Integumentary System

• Skin: largest organ of the human body / Hair / Nails / Sweat glands
• Integumentary System: Provides protection, regulates temperature, prevents water loss and produces Vitamin D precursors. Consists of skin, hair, nails, and sweat glands.
• Integumentary System: Outermost to protect the inside
• Integumentary System Functions

  Protection: dehydration, UV, microbes

  Sensation: sensory receptors detect heat, cold, touch, pressure, pain

  Vitamin D production: needed in Calcium homeostasis

  Temperature Regulation: amount of blood flow and activity of sweat glands.

  Excretion- release waste products & thru gland secretion.
• Anatomy: study about the body structure
• Physiology: Study of the functions of the body systems.
• UV=Ultraviolet Rays
• Vitamin D activation already is in the skin that being produce when expose to sunlight.
• When cold, blood flows in the cheeks to preserve body heat. When hot, sweating give you cooling sensation and release body heat.
• Epidermis: Thinner layer, superficial, outer surface, Stratified Squamous Epithelium
• Dermis: Thicker layer, called true skin where you can find all the structure and functions.
• Hypodermis: Under the skin
• The two major layers of skin is only epidermis and dermis.
• Epidermis: layer of stratified squamous epithelium, prevents water loss, resists abrasion, keratinization, forms strata or layers.
• Dermis: Layer of dense connective tissue with fibroblast, fat cells, and macrophages. Collagen and elastic fibers are responsible for most of the structural stuctural strength, cleavage and tension lines, dermal papillae.
• Strata of Epidermis from Superficial to Deepest:

  • Stratum Corneum
  • Stratum Lucidum
  • Stratum Granulosum
  • Stratum Spinosum
  • Stratum Basale
• Dermal papillae: extension of dermis to epidermis
• Callus: Thick skin formed caused by prone to damage.
• Corn: skin in the joints and knuckes.
• Melanosomes are produced by the Golgi apparatus of the melanocyte.
• Melanosomes move into melanocyte cell processes.
• Epithelial cells phagocytize the tips of the melanocyte cell processes.
• The melanosomes, which were produced inside the melanocytes, have been transferred to epithelial cells and are now inside them.
• Dermis: where you can find all the structure and functions of the skin
• Blood vessels: blood flow which regulates our normal body temperature in dermis
• Melanin: is the pigment give color in human skin, brown to black
• More amount melanin produced more darker, less amount of melanin the lighter.
• Melanocyte: melanin producing cell
• Melanosomes: Small sacs carrying the pigment melanin
• Phagocytized = Engulfed
• More melanin more naturally protected from UV rays
• Areas of skin without hair

  • Palms
  • Soles of the feet
  • Lips
  • Nipples
  • Genitalia
  • Distal wnd of fingers and toes
• Hair follicle: where hair grows
• Hair root: below the skin and hair that is not visible yet
• Hair shaft: above skin and is visible
• Hair follicle begins in the epidermis and invaginates formingly deep down into the dermis to form its structure
• Hair bulb: found at the base of the hair root
• Cortex: outer hard layer of the hair
• Medulla: Softer center of the hair
• Cuticle: made up of single layer of cells, that covers the cortex