Anatomy Lab Integumentary System

  1. integument
    • skin that covers body
    • aka cutaneous membrane
    • bodies largest organ
  2. integumentary system
    • contains skin and its derivatives
    • nails, hair, sweat glands, and sebaceous glands
  3. dermatology
    scientific study and treatment of the integumentary system
  4. two layers of the integument
    • stratified squamous epithelium called the epidermis
    • deeper layer of dense irregular and areoular loose connective tissue called the dermis
  5. subcutaneous layer
    • not part of the integumentary system
    • deep to the dermis
    • composed of areolar and adipose connective tissue
    • aka the hypodermis
    • involved in structure and function of the skin
  6. functions of the integument
    • protection
    • prevention of water loss
    • temperature regulation
    • immune defense
    • sensory reception
    • excretion
  7. integument function of protection
    • physical barrier that protects from injury, trauma, bumps, and scrapes, harmful chemicals, toxins, microbes, and exssesive heat or cold, solar radiation
    • can withstand stress and regenerate itself continuously
  8. selectively permeable
    can absorb certain chemicals and drugs, some things can pass through while others cannot
  9. integument function of prevention of water loss
    water cannot easily enter or exit the skin, unless it is specifically secreted by the sweat glands
  10. what is a major concern when an individual is burned
    dehydration because they have lost the protective barrier
  11. transepidermal water loss (TEWL)
    some interstitial fluid slowly escapes through the epidermis to the surface where they evaporate into the surrounding air
  12. how much water is lost per day by evaporation from the skin or from respiratory pathways from breathing
    500 ml
  13. insensible perspiration
    release of water vapor from sweat glands under normal circumstances when we are not sweating
  14. sensible perspiration
    visible sweating
  15. how does body help slow down TEWL
    the water released during insensible perspiration mixes with sebaceous secretions and produce a thin acidic film that forms an oily barrier over skin, also helps invasion of bacteria
  16. integument function of temperature regulation
    • when body is too warm and needs to disipate heat the diameter of blood vessels in the dermis enlarges to permit more blood flow through the dermis and sweat glands release fluid onto skin surface, as more blood flows through dermal vessels the warmth is dissipated through the skin and body cools off by evaporation of sweat
    • when the body is cold and needs to conserve heat the blood vessels in the dermis constrict to reduce blood flow in an effort to conserve heat blood is shunted to deep body tissues and less blood flows in the dermal blood vessels
  17. vitamin D
    a cholesterol derivative syntehsized from cholecalciferol
  18. cholecalciferol
    produced by some epidermal cells when exposed to UV radiation
  19. calcitriol
    • synthesized from the cholecalciferol by some endocrine cells in the kidney
    • the active form of vitamin D3,
    • hormone that promotes calcium and phosphorous absorption from ingested materials across the wall of the smaller intestine
    • important in regulating the levels of calcium and phosphate in the blood
  20. integument function in immune defense
    immune cells called epidermal dendritic cells or langerhans cells play an important role in initiating an immune response by phagocytizing pathogens that have penetrated the epidermis and also against epidermal cancer cells
  21. integument function of sensory reception
    receptors in skin are associated with nerve endings that detect heat, cold, touch, pressure, texture, and vibration
  22. taxtile cells
    • aka merkel cells
    • large specialized epithelial cells that stimulate specific sensory nerve endings when they are distorted by fine touch or pressure
  23. integument function of excretion
    • we secrete waste products being secreted onto the skin surface
    • substances include water, salts, and urea, a nitrogen containing waste product of body cells
    • skin contains sebacous glands that secrete an oily material called sebum which lubricates¬† skin surface and hair
  24. epidermis
    • epithelium of the integument
    • a keritinized stratified squamous epithelium
    • avascular
    • acquired nutrients through diffusion from the underlying dermis
  25. stratum basale
    • deepest epidermal layer
    • single layer of cells range from cuboidal to low columnar in appearance
    • tightly attached to underlying basement membrane that seperates the epidermis from the connective tissue of the adjacent dermis
  26. three types of cells occupy stratum basale
    • keratinocytes
    • melanocytes
    • tactile cells
  27. keratinocytes
    • most abundant cell type in the epidermis and are found throughout all epidermal strata
    • they make the protein keratin
  28. keratin
    • family of fibrous structural proteins that are both tough and insoluble
    • fibrous keratin molecules can twist and intertwine around each other to form helical intermediate filaments of the cytoskeleton
    • structure in cells gives skin its strength and makes epidermis almost waterproof
  29. melanocytes
    • long branching cytoplasmic processes and are scattered among the keratinocytes of stratum basale
    • transfer pigment granules called melanosomes by phagocytosis or exocytosis into keratinocytes
    • malanosomes gather around the nucleus of keratinocytes and shields the DNA within from uv radiation
  30. tactile cells
    • few in number
    • sensitive to touch and when compressed they release chemicals that stimulate sensory nerve endings, providing information about objects touching the skin
  31. stratum spinosum
    • made of several layers of polygonal keratinocytes
    • aka the spiny layer
    • nondividing keratinocytes in the stratum spinosum attach to their neighbors by many intracellular junctions called desmosomes
    • also contain epidermal dendritic cells that help fight infection, contain phagocytic abilities
  32. stratum granulosum
    • granular layer
    • consists of three to five layers of keratinocytes superficial to stratum spinosum
    • keratinization begins here
  33. keratinization
    • keratinocytes fill up with keratin
    • as cells pass through stratum granulosum and true keratin filaments develop cells become thiner and flatter
    • membranes thicken and become less permeable
    • nucleus and organelles disintegrate and cell dies
    • cell is not fully keratinized until until it reaches more superficial epidermal layers
  34. stratum lucidum
    • clear layer
    • thin transulecent region about two or three cell layers thick
    • found only in thick skin such as palms and soles of feet
    • cells in this layer appear pale and featurless and have indistinct boundaries
    • keratinocytes in this layer are flattened and filled with eleidin
  35. eleidin
    intermediate product in process of keratin maturation
  36. stratum corneum
    • most superficial layer of epidermis
    • about 20-30 layers of dead scaly interlocking keratinized cells called corneoucytes
    • cells are anucleate and tightly packed together
  37. life time of skin cells
    • migration of keratinocyte to stratum corneum from stratum basale occurs during first 2 weeks of life, dead keratinized cell remains for additional 2 weeks exposed on stratum corneum layer
    • keratinocytes are present for about 1 month following their formation
  38. skin thickenss throughout most of the body
  39. transdermal administration
    drugs being administrated through the skin
  40. thick skin
    • found on palms of hands, soles of feet, and corresponding surfaces of fingers and toes
    • contain all 5 epidermal strata
    • 400-600 micrometers thick
    • contains sweat glands but no hair follicles or sebaceous glands
  41. thin skin
    • covers most of body
    • epidermis lacks the stratum lucidum
    • only has 4 epidermal a
    • contains hair follicles, sebacous glands, and sweat glands
    • 75-150 micrometers thick
Card Set
Anatomy Lab Integumentary System
Integumentary System