Chapter 6: Thick/Thin, Color, Markings (dealing with epidermis)

What is thick skin?

• palms of hands, soles of feet

• contains all five layers of epidermal strata

• sweat glands but no hair follicles or sebaceous glands

What is thin skin?

• covers most of body

• lacks a stratum lucidum

• sweat glands, hair follicles, and sebaceous glands

What is normal skin color from?

hemoglobin, melanin, carotene

What are things that affect skin color?

hemoglobin, melanin, carotene, cyanosis, erythema, pallor, jaundice, bruise

What color does hemoglobin bring?

• oxygen-binding protein in red blood cells,

• bright red color upon binding oxygen

What color does melanin bring?

• dark pigment produced in melanocytes

• transferred to keratinocytes

• amount in skin varies (heredity, UV exposure)

• Albinism: Melanocytes unable to produce melanin

What color does carotene bring?

yellow-orange pigment acquired from some vegetables

What color does cyanosis bring?

blue, due to a lack of oxygen

What color does erythema bring?

• red

• due to fever or inflammation

What color does pallor bring?

white/pale, due to shock or anemia

What color does jaundice bring?

yellow, due to liver disorder

What color does a bruise bring?

black/blue/purple, due to hemorrhage

What are some skin markings?

nevus (moles), freckles, hemangiomas, friction ridges

What are nevus (moles)?

• localized overgrowth of melanocytes

• should be monitored for changes suggesting malignancy

What are freckles?

• yellowish or brown spots

• localized areas of increased melanocyte activity

What are hemangiomas?

skin discoloration due to benign blood vessel tumor

What are friction ridges?

large folds and valleys of dermis and epidermis, fingerprints