| Fascia | |
|---|---|
 Therectus sheath (extensive vertical darker gray at left), an example of a fascia | |
| Details | |
| Precursor | Mesenchyme |
| Identifiers | |
| Latin | fascia |
| MeSH | D005205 |
| TA98 | A04.0.00.031 |
| TA2 | 2015 |
| FMA | 78550 |
| Anatomical terminology | |
Afascia (/ˈfæʃ(i)ə/;pl.:fasciae/ˈfæʃii/ orfascias;[1] adjectivefascial; from Latin fascia 'band') is a generic term formacroscopicmembranous bodily structures.[2]: 42 Fasciae are classified assuperficial,visceral ordeep, and further designated according to their anatomical location.[3]
The knowledge of fascial structures is essential insurgery, as they create borders for infectious processes (for examplePsoas abscess) and haematoma. An increase in pressure may result in acompartment syndrome, where a promptfasciotomy may be necessary. For this reason, profound descriptions of fascial structures are available in anatomical literature from the 19th century.
Fasciae were traditionally thought of as passive structures that transmit mechanical tension generated by muscular activities or external forces throughout the body. An important function of muscle fasciae is to reduce friction of muscular force. In doing so, fasciae provide a supportive and movable wrapping for nerves and blood vessels as they pass through and between muscles.[4]
In the tradition of medical dissections it has been common practice to carefully clean muscles and other organs from their surrounding fasciae in order to study their detailed topography and function. However, this practice tends to ignore that many muscle fibers insert into their fascial envelopes and that the function of many organs is significantly altered when their related fasciae are removed.[5] This insight contributed to several modern biomechanical concepts of the human body, in which fascial tissues take over important stabilizing and connecting functions, by distributing tensional forces across several joints in a network-like manner similar to the architectural concept oftensegrity.[6]Starting in 2018 this concept of the fascial tissue serving as a body-wide tensional support system has been successfully expressed as an educational model with theFascial Net Plastination Project.
Fascial tissues – particularly those with tendinous or aponeurotic properties – are also able to store and release elastic potential energy.
Beyond storing and releasing elastic energy, fascial tissues contribute to proprioception and motor control through dense innervation with mechanoreceptors and nociceptors. Recent biomechanical studies also emphasize the role of fascial networks in distributing strain across multiple joints. This is an idea often framed as a body-wide tensegrity system, so that fascia participates dynamically in coordinated movement and postural stability.[7][8][failed verification]
Afascial compartment is a section within the body that containsmuscles andnerves and is surrounded by fascia. In thehuman body, thelimbs can each be divided into two segments. Theupper limb can be divided into thearm and theforearm; their sectional compartments are thefascial compartments of the arm and thefascial compartments of the forearm, which both contain an anterior and a posterior compartment. The lower limbs can also be divided into two segments: theleg and thethigh; those contain thefascial compartments of the leg and thefascial compartments of the thigh respectively.
Fascia itself becomes clinically important when it loses stiffness, becomes too stiff, or has decreased shearing ability.[9] Fascial dysfunction has been implicated in a range of musculoskeletal pain syndromes, including myofascial pain and some cases of chronic low back pain, where altered fascial gliding or adhesions may contribute to symptoms. Surgical disruption of fascial planes can produce postoperative adhesions and functional limitations. Rehabilitation approaches such as targeted physical therapy and myofascial release aim to restore fascial mobility and reduce pain, though high-quality randomized trials assessing long-term efficacy are limited.[10][11]When inflammatoryfasciitis or trauma causesfibrosis and adhesions, fascial tissue fails to differentiate the adjacent structures effectively. This can happen after surgery, where the fascia has been incised and healing includes ascar that traverses the surrounding structures.
TheFascial Net Plastination Project (FNPP) is an anatomical research initiative spearheaded by fascia researcherRobert Schleip. The project aims to enhance the study of fascia through the technique ofplastination. Led by an international team of fascia experts and anatomists, the FNPP resulted in the creation of a full-body fascia plastinate known asFR:EIA (Fascia Revealed: Educating Interconnected Anatomy).[12] This plastinate provides a detailed view of the human fascial network, allowing for a better understanding of its structure and function as an interconnected tissue throughout the body.
FR:EIA was unveiled at the 2021Fascia Research Congress and is currently exhibited at theBody Worlds exhibition in Berlin. This project represents a significant contribution to the visualization of fascia and has the potential to influence future research in fields such as medicine, physical therapy, and movement science.[12][13]
There exists some controversy about what structures are considered "fascia" and how they should be classified.[14][15]
The current version of the International Federation of Associations of Anatomists divides into:[14]
Two former, rather commonly used systems are:
| NA 1983 | TA 1997 | Description | Example |
|---|---|---|---|
| Superficial fascia | (not considered fascia in this system) | This is found in thesubcutis in most regions of the body, blending with the reticular layer of thedermis.[16] | Fascia of Scarpa |
| Deep fascia | Fascia of muscles | This is thedense fibrous connective tissue that interpenetrates and surrounds the muscles, bones, nerves and blood vessels of the body. | Transverse fascia |
| Visceral fascia | Visceral fascia, parietal fascia | This suspends the organs within their cavities and wraps them in layers of connective tissuemembranes. | Pericardium |
Superficial fascia is the lowermost layer of theskin in nearly all of the regions of thebody, that blends with thereticular dermis layer.[17] It is present on theface, over the upper portion of thesternocleidomastoid, at thenape of theneck and overlying thebreastbone.[18] It consists mainly of looseareolar and fattyadiposeconnective tissue and is the layer that primarily determines the shape of a body.[medical citation needed] In addition to itssubcutaneous presence, superficial fascia surroundsorgans,glands andneurovascular bundles, and fills otherwise empty space at many other locations. It serves as a storage medium offat andwater; as a passageway forlymph,nerve andblood vessels; and as a protective padding to cushion and insulate.[19]
Superficial fascia is present, but does not contain fat, in theeyelid,ear,scrotum,penis andclitoris.[20]
Due to itsviscoelastic properties, superficial fascia can stretch to accommodate the deposition of adipose that accompanies both ordinary andprenatal weight gain. Afterpregnancy and weight loss, the superficial fascia slowly reverts to its original level of tension.
Visceral fascia (also calledsubserous fascia) suspends the organs within their cavities and wraps them in layers of connective tissuemembranes. Each of the organs is covered in a double layer of fascia; these layers are separated by a thinserous membrane.
Visceral fascia is less extensible than superficial fascia. Due to its suspensory role for the organs, it needs to maintain its tone rather consistently. If it is too lax, it contributes to organprolapse, yet if it ishypertonic, it restricts proper organmotility.[22]
Deep fascia is a layer ofdense fibrous connective tissue which surrounds individualmuscles and divides groups of muscles intofascial compartments. This fascia has a high density ofelastin fibre that determines itsextensibility or resilience.[23] Deep fascia was originally considered to be essentially avascular but later investigations have confirmed a rich presence of thin blood vessels.[24] Deep fascia is also richly supplied withsensory receptors.[25] Histologically, fascia is composed predominantly of type I collagen fibers with variable amounts of elastin, which together determine tensile strength and extensibility. Fibroblasts are the principal resident cells, and fascial tissue contains vascular elements (particularly in deep fascia), immune cells such as macrophages and mast cells, and a dense array of sensory nerve endings; these features enable fascia to participate in repair, inflammation, and nociception.[26][27] Examples of deep fascia arefascia lata,fascia cruris,brachial fascia,plantar fascia,thoracolumbar fascia andBuck's fascia.
