Fascia

Fasciae are connective tissues found below the skin.

Gross anatomy

A consensus terminology on the components of fascia is elusive ¹. Many anatomy authors in the English language separate the fascia into superficial and deep layers.

Superficial fascia refers to the loose connective tissue layer below the dermis. In British-American nomenclature, such as in Gray's Anatomy, this tissue includes two components, one of mostly adipose tissue and a deeper membranous layer of fibroareolar tissue that may also include vessels, nerves, and even certain cutaneous muscles (e.g. platysma). For example, in the anterior abdominal wall, the former is called Camper fascia and the latter is Scarpa fascia. The Scarpa fascia is continuous with Colles fascia in the perineum.

Deep fascia refers to the denser fibrous connective tissue that envelops the musculature. The deep fascia consists of a peripheral investing layer and a deeper intermuscular network of muscle sheaths and septa that is continuous with the epimysium. Examples of the former include the transversalis fascia in the anterior abdominal wall, the fascia lata in the thigh, and the plantar fascia in the foot. 

Because of differences with non-English authorities, the Terminologia Anatomica, the international standard published in 1998, abandoned "superficial fascia" in favor of "subcutaneous tissue" or "hypodermis"². This terminology is usually consistent with usage by surgeons, such that "fascia" alone refers to the deep fascia ²³. Radiologists may choose to follow a similarly simplified terminology because the deep membranous layer of the superficial fascia cannot be adequately resolved on current imaging ^2,33,4.

Some authorities define a third category, the visceral fascia, as the connective tissue investing/suspending visceral structures and lining body cavities². However, these are more commonly known separately by their specialized names, such as the peritoneum, omentum, pericardium, and meninges.

Related pathology

• necrotizing fasciitis
• Fournier gangrene
• plantar fasciitis
• retroperitoneal fasciitis
• nodular fasciitis