The outer layer: epidermis

Made up of three sub-layers:

the outer-most layer - the stratus corneum (or horny layer) contains continually shedding, dead keratinocytes (the primary cell type of the epidermis).

the middle layer - contains layers of living keratinocytes (also called squamous cells). Keratin, a protein formed by these cells, helps provide the skin what it needs to protect the rest of the body.

the inner layer - the basal layer that contains basal cells. Basal cells continually divide, forming new keratinocytes and replacing the old ones that are shed from the skin's surface.

Also contained in the epidermis:

melanocytes - a type of cell that resides in the epidermis that produces melanin (a protective pigment that gives the skin its color).

The middle layer: dermis

Made up of the following, which are all held together by a protein called collagen:

1. blood vessels
2. lymph vessels
3. hair follicles
4. sweat glands

collagen - made by fibroblasts (skin cells that give the skin its strength and resilience).

The deepest layer: subcutis

Also known as the subcutaneous layer, the subcutis forms a network of collagen and fat cells. The subcutis is responsible for conserving the body's heat, while helping to protect the organs of the body from injury by acting as a "shock-absorber".