The Integumentary System

Skin and its accesory organs

(Superficial)The outer layer of skin. composed of squamous epithelium. Many specialized cells.

(deep) The inner layer. thicker than the outer layer. with few cells and connective tissue.heavily embedded with collagen , elastin, and reticular fibers. richly supplied with nerve fibers, blood vessels, and lymphatic vessels. major portion of your hair follicle as well as oil and sweat glands reside here but are derived from the outer layer.

Cutaneous membrane composes 16% of a person's body weight.

Keratinocytes, melanocytes, langerhans, merkle

Produce keratin which gives the epidermis its "water proofing" abilities. cells come from the stratum basale. Rub off everyday to give a new epidermis every 25-45 days.

Thickening of epidermis

Spider shaped epithelial cells that synthesize the pigment melanin (yellow to brown to black)

Concentrated melanin

Anchors the epidermis to the dermis and separates these two skin layers.

Beneath the dermis. consisting of loose connective and adipose tissue. binding the skin to the underlying organs. (Hypodermis)

Same as subcutaneous layer. (def:------)

Deepest layer of epidermal cells. close to the dermis and noursished by dermal blood vessels. Youngest keratinocytes. cells undergo mitosis and moce upward. melanocytes found and produced here. (Stratum germinativum) first layer.

Same as Stratum basale (def:-----)

Older cells in epidermis