Lesson 3
The Human Integumentary and Fascial Systems

3.1 General Information

An organ system is a group of organs together performing an overall function. Portions of two organ systems, the integumentary and fascial systems, are represented in figure 3-1.

Figure 3-1. The integument and related structures.

The integumentary system includes the integument proper and the integumentary derivatives. We know the integument proper as the skin. It is the outermost covering of the whole body. The integumentary derivatives include the hairs, nails, and various glands of the skin.

A fascia is a sheet or collection of fibrous connective tissue (FCT). The superficial fascia is the connective tissue which lies immediately beneath the skin and is often known as the subcutaneous layer. Deep fasciae (plural) form envelopes for muscles and other organs and fill spaces. One deep fascial membrane is the third envelope of the whole body, beneath the skin and the subcutaneous layer. It is known as the investing deep fascia.

3-2. COVERINGS OF THE HUMAN BODY

The entire body is surrounded by three layers or envelopes, one inside the other.
These coverings separate the body from the external environment. These envelopes include (from outside inward)--the skin (the integument proper), the subcutaneous layer, and the investing deep fascia.