Structure And Functions Of Skin
Skin is the largest organ of the human body. It is an impressive and vital organ. It is a fleshy surface with hair, nerves, glands and nails. It consists of hair follicles which anchor hair strands into the skin.
It acts as a barrier between outside and inside environment.
The skin has different thicknesses and textures. E.g. the skin under the eyes is as thin as paper but is thick at the soles of the feet and palm.
The skin acquires an area of 20 square feet on our body surface.
It protects us from external elements, regulates the body temperature by releasing water in the form of sweat, and allows sensations such as touch, heat, and cold. It also guards the bones, muscles and other vital organs of our body.
Structure Of Skin
It provides a protective covering throughout our body and acts as the body’s initial barrier against external harmful substances or foreign particles. The hair is made up of a protein called keratin, and the same protein is found in hooves, horns, claws and nails of other animals too.
The structure of the skin is made up of three layers of, namely:
Epidermis Dermis Hypodermis
r> Epidermis
It is the outermost layer of the skin. The cells in this layer are called keratinocytes. The keratinocytes are composed of a protein called keratin. Keratin strengthens the skin and makes it waterproof.
Melanocytes that produce melanin are also present in this layer. In addition, Merkel cells essential for light-touch sensation and
The epidermis is subdivided into the following layers: Stratum corneum
Granular cell layer Spinous cell layer Basal cell layer
Basal Layer
is beneath all other layers of the epidermis, where new cells are produced continuously. As a result, cells get an upward thrust by the continuous formation of new cells. They grow actively because of the blood supply below this layer due to the presence of blood vessels.
Spinous and Granular layer
As these cells approach the next layer, they vary in their shapes and sizes. These irregularities give rise to the next layer, the spinous layer, above which the cells proceed to the granular layer. Cells hence begin to shrivel and die as a result of being far away from the blood supply. This results in the formation of a protein called Keratin.
Stratum Corneum The outermost layer of the epidermis is the
uniform scale-like cells which are overlapped. These cells contain abundant keratin and provide rigidity to the skin. These cells are regularly peeled off the skin’s surface which is balanced by the cells of the basal layer.
Dermis
Beneath the epidermis is the dermis layer. It consists of papillae which form finger-like projections. This layer constitutes of fat, fibres and collagen which makes the skin flexible and strong. Dermis synthesizes Vitamin D to absorb calcium on exposure to sunlight.
It consists of blood vessels which supply blood for the formation of new cells. They are also vital in regulating body temperature. Nerves in the dermis are sensitive to environmental factors such as pressure and temperature. Also, it contains the hair follicles and sebaceous oil gland which produces sebum.
It acts as a lubricant and protects the skin by acting against the microbes. Sweat glands are produced all over the skin and release sweat through specialized ducts. They help the body to
An arrector pili muscle is attached to each hair follicle. This helps in the erection of hair when we experience cold or strong emotions.
Hypodermis
This subcutaneous layer is made up of fat and forms the innermost layer. Its thickness is dependant on the region where they appear and vary. For example, the area around the eye is comparatively thinner for the easy movement of the eye.
Fat stored provides energy and is crucial in reacting to ambient temperature. It insulates the body from heat and cold. It cushions the internal organs, muscles and bones, and protects them from any injuries
Function Of Skin
Protection from the Environment
This is foremost and the most important function of the skin. It keeps the pathogens away so that they do not enter into the skin and Cause any harm.