Accessory structures of the skin

Nails

Tightly packed, hard, dead, keratinized epidermal cells

Nail body

Visible part of the nail

Nail Root

Portion that is not visible (A)

Eponychium

- Cuticle

- Stratum corenum of the epidermis

Lunula

Thick white part of the nail

Nail Bed

Skin below nail plate

Free Edge

Extends past the finger or toe

Hyponychium

Secures nail to the fingertip

Nail Matrix

- Epithelium proximal to the nail root

- Contains dividing cells (J)

Phalanx

- Finger bone (I)

Dermis

- H

Epidermis

- G

Hair follicle

cavity or sac from which the hair originates

Hair shaft

part of hair that is above the epidermis but not anchored to the follicle

Hair root

part of hair that is below the epidermis anchored to the follicle

Hair papilla

mass of connective tissue, blood capillaries, and nerve endings at the base of the hair follicle

Hair function

protects the body (ex. eyebrow hair preventing sweat and other particles from falling into the eyes)

Sensitive to air movement or other disturbances in the environment

Insulation to keep the body warm

How does the nail root contribute to nail growth?

The nail root has a matrix of proliferating cells from the stratum basale that enables the nail to grow continuously

Eccrine sweat glands

coiled, exit at skin pores

most abundantly located in the palms of the hand, the soles of the feet, and the forehead

Apocrine sweat glands

larger, coiled, exit into hair follicle

Usually associated with hair follicles located in densely hairy areas such as the armpits and genitals

Why do apocrine glands produce an odor?

Apocrine sweat includes organic compounds that make the sweat thicker and subject to bacterial decomposition, leading to an odor

Sebum

a mixture of lipids that are secreted onto the skin, lubricating the dead and dry layer of keratinized cells, keeping it pliable