Organisms are composed of atoms that form molecules that form macromolecules (Shier, Butler, & Lewis, 2009). These molecules come together and form organelles that structure the cell and tissues (p.3). Tissues form organs, and organs working together form the organ system (p3). These organ systems constitute the organism (p3). Each organ system has an important function in the body. These systems all work together to maintain and support the conditions that cells, tissues and organs need to function properly. There is one system that is not as well known as the others; it is the intergumentary system. Most people know about the organs of the intergumentary system, but do not know that these organs work together to form this system. The intergumentary system is composed of the skin and related structures, which include hair, nails, sensory receptors, and glands (Shier, Butler, & Lewis, 2009). This system has an important function as it provides protection to the body, helps maintain body temperature, and contains sensory receptors (p.117). The skin, which is the largest organ of the body and an organ of the intergumentary system, has essential functions such as regulating homeostasis and body temperature, also delaying the loss of water from deeper tissues, storing sensory receptors, synthesizing elements biomechanical and discharging waste from the body. body (p.117). The skin has two layers: the epidermis (outer layer) and the dermis (inner layer) (p.117). There is also a subcutaneous layer or hypodermis (Shier, Butler, & Lewis, 2009). According to Shier, Butler and Lewis 2009 “as the name indicates, this layer is under the skin and not a true skin layer”. This layer contains the blood vessels that sit in the center of the paper, and these glands help balance body temperature (p.124). The fluid secreted by these eccrine glands is transported outside the body via a tube that has an outward opening like a pore (p.124). Another sweat gland is the apocrine gland which is activated during puberty. According to Shier, Butler and Lewis (2009) “these glands secrete according to the same mechanism as eccrine glands, usually when a person is emotionally upset, frightened, in pain or during sexual arousal”. Other sweat glands are the serous glands that secrete, and the female mammary glands that secrete milk (p.124). Nails which are another accessory of the skin cover and protect the ends of the fingers and toes (Shier, Butler, & Lewis, 2009). Nails have a lunula which is the growth area of ​​the nail (p.122). This means that if the lunula is damaged the nail probably will not grow back.