Physiology of Skin

The skin comprises three layers: epidermis, dermis and the hypodermis. Skin forms the major link between man and the environment. The skin is the Human body’s LARGEST ORGAN, covering an area of about 2 square meters or 22 square feet and weighs around 3.6 kilogram. It is the thickest on palms and soles of feet measuring about 1.5 mm thick and the thinnest on the eyelids and post auricular region measuring 0.05 mm thick. It consists of various layers and tissues each with important functions.

In addition to these main layers, the skin also contains various structures that are important for its functioning, including hair follicles, sweat glands, oil glands, and blood vessels. The skin also contains nerve endings that allow us to feel sensations such as touch, pressure, temperature, and pain. The anatomy and function of these structures are essential for the proper functioning of the skin.

skin physiology

Functions of Skin

The skin performs several important functions, including:

  1. Protection:

    The skin acts as a barrier, protecting the body from physical, chemical, and biological damage, such as cuts, bruises, and infections.

  2. Regulation of body temperature:

    The skin helps to regulate the body temperature through sweating, which cools the body, and through blood flow to the skin, which helps to warm the body.

  3. Sensation:

    The skin contains nerve endings that allow us to feel sensations such as touch, pressure, temperature, and pain.

  4. Vitamin D synthesis:

    The skin contains cells called keratinocytes that can convert ultraviolet light from the sun into vitamin D, which is important for bone health.

  5. Immune defense:

    The skin is a component of the immune system and contains immune cells that can detect and respond to harmful pathogens.

  6. Excretion:

    The skin is also involved in the elimination of waste products, such as sweat, which contains salt, urea, and other substances.

  7. Hydration:

    The skin helps to retain moisture, keeping the body hydrated and preventing dehydration.

  8. Synthesis of melanin:

    The skin produces melanin, a pigment that helps to protect the skin from the harmful effects of ultraviolet (UV) radiation from the sun.


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