The skin has up to how many layers of ectodermal tissue
guarding muscles, bones, ligaments and internal organs?
Human skin is similar to most of the other what?
A: Mammals' skin, and it is very similar to pig skin.
Though nearly all human skin is covered with hair
follicles, it can appear what?
What are two general types of skin?
A: Hairy and glabrous skin (hairless).
The adjective cutaneous literally means what?
A: "Of the skin" (from Latin cutis, skin).
Because it interfaces with the environment, skin plays
an important immunity role in protecting the body against what?
A: Pathogens and excessive water loss.
What are its other functions?
A: Insulation, temperature regulation, sensation, synthesis of vitamin D, and the protection of vitamin B folates.
How does severely damaged skin try to heal?
A: By forming scar tissue.
Skin provides a rich and diverse habitat for what?
Human skin shares anatomical, physiological,
biochemical and immunological properties with other mammalian lines,
A: Pig skin.
Pig skin shares similar epidermal and dermal what?
A: Thickness ratios to human skin.
Pig and human skin share what similar patterns?
A: Hair follicle and blood vessel.
Skin has mesodermal cells, pigmentation, such as
melanin provided by melanocytes, which do what?
A: Absorb some of the potentially dangerous ultraviolet radiation (UV) in sunlight.
It also contains DNA repair enzymes that help do what?
A: Reverse UV damage.
One form predominantly produced by UV light, malignant
melanoma, is particularly invasive, causing it to do what?
A: To spread quickly, and can often be deadly.
In terms of surface area, the skin is the second
How big in surface area is the skin for the average
A: The skin has a surface area of from 1.5–2.0 square meters (16–22 sq ft).
The thickness of the skin varies considerably over all
parts of the body, and between men and women and whom?
A: The young and the old.
One average square inch (6.5 cm2) of skin holds what?
A: 650 sweat glands, 20 blood vessels, 60,000 melanocytes, and more than 1,000 nerve endings.
Skin is composed of what three primary layers?
A: The epidermis, the dermis and the hypodermis.
Epidermis, "epi" coming from the Greek meaning "over"
or "upon", is what?
A: The outermost layer of the skin.
It forms the waterproof, protective wrap over the
body's surface which also serves as a barrier to what?
The epidermis contains no what?
A: Blood vessels.
Cells in the deepest layers are nourished almost
exclusively by diffused oxygen from what?
A: The surrounding air and to a far lesser degree by blood capillaries extending to the outer layers of the dermis.