Ch 5

Card Set Information

Ch 5
2012-09-06 16:55:13

Ch 5 Outline-Structure and Function of the Integument-Epidermis-Dermis-Hypodermis-
Show Answers:

  1. Define-Integument
    • Skin
    • -largest organ (7% to 8% of body weight)

    -Two layers

    *Epidermis:superficial layer of stratified squamous epithelium

    • *Dermis:Deeper layer of areolar and dense irregular connective tissues
    • (hypodermis- lies under dermis, mostly adipose connective tissue)
  2. List some functions of Integument

     test question* which of the following is not a function of Integument
    • Protection
    • Prevention of H2O loss
    • Temperature regulation
    • Metabolic regulation
    • Immune defense
    • Sensory reception
    • Excretion/Secretion
  3. Functions of Epidermis
    *Most superficial layer 


    • *Keratinized Stratified squamous epithelium
    • - Keratin is a water-insoluble protein
    • -4 to 5 layers(strata) of distinct cell types
  4. Epidermal Strata

    *list from deep to superficial(as the grow)*
    -Stratum Basale

    -Stratum Spinosum

    -Stratum Granulosum

    -Stratum Lucidum(found only in thick skin)

    • -Stratum Corneum
  5. Stratum Basale
    One layer that undergoes mitosis

    • One layer of cells adjacent to the dermis
  6. Define- Keratinocytes

    Define- Melanocytes

    Define- Tactile Cells
    Keratinocytes: most abundant; produce keratin to waterproof the skin

    • Melanocytes: produce pigment(black, brown, yellow)
    • absorbs UV light to prevent DNA damage

    Tactile: sense touch
  7. Characteristics of Stratum Spinosum
    Several layers thick

    Daughter cells from the Stratum Basale

    • Epidermal Dendritic Cells
    • -phagocytes that engulf invading pathogens
  8. Characteristics of Stratum Granulosum
    3 to 5 layers of Keratinocytes

    cytoplasm fills with keratin filaments

    organelles begin to degrade

    • fully keratinized cells are dead but strong and water-insoluble
  9. Characteristics of Stratum Lucidum
    *Thin, translucent region, 2 to 3 layers thick

    *Present only in thick skin such as sole of feet and palms of hands

    • *Cells lack organelles, filled with eleidin
    • (transparent, intermediate product of keratin maturation)
  10. Characteristics of Corneum  
    *Most superficial layer of epidermis

    *Thickness varies from a few to 30 layers thick depending on location 

    • *Comprised solely of dead keratinocytes
    • (sloughed off by abrasion=dust)
  11. Skin color is determined by 3 pigments
    *Hemoglobin{hee-muh-gloh-bin}: blood pigment: causes light complexions to look pink or blue

    *Melanin{mel-uh-nin}: increases in people exposed to more UV light

    *Carotene{kar-uh-teen}: yellow-orange pigment from food that builds up in the skin
  12. Characteristics of Dermis

    *Two layers of connective tissues:
    Papillary& Reticular
    *Lies deep to the epidermis

    *contains blood vessels

    *important in controlling blood supply

    *Papillary- superficial

    • *Reticular-deeper
  13. Papillary Layer{pap-uh-ler-ee}
    *Directly below stratum basale cells of epidermis

    *Dermal papillae and Epidermal ridges interlock-increase surface between epidermis and dermis

    • *Dermal Papillae supply nutrients to epidermal cells
  14. Recticular Layer[ri-tik-yuh-ler]
    *forms majority of dermis

    • *dense irregular connective tissue, bundles collagen fibers, blood vessels, glands
  15. Nerve fibers are present in Dermis-
    *tactile(touch) receptors

    *control blood flow

    *control glandular secretion
  16. What is the purpose of Vasodilation?
    *Test question*
    *Lowering body temperature

    *Widening blood vessels body heat
  17. Hypodermis(subcutaneous layer)
    *areolar and adipose connective tissues

    *protects underlying structures

    • *stores energy

    • *thermal insulation
  18. Epidermal-


    • *Glands
  19. Horripillation
    Goose bumps
  20. Hair Structure from deep to superficial
    *Hair Papilla: connective tissue, nerves and blood vessels below follicle that support the keratinocytes

    *Hair Bulb: inctrease in hair matrix causes hair growth

    • *Arrector Pili: involuntary smooth muscle attached to hair
    • shaft; responds to EMOTIONAL states(fear or rage) goose bumbs 
  21. Fuctions of Hair

    *Heat retention

    *Facial Expressions

    *Sensory Reception

    *Visual Identification

    *Chemical Signal Dispersal
  22. Exocrine Glands
    2 most common types
    • *Sweat Glands: produce watery solution
    • (merocrine and apocrine)

    *Sebaceous Glands: produce oily secretions
  23. Two rare types Skin Exocrine Glands
    Ceruminous Glands: ear wax

    Mammary Glands: produce milk
  24. Merocrine Sweat Glands & Functions
    *Secretion is 99% H2O, clear, controlled by nervous system

    *Forehead, palms and soles

    Thermoregulation(temp)/Secretion/ Protection
  25. Aprocrine Sweat Glands
    "smell like an ape"
    coiled glands- nipples,armpits,groin, anus

  26. Sebaceous Glands
    *Secrete oily sebum into hair follicles

    *lubricates hair and skin

    • *activates in puberty