Exercise 7 B. Application
Permanent tattoos are made by injecting pigment into the skin. Into which part of the skin is the pigment infected. Epidermis or dermis?
Dermis
Joey had a splinter in his finger. His mother pulled the skin away from the splinter with the sterile needle and remove the splinter. Joey did not feel pain and did not bleed. Explain.
Splinter is in epithelium— avascular— no pain receptors
Cortizone is a steroid that is applied to the skin to reduce inflammation. Cortizone excellent cells within the dermis and can travel through unbroken epidermis to reach cells in the dermis. If the epidermis is such a good barrier, how can Cortizone easily travel through it?
Steroids are lipids Lipids can cross plasma membranes
Explain how dandruff is formed
Stratum Corneum sloughs off
Identify the epidermal layers in which the following cancers arise:
Basal Cell Carcinoma- stratum basale Malignant Melanoma- stratum basale- melanocytes Squamous Cell Carcinoma- stratum spinosum
How do vitiligo and albinism differ? How are they similar?
Both are pale due to decreased amounts of melanin in skin. Vitilego- decreased melanin due to death of melanocytes or inability of melanocytes to function Albinism- inherited defect in enzyme needed to produce melanin
What structure of skin helps you grip a wet glass?
Epidermal ridges
Name the parts of the skin that peel off after a minor sunburn
Epidermis
Pulling a hair out of your head hurts, but cutting your hair doesn't. Explain the difference.
Hairs are attached to follicles which are associated with nerve endings; hair shaft is dead skin
If you had a third degree burn on your scalp, would you expect for your hair to grow back in that area? Explain.
No. Unlikely. Destroys all epidermal and dermal layers
As we age, our skin wrinkles due to changes in collagen and elastic fibers in the dermis and a decrease in their production. Explain why topical application of collagen and elastic fibers would not eliminate wrinkles.
They are proteins and would not diffuse across the cell membrane and into dermis
Describe the mechanism for acquiring a suntan.
UV light in sunlight damages cellular DNA. Cellular repair processes stimulate melanocytes to produce melanin. Melanin helps protect cells from further damage from UV light.
