Derma

Derma is the technical term for the skin, the largest organ of the human body. It serves as the first line of defense against external threats, and plays a crucial role in temperature regulation, sensation, and synthesis of vitamin D.

Structure

The derma, or skin, is composed of three main layers: the epidermis, the dermis, and the hypodermis.

Epidermis

The epidermis is the outermost layer of the skin. It is composed primarily of keratinocytes, which produce the protein keratin, a key component of the skin's protective function.

Dermis

The dermis is the middle layer of the skin. It contains collagen and elastin, proteins that provide the skin with its strength and elasticity. The dermis also contains blood vessels, lymph vessels, hair follicles, and sweat glands.

Hypodermis

The hypodermis is the deepest layer of the skin. It is primarily composed of adipose tissue, which provides insulation and cushioning for the body.

Functions

The derma performs several key functions, including:

• Protection: The skin serves as a barrier against physical, chemical, and biological threats.
• Regulation: The skin helps to regulate body temperature through sweating and vasoconstriction or vasodilation of blood vessels.
• Sensation: The skin contains numerous nerve endings that respond to touch, pressure, temperature, and pain.
• Synthesis: The skin synthesizes vitamin D when exposed to sunlight.

Diseases

There are many diseases that can affect the derma, including dermatitis, psoriasis, eczema, and skin cancer. These diseases can cause symptoms such as redness, itching, and scaling.

See also

• Dermatology
• Skin care
• Skin disease