Ch 4: anatomic structures of the integumentary system

skin

organ covering the body; made up of layers

epidermis

outer layer of skin; protects the body from the external environment

keratin

scleroprotein component of the horny, or cornified, layer of the epidermis. Also, the primary component of the hair and nails

melanin

dark pigment produced by melanocytes; amount present determines skin color

hair

compressed, keratinized cells that arise from hair follicles, the sacs that enclose the hair fibers

nails

horny plates made from flattened epithelial cells; found on the dorsal surface of the ends of the fingers and toes

sebaceous glands

secrete sebum (oil) into the hair follicles where the hair shaft pass through the dermis

sudoriferous glands

tiny, coiled, tubular structures that emerge through pores on the skin’s surface and secrete sweat

dermis

inner layer of skin; responsible for its flexibility and mechanical strength

hypodermis

layer between the dermis and the underlying tissues and organs; contains adipose tissue (fat), connective tissue, nerves, and blood vessels