Corpus: Fascia
1. Definition
Fascia refers to a sheet-like layer of collagenous connective tissue that can surround individual muscels, muscle groups, organs, or entire sections of the body.
2. Nomenclature
According to more recent nomenclature, the concept of fascia is much broader and includes all connective tissues with a high proportion of collagen fibers, including joint and organ capsules, aponeuroses, muscle septa, ligaments, tendons and retinacula, in addition to the "traditional" anatomical fasciae (e.g., thoracolumbar fascia).
3. Classification
There are three layers of fascia, superficial, visceral and deep fascia.
4. Histology
The fascia is mostly made up of tightly woven, mesh-like collagen fibers and elastin. On the inside of the fascia, there is a thin layer of loose connective tissue, known as the epimysium. At the ends of a muscle, the fascia merges with the muscle's tendon.
5. Physiology
Unlike muscle tissue itself, fasciae are passive structures that give the muscle form and firmness. They serve as a counterbalance, preventing the muscle fibers from losing their morphological cohesion during function. Furthermore, they serve to delineate muscles from each other, thus preventing closely adjacent muscles from affecting each other during contraction.
In some cases, fasciae serve as the origin or insertion point of muscles.
6. Wound Healing
Recent research suggests that fasciae play an important role in the healing of deep wounds. In mammals, deep injuries prompt a rapid migration of fibroblasts from the subcutaneous fascial layer into the wound area. This process drags parts of the extracellular matrix, as well as smaller blood vessels and nerves, like a "patch." Blocking this process in animal experiments led to the development of chronic wounds.
7. Examples
The superficial layers of the fasciae from various anatomical regions together form the general body fascia.