrier against physical injuries, chemicals, and harmful microorganisms.
• Regulation: It helps regulate body temperature through sweat and hair, and changes in peripheral circulation and fluid balance.
• Sensation: It contains a variety of nerve endings that react to heat, cold, touch, pressure, vibration, and tissue injury.
• Immunity: It plays a crucial role in the immune system, protecting the body against pathogens and excessive water loss.
• Production of Vitamin D: It produces Vitamin D in response to exposure to sunlight.

Diseases and Disorders

There are many diseases and disorders that can affect the skin, including dermatitis, psoriasis, eczema, acne, skin cancer, and rosacea. These conditions can cause a variety of symptoms, including redness, itching, peeling, dryness, blisters, and sores.

See Also

• Integumentary system
• Human skin color
• Skin care