Integumentary System Study Documents

Integument The skin and its accessory structures, including hair, nails, and glands, that protect the body from external factors, regulate body temperature, and provide sensory information Skin The largest organ of the body, consisting of two main layers: the epidermis and the dermis. It provides protection, excretion, temperature control, production of melanin, production of keratin, synthesis of vitamin D, storage of lipids, and coordination of immune response Epidermis The outermost layer of the skin, composed of stratified squamous epithelium. It acts as a barrier against pathogens, UV radiation, and water loss Dermis The layer of connective tissue, nerve, and muscle beneath the epidermis. It contains blood vessels, hair follicles, sweat glands, and sensory receptors Adipose tissue A layer of fat tissue located below the skin. It provides insulation, cushioning, and energy storage Areolar tissue A layer of loose connective tissue located below the skin. It supports and connects the skin to underlying structures Keratinocytes Cells in the epidermis that produce keratin, a tough protein that gives the skin its strength and waterproof properties. They also produce lamellar granules, which help to form the skin's barrier Melanocytes Cells in the epidermis that produce melanin, a pigment responsible for skin color and protection against UV radiation Macrophages in the epidermis that play a role in the immune response by captur1/4 Langerhans cells ing and presenting antigens to immune cells Merkel cells Tactile epithelial cells in the epidermis that function as touch receptors, providing sensory information about light touch and pressure Stratum corneum The outermost layer of the epidermis, composed of dead keratinocytes. It acts as a protective barrier against water loss, pathogens, and mechanical stress Stratum lucidum A translucent layer of the epidermis found in thick skin, composed of dead keratinocytes. It provides additional protection and thickness to the skin Stratum granulosum A layer of the epidermis composed of keratinocytes with lamellar granules. It plays a role in the formation of the skin's barrier and the production of lipids Stratum spinosum A layer of the epidermis composed of keratinocytes, Langerhans cells, and Merkel cells. It provides structural support and participates in immune responses Stratum basale The deepest layer of the epidermis composed of actively dividing keratinocytes, melanocytes, and Merkel cells. It is responsible for the continuous renewal of the epidermis Thin skin Skin that covers most of the body, with a thin epidermis. It lacks the stratum lucidum, epidermal ridges, and has fewer sweat glands and sensory receptors compared to thick skin Thick skin Skin found on the palms and soles, with a thick epidermis. It has a distinct stra2/4 tum lucidum, thick stratum corneum, and lacks hair follicles and sebaceous glands Papillary layer The superficial layer of the dermis composed of areolar tissue. It contains dermal papillae, blood capillaries, and corpuscles of touch, providing nourishment and sensory information to the epidermis Reticular layer The deeper layer of the dermis composed of dense irregular connective tissue. It contains collagen and elastic fibers, adipose cells, hair follicles, nerves, oil glands, and sweat glands, providing strength, elasticity, and support to the skin Skin cancer The abnormal growth of skin cells, including nonmelanoma types (basal cell carcinoma and squamous cell carcinoma) and melanoma. It is often caused by exposure to UV radiation and can be life-threatening if not detected and treated early Psoriasis A common and chronic skin disorder characterized by the rapid division and movement of keratinocytes from the stratum basale to the stratum corneum. It results in the formation of thick, red, and scaly patches on the skin Burns Injuries to the skin caused by heat, chemicals, electricity, or radiation. They are classified into four degrees: first-degree, second-degree, third-degree, and fourth-degree burns, depending on the severity and depth of tissue damage Pressure ulcers Skin injuries caused by constant pressure or friction, resulting in the shedding of epithelium due to a deficiency of blood flow to tissues. They commonly occur in 3/4 bedridden patients and can lead to serious complications if not properly managed Acne A common skin condition characterized by inflammation of the sebaceous glands, which become infected with bacteria. It often results in the formation of pimples, blackheads, and whiteheads Hair A filamentous structure that covers the whole body except the palms and soles. It provides protection from the sun and particles, helps regulate body temperature, and plays a role in sensory perception Sebaceous glands Glands in the skin that produce sebum, an oily substance that keeps the hair and skin soft, moisturized, and protected. It also inhibits the growth of bacteria and fungi on the skin Sudoriferous glands Glands in the skin that produce sweat, which helps regulate body temperature, excrete water and waste products, and provide some antimicrobial protection Nails Tightly packed, keratinized cells located on the body. They have a visible body, an invisible root embedded in the skin, a lunula (a whitish crescent-shaped area), and a cuticle. Nails protect the fingertips and enhance fine motor skills 4/4