What circulation disperses oxygen rich blood throughout the body?

Which of the following identifies the main culprit for america’s increasing weight gain?

Melanocytes and keratinocytes work together in protecting the skin from uv damage when keratinocytes a. provide the melanocyte with a protective shield against abrasion b. maintain the appropriate temperature so the product of the melanocyte will not denature c. maintain the appropriate ph in order for the melanocyte to synthesize melanin granules d. accumulate the melanin granules on their superficial portion, forming a uv-blocking pigment layer

Which one of the following causes people to go through a cycle of losing weight, gaining it back, then lose it again