An organ system of the body which covers the body and provides protection from damage is known as the integumentary system. Along with the skin, this system is formed of scales, hair, nails, and feathers in case of birds.
The integumentary system is divided into three parts, i.e., the epidermis, dermis, and subdermis. The main function of this system is to provide a protective layer to the organ. This system makes up for more than 10% of the total body weight of the human body.
Facts about the Integumentary SystemThe following facts about this system would help us gain a deeper insight about this largest organ system of the body.
- The epidermis, which is the uppermost layer of the integumentary system, is formed of epithelial cells. The squamous epithelium, which is the keratinized and stratified part of the epidermis, consists of 4 different types of epithelial cells, viz., melanocytes, keratinocytes, Langerhans cells, and Merkel cells.
- The sweat glands present in the integumentary system are called apocrine and eccrine. The liquids secreted by the eccrine glands not only help in regulating the body temperature, but also in the elimination of waste products from the body.
- The total surface area of the human skin is approximately 20 sq. feet.
- The dark color of the skin is due to the chemical known as melanin which is produced by melanocytes.
- The Langerhans' cells are important from the point of fighting against foreign bodies. These cells in collaboration with other cells strengthen the immune system of the body.
- The nutrition of the epidermal cells does not come from direct blood supply. The dermis layer provides the required amount of nourishment to the epidermis.
- The dermis layer, which is present beneath the epidermis, is formed of collagen, elastic fibers, and reticular fibers. The dermis is composed of two layers, i.e., the reticular and papillary layers. The former one contains dense connective tissues, while the latter has loose connective tissues.
- An important part of the integumentary system, hair is composed of medulla, cuticle, and the cortex. Cuticle is the outermost, while cortex is the innermost layer. Both these layers are formed from the same material, i.e., hard keratin. The medulla is, however, composed of air and soft keratin.
- The nails which are translucent in appearance, develop into hard plates. Nails are composed of keratin and their structural components include the body, lunula, free edge, and root.
- The five layers of the epidermis are stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. Stratum corneum is the layer of the epidermis which occurs in soles and palms.
- The number of dead cells which fall off the body every minute are between 50,000 - 60,000.
- Body skin equal to the weight of 40 pounds is shed by a human body during its lifetime.
- A completely new layer of skin is produced by a human being in a single month.
FunctionsThe main function of the integumentary system is to protect the internal organs from any kind of damage. Apart from that, the regulation of body temperature, preventing pathogens from entering the body, perspiration, generation of vitamin D, and protection from UV rays are some of the other functions of the integumentary system. Protection of the body from dehydration is also one of the important functions. Moreover, the storage of fats, water, vitamin D, and glucose takes place in the skin.
The above facts, thus, indicate that the integumentary system is one of the most important organ systems of the body. The functions and facts provide information about the different components in short.