What are the functions of the skin?

Derivatives of the Skin

Sweat Glands

• ~3 million of them throughout the body!• Per person!

Eccrine Sweat Glands

• Releases into skin surface • Most abundant sweat glands• Also on soles, palms, and forehead• Secretory part in dermis

What makes you sweat

Apocrine Sweat Glands

• Empty into hair follicles • Larger then eccrine• Axillary and anogenital areas • Fatty and protein substances • Milky and Yellowish color… oooo!• Released during pain, stress, and sex?

Ceruminous Glands

• Release earwax!

Mammary Glands

• Secrete milk!• We’ll talk about them a little bit later

Sebaceous Glands

• Oil glands – all over body• Produce sebum• Release into hair follicle – Maybe a pore

• Hormones stimulate

Hair and Hair Follicles

• What is the point?

• Some people get a lot… lucky!

Some people don’t get any

Hair

• Growths of the epidermis variously distributed over the body.

• Dead keratinized cells

• DIVIDED INTO TWO MAJOR DIVISIONS:• 1. THE ROOT• 2. THE SHAFT

THE ROOT

• Portion just below the surface that penetrates into the dermis.

• Surrounding the root is a hair follicle• At the base of each follicle is an enlarged

structure called a bulb.

Hair Follicle

• Each follicle gets– Arrector pilli – smooth muscle– Nerves! – root hair plexus– Hair papilla – capillaries!

NAILS

• Hard keratinized cells of the epidermis

• 3 parts:• 1. Nail body- portion that is visible • 2. Free edge-Any part that may project beyond

the distal end of the digit. • 3. Nail root-Hidden in proximal nail groove

Structure of a hair follice

Hair Growth