Grade 10 Science: Skin

Human skin is the outer cover of the human body and it can be regarded as the largest organ in it. The skin is a protective layer that has multiple roles. The skin has two major layers namely, the Epidermis and the Dermis. The epidermis is the outermost layer of the skin that provides protection. This is the layer that is visible to the eyes and it protects the body from the harmful Ultra violet rays of the sun by producing a pigment called melanin. Melanin causes the color or the tone of our skin. It is the epidermis that repairs the dead cells with new cells. The dermis is located underneath the epidermis and it consists of sweat glands, hair, sebaceous glands (oil glands), muscles, blood capillaries and nerve endings. This layer has more thickness than the epidermis. The dermis also supports the structure of the skin. The layer that lies beneath the dermis is the hypodermis or subcutis that connects the skin to bones and muscles. Hypodermis is made of fat and helps to keep the body warm.

The skin protects the body in several ways. The epidermis of the skin has several layers that help to reduce the loss of water from the body. Melanin which is a pigment that is produced in the epidermis helps to safeguard the body from the harmful ultra violet rays of the sun. The sebaceous or oil glands protect the skin against infections that can be caused by microbial activity when the skin is exposed. The body temperature is controlled by the skin and this is done by controlling the blood flow and the secretion of sweat. When the temperature of the external environment rises, sweat is secreted by the sweat glands. This is done to release the body heat and to cool off the body. On the other hand, when the external temperature is low, it prevents the blood supply to the skin surface by narrowing the blood vessels and reduces the secretion of sweat. That is why we do not sweat when it is cold outside. The skin also acts as the primary organ for the sense of touch in the body. Nerve endings that can detect or are sensitive to touch, pressure and temperature are found on the dermis of the skin. The skin consists of thousands of these receptor cells or sensors. The epidermis of the skin synthesizes vitamin D, in the skin cells when the skin is exposed to the ultra violet rays of the skin. This gives immunity to the body and helps to maintain healthy bones. Skin is an excretory organ where the excretory products such as urea, uric acid, eater and ammonium salts are excreted from the body as sweat from the sweat glands on the skin.

It should be noted that skin must be given the right care and protection so that it will be able to perform the above functions efficiently. A nutritious diet with fresh fruits and vegetables that are rich in Vitamin A and E helps to maintain a healthy skin. Moreover, we should drink plenty of clean water regularly and it provides the required moisture to the skin. The skin should be cleaned gently by bathing daily while using mild products that do not harm the skin. It is advised to avoid exposing the skin to direct sunlight for a long period of time. Also it is essential to refrain from smoking or being around smokers as it makes the blood vessels narrow where the skin does not get the required oxygen and nutrients. This may result in wrinkles where the skin loses its elasticity and strength. Furthermore, proper stress management, using cotton clothes, refraining from exchanging clothes with others will also help in maintain a healthy skin that is free of diseases. Medical advice should be sought and proper treatments must be done if the skin develops infections or disorders such as warts, acne / pimples, dry heels, removal of skin, pityriasis and eczema. These can be due to the lack of sufficient nutrients and microbial activity.

 

 

 

 

 

 

 

by Mekhala Egodawele

Photo source : Internet