Skin and Integumentary System

The skin is the largest organ in the body: 12-15% of body weight, with a surface area of 1-2 meters. Skin is continuous with, but structurally distinct from mucous membranes that line the mouth, anus, urethra, and vagina. Two distinct layers occur in the skin: the dermis and epidermis. The basic cell type of the epidermis is the keratinocyte, which contain keratin, a fibrous protein. Basal cells are the innermost layer of the epidermis. Melanocytes produce the pigment melanin, and are also in the inner layer of the epidermis. The dermis is a connective tissue layer under the epidermis, and contains nerve endings, sensory receptors, capillaries, and elastic fibers.
Disorders

• Acne (chronic inflammatory disorder of the skin, usually related to changes during puberty and overactive sebaceous glands.)
• Asteatosis ( A dry, scaly condition, due to a deficiency of sebum, due to aging or body disorders. )
• Skin Cancer ( A disease that is brought on by the sun.)
• Birthmark ( A vascular tumor of the skin and subcutaneous tissues, visible at birth or soon after.)
• Athletes Foot Disease ( common fungal infection of the feet)
• Comedones (Black Heads)-(Wormlike mass of keratinized cells/sebum blocking the pores. )
• Mole (A sleshy skin tumor that usually is pigmented: colors range from brown to black)