Parts of the Integumentary System
Function
The parts of the integumentary system act together as a barrier in three ways: a chemical barrier, a physical barrier and a biological barrier. The parts of the integumentary system act in cooperation with the immune system to form a biological barrier. Specialized cells in the skin detect and destroy foreign bacteria. Some skin cells also present antigens to immune cells that can then destroy the foreign cell.
The integumentary system acts as a physical barrier due to hard, keratinized cells in the skin, nails and hair. These relatively hard cells are not completely impenetrable but protect the internal organs and blood system from the daily onslaught of the external environment. Other cells in the skin produce water repellant substances that keep the body from absorbing or loosing too much water or water-soluble chemicals, like salt. Hair is important in sensing insects crawling on the skin, guarding against physical trauma to the scalp, filtering foreign particles and regulating heat.
The integumentary system acts as a chemical barrier in large part because of the skin. The skin has appendages such as sweat, or suderiferous glands and oil, or sebaceous glands. These glands secrete substances onto the skin that deter the reproduction of bacteria. The skin is naturally host to innumerable bacteria. This is considered normal flora, or biota, and is useful to the body. The presence of biota reduces colonization of foreign bacteria that may invade and harm the body. However, it is also important to maintain appropriate levels of the biota. Skin secretions have a natural antibiotic component and help maintain a low pH that retards bacterial growth. Finally, the skin produces a pigment called melanin. Melanin acts as a chemical barrier to ultraviolet rays from the sun. Melanin protects the DNA in lower tissues from mutation and destruction.
Imbalances
Imbalances in the parts of the integumentary system can be caused by burns, cancer and foreign substances. Some lipid-soluble substances can pass through the water repellent chemicals in the skin and enter into the lower tissues. Examples of lipid-soluble toxins include: lead, mercury, acetone, paint thinner, steroids and oleoresins--the oils from poison ivy and poison oak. These can lead to destruction of tissues or damage to internal organ systems.
Burns destroy the physical barrier capacities of the integumentary system. Burns leave the body susceptible to fluid and electrolyte loss and bacterial infection. Both of these results are potentially life-threatening.
Integumentary cancers are uncharacteristic growths of skin cells. Different skin cells have different rates of malignancy and metastasis, or growth that proliferates to other parts of the body. Melanocytes, the cells responsible for melanin production, are highly metastatic and do not respond well to chemotherapy. They also account for the lowest number of skin cancers.
Tags: integumentary system, cells skin, chemical barrier, physical barrier, skin cells, acts chemical, acts chemical barrier
