Integumentary System

  1. dermatology
    branch of medicine involving skin disorders
  2. body's largest organ
    skin: 10-17 square feet for an average adult
  3. functions of the skin
    • 1. protection against injury and chemicals
    • 2. defense against certain microbes
    • 3. prevents dehydration(waterproof)
    • 4. maintains body temperature
    • 5. excretion-sweat(cooling, regulates electrolytes)
    • 6. makes vitamin D
    • 7. stimuli reception
  4. Layers of the skin
    epidermis (outer)

    dermis (inner)
  5. Epidermis
    made up of stratified squamous epithelial tissue, these cells constantly undergo mitosis

    filled with Keratin, a waterproof protein
  6. 5 Layers of the Epidermis
    • 1. Stratum Basale- cuboidal cells constantly dividing; melanocytes are also found here and create melanin(skin color), an albino lacks this pigment
    • 2. Stratum Spinosum
    • 3. Stratum Granulosum
    • 4. Stratum Lucidum- found only in thick skin such as the palms and soles of feet
    • 5. Stratum Corneum- (horny layer) outermost layer, consisting of about 20 layers of cells, protects against microbes
  7. Callus
    thickened part of the Stratum Corneum due to pressure or friction, often found on feet
  8. Corn
    similar to a callus, but the thickened tissue is more separated and distinct
  9. Papillary Region of Dermis
    upper layer of the dermis containing loose connective tissue of collagen and elastic fibers. arranged in ridges and projections to form fingerprints
  10. Reticular Region of Dermis
    thicker, made of irregular dense connective tissue with collagenic and elastic fibers for elasticity and strength.
  11. What Causes Wrinkles?
    the dermis is anchored to the superficial fascia by collagenic fibers which then tot disappear as people get older, leaving the skin wrinkled.
  12. Hair
    • offers protection for the scalp
    • forms from the follicles, composed of a shaft and root
    • shaft consists of dead cells
    • hair will grow as long as the follicle remains healthy arrector pili muscles allow hair to stand erect
  13. Hair Loss Factors
    • interruption of circulation to the scalp
    • illness
    • local diseases (ex. Ringworm)
    • heredity
    • aging
    • activities of male sex hormones
  14. Sebaceous Glands
    attached to hair follicles, very numerous in face and scalp. secretes an oily substance called sebum which serves to lubricate hair and inhibit bacterial growth, but may plug pores and lead to acne, especially active during puberty
  15. Ceruminous Glands
    found in ear canal, secretes cerumin (ear wax)
  16. nail bed
    below nail
  17. lanula
    near the root of the nail, crescent shaped
  18. cuticle
    expands from the skin onto the nail plate
  19. Sweat Glands
    excrete water and some nitrogenous wastes, most numerous in the forehead, soles, palms
  20. Eccrine Glands
    sweat gland which excretes water, salt, trace amounts of nitrogenous wasters; sweat cools the body
  21. Apocrine Glands
    sweat gland which is associated with hair follicles and concentrated in the armpit and genital regions. the secretion is thick and bacteria may proliferate and create an distinctive odor; not as numerous as eccrine glands
  22. Inflammation
    • redness, swelling, heat, pain
    • part of wound repair
  23. Edema
    • swelling causes pain
    • part of wound repair
  24. Wound Repair Steps
    • clots form, white blood cells released
    • scab covers area, basal cells divide rapidly
    • scar tissue may result from more serious wounds
    • internal organs repair themselves, but scar tissue may impair their function
  25. Burns
    • first degree-least serious, heals in a few days (ex. sunburn)
    • second degree-damage to epidermis and superficial dermis; fluid build up between layers leads to blisters
    • third degree-damage to all layers of skin, nerve endings may be destroyed, body's defense is compromised, loss of water, skin grafts may be required, antibiotics
  26. Lund-Browder Chart
    used to determine the percentage of the body burned
  27. Malignant Melanoma
    skin cancer often caused by exposure to U-V light
  28. Basal Cell Carcinoma
    fairly common form of skin cancer, arise from cells of the basal layer of epidermis
Card Set
Integumentary System
Anatomy and Physiology: Skin