Functions of the Integumentary System
Integumentary system functions vary from organ to organ and from tissue to tissue. We will look at each organ and describe the functions of each as well as why they are important:
1. Skin: The skin is the largest organ in the human body. It is composed of three layers: the epidermis, the dermis and the subdermis.
Epidermis: Blood vessels are absent in the outermost layer, the epidermis. Squamous epithelial cells make up the majority of the epidermis. These cells include keratinocytes, melanocytes and even Langerhans cells. The epidermis is further subdivided into the corneum, lucidum, granulosum, spinosum and basale.
The various strata have their own functions as do the cells that make up the epidermis. These include protecting the body from foreign pathogens, waterproofing the body, skin pigmentation and fighting off foreign bodies as part of the immune system. They are also responsible for sensations of touch. The importance of the functions of the epidermis is quite obvious. Infections can cause a variety of diseases, so protection from foreign agents and pathogens is necessary.
Similarly waterproofing the body allows keeping liquids from penetrating the skin. Skin color or the pigment in the skin is important to protect us from ultraviolet radiation. Sensations of touch, part of the somatosensory system, are important to the survival of the individual.
Dermis: The dermis is the next layer beneath the epidermis. This layer contains many important glands. Sweat glands responsible for excretion of waste products and perspiration are located in this layer. Papillary ridges, located in the dermis, give us our unique fingerprints. Collagen fibers make up the connective tissue found in the dermis giving the skin elasticity. These functions are important to the survival of a human being.
Sweat glands help to get rid of waste and are responsible for cooling down the body, thus maintaining thermal regulation. Fingerprints provide a unique signature for a human being. Skin elasticity allows the skin to stretch, which is useful in many situations, and also gives the skin strength so as to avoid getting wrinkles which can make the skin appear to sag and unattractive.
Subcutaneous: The final layer of the skin is the subcutaneous. It is composed of adipose tissue. These provide cushioning of the organs that lie underneath the skin and also regulate the body temperature. These are essential functions as organs need to be protected for survival and body temperature needs to be regulated for the purpose of maintaining a stable internal environment for the functioning of the body.
2. Hair: As part of the integumentary system, hair comes in three different types in the human body. One is lanugo hair that covers the entire body of the fetus. Another is vellus hair which grows on most parts of the human body. Men have less vellus hair when compared to women and children.
Terminal hair is the third type of hair found in the axillary, male beard and pubic regions. Hair roots and hair bulbs are responsible for the extension of the hair to the surface. The hair shaft is the superficial layer of the dermis. The hair root is also found in the dermis. The hair follicle surrounds the hair root.
Hair is responsible for protection. Oil glands in the hair follicles keep the hair moist. Thermal regulation is also maintained to a certain extent by the hair. These functions are important as the vital organs need protection for survival and temperature regulation is required for a stable internal environment. The hair also plays a vital role in the appearance of a human being, thus helping in the process of selecting the best mate.