Intergumentary System

• 1. What organs make up the integumentary system?

  skin, hair, glands, and nails
• 2. How does the integumentary system offer protection?

  The skin protects against abrasion and UV light. It also keeps micro-organisms from entering the body and prevents dehydration by reducing water-loss from the body.
• 3. What sensations are detected by the I. system.

  touch, temperature, and pain
• 4. In what two ways does the I system regulate body temperature?

  - The amount of blood flow and the activity: when blood vessels in dermis dilate, more warm blood flows from deeper structures to the skin and heat loss increases across the epidermis (vasoconstriction and vasodilation)- sweat glands regulate body temperature.
• 5. What vitamin is made in the skin through interaction with UV radiation?

  Vitamin D production
• 6. How does the skin work in the process of excretion?

  excreted through the gland and the skin
• 7. What is the hypodermis?

  the skin rests on the hypodermis. The hypodermis consists of loose connective tissue with cells in it including fibroblasts, adipose cells, and macrophages. The hypodermis contains the major blood vessels that supply the skin.
• 7. What tissue makes up the hypodermis?

  loose connective tissue
• 7. What are the cells found in the hypodermis?

  The cells include fibroblasts, adipose cells and macrophages
• 7. What are some of the other names for the hypodermis?

  subcutaneous tissue or superficial fascia
• 8. What kind of fibers gives the dermis structural strength?

  collagen fibers
• 9. What are stretch marks?

  rupture in the dermal layer, your hypodermis shows through
• 10. Name the two layers of the dermis. Which layer is responsible for making ridges called fingerprints?

  reticular layer (below), papillary (above); Papillary layer, ridges project up in the epidermis
• 11. What kind of lines are created by the fiber orientations in the dermis?


  cleavage lines
• 12. Why does a surgeon need to know information about cleavage lines?

  because incisions are made parallel to cleavage lines
• 13. What is meant by the epidermis being avascular?

  epidermis is the top layer, layer in which does not get blood
• 14. Keratinocytes function


  - Produce keratin- Keratin makes cells more durable- Help epidermis resist abrasion and reduce water loss
• 14. Melanocytes function


  produce melanin, skin color
• 14. Langerhan's function

  makeup the immune system of the epidermis
• 14. Merkel's function


  detect light, touch and pressure
• 15. Define desquamation and describe the adaptive advantage of the process.

  means the older cells (top layer) slough off, has an adaptive advantage because shedding outside cells carry away many bacteria
• 16. What is keratinization? In what two ways is the presence of keratin in the epidermis helpful?

  - When Keratinocytes move from the deeper epidermal layers to the surface, keratinocytes change shape and chemical composition - this is keratinization - Cells eventually die and produce an outer layer of dead, hard cells that resist abrasion and form a permeable layer- The keratin forms a layer which resists abrasion and become impermeable
• 17. Stratum basale/stratum germinativum function

  - Is the deepest portion, single layer and is attached to the basement membrane, where keratinization begins- Structural strength is provided by hemidesmosomes- Keratinocyte stem cells of this layer undergo mitotic divisions every 19 days- One daughter cell remains a stem cell in the stratum basale and divides again, but the other daughter cell is pushed toward the surface and becomes keratinized- Produces cells of the most superficial strata- Melanocytes produce and contribute melanin which protects against UV light
• 17. Stratum spinosum function

  - Consists of 8-10 layers of many-sided cells has limited cell division, developing fibers of keratin are found here and cells are becoming flattened- Additional keratin fibers and lipid-filled organelles called lamellar bodies form inside the keratinocytes- Produce keratin fibers; lamellar bodies form inside keratinocytes
• 17. Stratum granulosum function

  - Flattened, diamond shaped cells with long axes that are oriented parallel to the surface. - Produces keratohyalin granules; lamellar bodies form inside keratinocytes - Lamellar bodies release lipids from cells; cells die - Keratin fibers and keratohyalin granules with the cytoplasm do not degenerate
• 17. Stratum lucidum function

  - Thin, clear zone above the stratum granulosum - Several layers of dead cells with indistinct boundaries - only present in a few areas of the body (thick and thin skin) - Disperses keratohyalin around keratin fibers
• 17. Stratum corneum


  - Made up of many layers of dead epithelial cells (cornified cells) that are flattened, shed continuously, joined by desmosomes - Provides structural strength due to keratin within cells- Prevents water loss due to lipids surrounding cells - Sloughing off of most superficial cells resists abrasion
• 18. What two layers make up the Stratum germinativum?

  stratum basale, stratum spinosum
• 19. Describe the difference in structure and location of thick skin and thin skin.

  - thick skin has all 5 epithelial strata and the stratum corneum, has many layers of cells; found in the palms, finger tips and soles - found in areas subject to friction- thin skin is more flexible than thick skin, stratum lucidum is missing and the thin skin covers the rest of your body; hair grows here
• 20. What is the purpose of melanin in the skin?

  protects from excessive UV radiation
• Skin color is determined by... (3)

  - pigments- blood circulating through skin - thickness of stratum corneum
• 21. Define albinism.

  a deficiency of melanin pigment
• 22. What is the association of melanin production and pregnancy?

  melanin production is increased during pregnancy especially along the linea alba, and the areola
• 23. What color is carotene?

  yellow
• 24. What color does circulating blood contribute to the skin?

  red
• 25. Under what situation would circulating blood cause the reddish hue of the skin to increase?

  blushing, anger or inflammation
• 26. What is cyanosis? When does it occur? What is the bluish cast of the skin caused by?

  blue color of the skin, occurs when there is inadequate oxygen in the blood, bluish cast is caused when dark red color of blood mixes with yellow color of the skin
• 27. How does the thickness of the stratum corneum lead to different skin color?

  Thickness leads to lighter colored areas.
• 28. Where is melanin made? How does it get to the other layers of the epidermis?

  It is produced by the melanocyte and is transferred into the surrounding cells by cellular extensions
• 29. What is true about the number of melanocytes possessed by different races of people?

  different races have the same number of melanocytes