3.3 The Fascial System of the Human Body

Most of the fibrous connective tissues (FCT) are fascial. These may occur as sheets or masses. NOT included in this definition are the tendons, ligaments, or aponeuroses (wide flat tendons). The different fasciae have varying proportions of white fibers, yellow fibers, fat, and tissue fluid. Some serve as membranes to enclose the body and its parts. Fasciae also help to support some organs and allow motions between other organs to be easier.

SUPERFICIAL FASCIA

The superficial fascia is the second envelope of the body. It is the layer between the skin (integument proper) and the investing deep fascial envelope. It is often called the subcutaneous layer, but it is technically not a part of the integumentary system as such. The superficial fascia is made up primarily of loose areolar FCT with the spaces filled by fatty tissue and tissue fluid. It contains the superficial or cutaneous branches of nerves, arteries, veins, and lymphatics (NAVL) of the skin.

DEEP FASCIAE

The deep fasciae include various membranes made of consolidated or dense FCT. A deep fascia envelops the entire body as the third envelope. This third envelope is known as the investing deep fascia. It is beneath the skin and subcutaneous layer. Deep fasciae also include the envelopes of the muscles and other organs. Around individual organs (for example, the kidney), it is called a capsule.

Another form of deep fascia is found in the collections of loose areolar FCT and fat that are found as filling among the organs. Similar deep fasciae attach organs to the body wall.