Researchers disagree on a single comprehensive definition of "fascia." Despite scientific uncertainty, medical texts agree that fascia covers every structure of the body, creating structural continuity that confers form and function to all tissues and organs. Fascial tissue exhibits ubiquitous distribution throughout the body. This tissue can wrap, interpenetrate, support, and constitute blood vessels, bone tissue, meningeal tissue, organs, and skeletal muscles. Fascia forms interdependent layers from the skin to the periosteum, creating a 3-dimensional mechano-metabolic structure.

Several major scholarly groups have proposed definitions of fascia. The Federative Committee on Anatomical Terminology (FCAT, 1989) distinguished between the superficial fascia—a loose subcutaneous tissue layer—and the deep fascia located underneath. The Federative International Programme on Anatomical Terminologies (FIPAT, 2011) described fascia as any dissectible connective tissue beneath the skin that attaches, encloses, and separates muscles and organs. This definition emphasized fascia as connective tissue that divides, supports, and structures bodily components, excluding only the epidermis.

In 2014, the Fascia Nomenclature Committee, part of the Fascia Research Society, proposed the broader concept of a fascial system as a continuous 3-dimensional network of connective tissues, including fasciae, tendons, ligaments, membranes, and additional structures, that integrates all body systems. In 2013, the FORCE (Foundation of Osteopathic Research and Clinical Endorsement) group similarly expanded on this concept, describing fascia as a dynamic continuum linking tissues, fluids, and organs that transmits mechanical and metabolic information throughout the body (see Image. Structural Elements Identified as Connective Tissue). Collectively, these definitions portray fascia as an uninterrupted connective network derived from mesodermal tissues, essential for maintaining structural and functional unity.

Disclosure: Bruno Bordoni declares no relevant financial relationships with ineligible companies.

Disclosure: Navid Mahabadi declares no relevant financial relationships with ineligible companies.

Disclosure: Felix Jozsa declares no relevant financial relationships with ineligible companies.

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