The Integumentary System

The Integumentary System

The Integumentary System is the largest organ in the body consisting of skin, nails, hair, and exocrine glands. The skin forms a barrier to protect the body from UV light, chemicals, disease, and physical damage. The Integumentary System is the first line of defense against bacteria, viruses, and other microbes. The skin is a sensory organ which has receptors that detect heat and cold, touch, pressure and pain. The Integument has three layers; the Epidermis, Dermis, And the Hypodermis. The Epidermis is the outermost layer of the skin composed of stratified squamous cells. The Epidermis contains 5 layers; stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum starting from the bottom up, the stratum basale is made up of keratinocytes and melanocytes. The keratinocytes are what make protein to give off to the cells and make the cells hard. Melanocytes are what make melanin and protect the skin from overexposure of sunlight. The stratum spinosum is the layer that the cells look kind of spiny, its main function is to protect against foreign materials and to produce and retain lipids that prevent moisture loss from the skin. The stratum granulosum is the layer where keratin proteins and water-proofing lipids are being produced and organized. The stratum lucidum is the layer of dead skin cells it's function is to help the body handle friction, that is why it is mostly located where you have thick skin such as the soles of your feet and the palms of your hand. Last but not least the stratum corneum is made up of dead layers that keep bacteria out and keeps in body fluid.

Layers of the skin.

The Integumentary System helps maintain homeostasis because it helps assist in the regulation of body temperature, water balance, protection, sensory reception, biochemical synthesis, and absorption. An example of homeostasis would be when you get cold, your body has to warm itself up to the regular temperature the body is used to being at through and vasoconstriction. When your body is too cold it uses vasoconstriction to keep your body warm and from freezing, it contracts your muscles to produce heat for your body. The muscle arrector pili is what causes goose bumps.When these muscles contract, they make the hair follicles to stand on their ends thus leading to goose bumps. This process is important for insulation of the body and heat retention.



function of the arrector pili


Resources:


 http://www.innerbody.com/anatomy/integumentary
http://www.ask.com/question/what-is-the-function-of-the-arrector-pili-muscle
http://sciencenetlinks.com/student-teacher-sheets/integumentary-system/