Final answer:
The skin consists of the epidermis, the outer protective layer and the dermis below it, containing connective tissue, blood vessels, and glands. Dead, flattened cells compose the outermost portion of the epidermis, seen under a microscope. The fatty tissue under the skin provides insulation but is not part of the skin itself.
Step-by-step explanation:
The skin is composed of two main layers: the epidermis and the dermis. Beneath the dermis lies a layer of fatty tissue that is not considered part of the skin but provides insulation and cushioning.
The epidermis is the outermost layer and serves as the body's primary barrier against the environment. This layer is continuously shed and replaced. Zooming in on this layer using a microscope, you would notice that the outermost cells are flattened and lack nuclei, indicating they are dead and will soon slough off.
The dermis is further divided into two layers: the papillary layer, which is the upper layer and contains a thin arrangement of collagen fibers, and the reticular layer, composed of thicker collagen fibers that provide structure and elasticity to the skin.