INTEGUMENTARY SYSTEM
Structure of the skin:
The skin consists of two layers:
I. Epidermis:
It is covered by a keratin layer making it waterproof.
Epidermal ridges are seen on the palmar aspect of hands and fingers (prints).
II. Dermis: it consists of:
1. Collagen fibers.
2. Elastic fibers
3. Blood vessels.
4. Lymphatic vessels.
5. Nerves.
Skin appendages:
1- Hairs.
2- Nails: develop from epidermis. It is formed of a root, body, and free border.
3- Sebaceous glands: their ducts open in the hair follicles.
4- Sweat glands: open on the surface of the skin.
Structure of skin