Anatomy and Physiology Fisher

Anatomy and Physiology Fisher Chapter 6: Skin and Integumentary System Directions: Answer these questions in your notebook. 1. How is the epidermis formed? Stratum basale cells divide and grow, pushing the other cells away from the dermis toward the skin surface, the farther the cells move, the less blood supply, and they die—keratinizing first (p. 114) 2. What is the difference between the stratum basale and the stratum corneum? Stratum basale—deepest layer of epidermis where mitosis occurs; stratum corneum—most superficial layer of epidermis, tough, dead, tightly packed cells (keratinized). P. 114 3. Medicine can be injected through 3 different types of injections. Describe the difference between each type: p.114 a. Subcutaneous injection under dermis, in subcutaneous (hypodermis) b. Intradermal injection within skin (w/in dermis) c. Intramuscular injection into muscle, below skin d. Which type is also known as a hypodermic injection? Intramuscular 4. Transdermal patches are also used to administer drugs. How does the drug get into the blood stream in this method? Contains a small reservoir of the drug that passes through a permeable membrane at a known rate then diffuses into the epidermis and dermis into the blood vessels. P. 114 5. What are three uses for a transdermal patch? Stop smoking, chest pain (due to heart disease), motion sickness p. 114 6. When cell division increases on areas of the skin that are rubbed or pressed regularly, this causes what? Calluses on palms and soles, corns on toes p. 114 7. Cytoplasmic extensions transfer melanin through a process called cytocrine secretion. Describe this process. Melanocytes(melanin production)lie in deepest portion of epidermis (stratum basale/spinosum) but extensions of the cytoplasm pass between other cells transferring melanin granules into these other cells p. 115 8. What factors influence skin color? Genetics, sunlight, x-rays, blood in dermal vessels, diet, biochemical imbalances p. 116 9. What are bedsores and how do they form?

1 modified 4/8/2018 Anatomy and Physiology Fisher Chapter 6: Skin and Integumentary System Weight of body pressing against one area for prolonged periods (especially where bony projections are) can cause the cells to die, and cut off the blood supply to the area. The breakdown of the tissue can cause a pressure ulcer (decubitus ulcer) which is a bedsore. P. 116 10. How is vitamin D related to the skin? Can form from dehydrocholesterol made by cells in the digestive system, when it reaches to skin and is exposed to UV from sun, it is converted to another chemical that becomes vitamin D. p. 116 11. How do keratinocytes assist the immune system? By producing hormonelinke substances that simulate development of T lymphocytes (WBCs) that defend against infectious bacteria and viruses. P. 116. 12. What kinds of tissues make up the dermis? Connective, smooth muscle, epithelial, nervous p.p. 117-120 13. Describe the structure of a nail bed. Specialized epithelial cells that are continuous with the epithelium of the skin. P. 117 14. What is the most actively growing region of the nail? The base of the nail plate, covered by the lunula (whitish, thickened, half-moon shaped region) p. 117 15. How does hair form? Epidermal cells at base of hair follicle that then grow and divide and push older cells away toward surface becoming keratinized p. 117-118 16. What are 3 areas on the body not covered in hair? Palms, soles, lips, nipples, and parts of external reproductive organs p. 117 17. The nails, hair, and skin all develop in what similar way? Epidermal cells at base grow, divide, pushing older cells toward surface where they keratinize (CH. 6) 18. Sebum is the name for what substance secreted by the skin? Oil p. 118 19. What is the difference between apocrine and eccrine sweat glands? Apocrine: become active at puberty and cover the axillary and groin regions (respond to emotional upset, fright, or pain) ; eccrine: are always active and cover the forehead, neck and back (respond to heat and physical activity) p.118-119 20.Sweat consists of what substances? Water, salt, urea and uric acid p. 119

2 modified 4/8/2018 Anatomy and Physiology Fisher Chapter 6: Skin and Integumentary System 21. Give two examples of modified sweat glands. Mammary glands (milk), and ceruminous glands (earwax) p. 119 22.Describe hypothermia, and the body’s attempt to maintain homeostasis. Body T falls, muscles in walls of blood vessels contract, blood flow decreases, sweat glands are inactive, nervous system stimulates skeletal muscle to contract, small groups of muscles contract rhythmically (shivering) p. 120 23.Describe hyperthermia, and the body’s attempt to maintain homeostasis. Body T rises, nerve impulses stimulate release of heat, blood carries heat to hypothalamus in brain which signals muscles in the dermal blood vessels to relax (vasodilation), more blood enters them and heat escapes to outside. Eccrine sweat glands stimulated by nerves to become active and to release sweat onto ths skin surface to evaporate, thereby carrying more heat away. P.120 24.How does inflammation help a wound heal? Blood vessels dilate and become more permeable, forcing fluids to leave the blood vessels and enter damaged tissues. More nutrients and oxygen are provided, which aids healing. Inflammation causes redness, heat, swelling, and pain. P. 120-121 25.How are the steps necessary for a wound to heal in the dermis different from those in the epidermis? Epithelial cells are stimulated to divide more rapidly to fill gap in epidermis. If dermis or subcutaneous, blood vessels break, blood clots and forms scab. Fibroblasts migrate into the region and form collagenous fibers to bind edges together, blood vessels extend into area beneath scab, phagocytic cells remove dead cells, and tissues are replaced. Scab sloughs off. If extensive, may leave scar. P. 121 26.What role do phagocytic cells play in wound healing? Get rid of dead cells and other debris p. 121 27.What is the difference between a first degree, second degree, and third degree burn? 1st: epidermis alone (superficial partial-thickness burn 2nd: epidermis and some dermis (deep partial-thickness) 3rd: epidermis, dermis, and accessory organs (full-thickness) p. 121 28.Healing in large open wounds involves granulations, what are these?

3 modified 4/8/2018 Anatomy and Physiology Fisher Chapter 6: Skin and Integumentary System Rounded masses consisting of new branch of a blood vessel and cluster of collagen-secreting fibroblasts nourished by it. Often the blood vessels are resorbed and fibroblasts migrate away leaving a scar. P. 121 29.When reading the Clinical Connection on p. 123 of the text, the stem cells found in the patients were likely formed from what? Dedifferentiated cells p. 123 30.What was the difference in the patients who were treated with epidermal growth factor compared to the other patients? Stem cells were more abundant grouped into “stem cell islands” that traversed more than one layer; those without treatment stem cells were scattered and in one layer at the bottom of the basement membrane. P. 123

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