A recent study by scientists at the National Jewish Medical & Research Center and the University of Colorado Health Sciences Center have discovered that skin cells ward off infection with a protein called human β-defensin-3. This study helps explain why infection of healthy skin cells rarely occurs, even though they are constantly exposed to bacteria. One more reason to be amazed by this amazing organ--skin.
The skin/integument system is the largest organ in the body. It is a tough, resilient barrier that covers the body. It is composed of an outer epidermis, an underlying dermis layer, and the subcutaneous fat layer. The structure of the skin varies considerably from one area of the body to another. The scalp is much thicker than the eyelid skin. The scalp has much more hair (for most of us) than our forearms. Our palms and soles have no hair. The axillary skin has many more sweat glands than the abdominal skin. The skin is commonly affected in systemic diseases. It is also the location of many diseases limited to the skin. It is often damaged by external stimuli such as fire, sunlight, chemicals, allergens, and infectious agents. The skin serves critical functions: Protection• Thermoregulation• Immunologic Response• Barrier to water loss• Secretion of Wastes• Sensory
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