By: Sasha Caldwell
The Integumentary System has multiple important roles in maintaining life. It includes protection, temperature regulation, sensory reception, biochemical synthesis, and absorption. All body systems work in an interconnected manner to maintain the internal conditions essential to the function of the human body. The Integumentary System contains the largest organ in the human body, the skin. The skin cushions and protects the delicate organs beneath it and it also changes the temperature of the body to maintain stable conditions for proper functioning of the other organs in the body. It also involves the hair and fingernails.
I find the skin very important and interesting. The skin has a major importance to maintaining life. The skin is also known as your birthday suit. It is the largest organ of the human body, it is 12-15% of the body weight. Skin also provides the body a physical barrier to keep out foreign materials and to prevent the body from drying out. The total surface area of the human skin is approximately 20 sq. feet. A completely new layer of skin is produced by a human every month. The thickness of the skin varies from ½ to 6 mm depending on the area of your body. The thinnest area of skin on the human body is the eyelids. There are 7 layers of flat stacked cells. The number of dead skin cells that fall off the body every minute are between 40,000 to 60,000. The average humans body skin that is lost in a lifetime is equal to 40 pounds of weight. Skin cells synthesize melanin which gives our skin its color. When the skin is exposed to UV lights it makes vitamin D. The sensory fibers which end in the skin monitor the external enviroment. These nerve fibers respond to touch, pain, pressure, temperature, etc. Heat and cold receptors are located in the skin. When the body temperature rises, the hypothalamus sends a nerve signal to the sweat-producing skin glands, also known as the sweat glands, causing them to release about 1-2 liters of water per hour, cooling the body down. Water loss occurs in the skin by two ways: evaporation and sweating, in hot weather up to 4 liters of water per hour could be lost by these mechanisms. When the body temperature falls, the sweat glands constrict and sweat production decreases. There are over 2 million sweat glands on the surface of the human body. Toxic waste is excreted through perspiration or sweating. In one square inch of skin there are: 4 yards of nerve fibers, 1300 nerve cells, 100 sweat glands, 3 million cells, and 3 yards of blood vessels. The skin consists of 3 different layers, the epidermis, dermis, and