Did you know that your skin weighs about 8 pounds and it covers an area of about 22 square feet, well it would if it weren't on your body, but your skin although it may not seem that impressive plays an important role in your ability to live.
Your skin is a part of the often forgotten Integumentary system or the excretory system. It is the job of the Integumentary system to protect the deeper tissue from outside damage. Whether it is mechanical damage, bumps and bruises, or chemical damage, which comes from contact with acids or bases, the structure of skin can protect us from these hazards. This protection is achieved by a combination nerves and proteins located in the skin. Your skin also excretes some of the bodies waste products through sweat. |
Your skin is comprised of three layers; the epidermis, dermis, and hypodermis. Each layer has unique properties that when combined protect the body from the harmful things in our atmosphere.
The dermisThe Dermis is a strong stretchy layer that helps bind the body together. the dense layers of the dermis consist of two major layers; the papillary layer and the reticular layer. The dermis contains phagocytes that act to prevent bacteria, that have penetrated the dermis, from entering the body further. Additionally, the dermis contains many nerve endings that send messages to the central nervous system when stimulated by the environment (this will be explored further in the section on the nervous system).
The papillary layer or upper dermal region has uneven surface which juts out into the above epidermal region. each of these juts, or papillae, contain capillary loops that provide nutrients to the epidermis above. The reticular layer is the deepest skin layer. This layer contains irregularly arranged connective tissue fibers, blood vessels, sweat and oil glands. This layer also has deep pressure receptors called lamellar corpuscles. |
The EpidermisThe Epidermis is comprised of 5 layers or strata, these layers are the stratum basale, spinosum, granulosum, lucidum (this is only found in thick skin ex. hands and feet), and corneum.
Did you know that the epidermis has no blood flow of its own that's why it is possible for people to shave their hair without bleeding even though many cell layers have been lost. Most epidermis cells are kertinocytes (keratin cells) which means they produce keratin, the fibrous protein that makes the epidermis a tough protective layer. The HypodermisThe hypodermis is the deepest layer of skin and consists mostly of fatty tissue.
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