Ch 6.2- Integumentary Structures Derived from the Epidermis Flashcards
What is the main part of the nail called?
Nail body
What is the name for the cuticle?
Eponychium
Nai bed
The part of the epidermis under the nail body.
Nail matrix
Thickened part of the nail bed just beneath the nail root.
Lunula
White part of the nail close to the eponychium.
Hyponychium
The are of thickened epidermis just under the free edge of the nail.
Pilus
Single hair
What are the three types of hair?
Lanugo, vellus, and terminal hair.
Lanugo hair
the fine hair on new born babies.
Vellus hair
hair found on limbs
Terminal hair
hair on the scalp.
Three zones of hair?
Hair bulb, root, and shaft.
Hair bulb
swelling at the base of hair where it originates in the dermis
Hair papilla
Epithelium at the base of the bulb made of connective tissue with tiny blood vessels and nerves.
Hair root
part of hair extending from the bulb of to the skins surface.
Hair shaft
portion of hair that extends beyond the skins surface.
Hair matrix
Immediately adjacent to the hair papilla where special type of keratinization occurs.
Medulla
Remnant of the soft core of hair matrix. Contains loosely arranged cells and air spaces and contains soft flexible keratin.
Cortex
several layers of cells close to the cells outer surface.
Hair Cuticle
Single layer of cells that coats the hair cortex.
Hair follicle
Oblique tube that surrounds the hair root. Always extends into the dermis and sometimes into the subcutaneous layers.
Two layers of hair follicle
Outer connective tissue root sheath from the dermis, and epithelial root sheath from the epidermis.
Arrector pilli
Thin ribbons of smooth muscle that attach to the hair follicle.
Anagen phase
Phase of hair growth 18 months to 7 years. 80-95% of hair on scalp is made up of this kind of hair.