
A fascia (; : fasciae or fascias;
adjective fascial; ) is a generic term for
macroscopic
The macroscopic scale is the length scale on which objects or phenomena are large enough to be visible with the naked eye, without magnifying optical instruments. It is the opposite of microscopic.
Overview
When applied to physical phenome ...
membranous bodily structures.
Fasciae are classified as
superficial
Superficial may refer to:
*Superficial anatomy, is the study of the external features of the body
*Superficiality, the discourses in philosophy regarding social relation
* Superficial charm, the tendency to be smooth, engaging, charming, slick and ...
,
visceral
In a multicellular organism, an organ is a collection of Tissue (biology), tissues joined in a structural unit to serve a common function. In the biological organization, hierarchy of life, an organ lies between Tissue (biology), tissue and an o ...
or
deep
Deep or The Deep may refer to:
Places United States
* Deep Creek (Appomattox River tributary), Virginia
* Deep Creek (Great Salt Lake), Idaho and Utah
* Deep Creek (Mahantango Creek tributary), Pennsylvania
* Deep Creek (Mojave River tributary ...
, and further designated according to their anatomical location.
The knowledge of fascial structures is essential in
surgery
Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...
, as they create borders for infectious processes (for example
Psoas abscess) and haematoma. An increase in pressure may result in a
compartment syndrome
Compartment syndrome is a serious medical condition in which increased pressure within a Fascial compartment, body compartment compromises blood flow and tissue function, potentially leading to permanent damage if not promptly treated. There are ...
, where a prompt
fasciotomy may be necessary. For this reason, profound descriptions of fascial structures are available in anatomical literature from the 19th century.
Function
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.
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.
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 of tensegrity.
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 the
Fascial Net Plastination Project.
Fascial tissues – particularly those with tendinous or aponeurotic properties – are also able to store and release elastic potential energy.
Anatomical compartments
A
fascial compartment
A fascial compartment is a section within the body that contains Skeletal muscle, muscles and nerves and is surrounded by deep fascia. In the human body, the Limb (anatomy), limbs can each be divided into two segments – the upper limb can be di ...
is a section within the body that contains
muscles
Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
and
nerves and is surrounded by fascia. In the
human body
The human body is the entire structure of a Human, human being. It is composed of many different types of Cell (biology), cells that together create Tissue (biology), tissues and subsequently Organ (biology), organs and then Organ system, org ...
, the
limbs can each be divided into two segments: The
upper limb
The upper Limb (anatomy), limbs or upper extremities are the forelimbs of an upright posture, upright-postured tetrapod vertebrate, extending from the scapulae and clavicles down to and including the digit (anatomy), digits, including all the musc ...
can be divided into the
arm and the
forearm
The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is used to describe the entire appendage of the upper limb, but which in anatomy, techn ...
and the sectional compartments of both of these – the
fascial compartments of the arm and the
fascial compartments of the forearm contain an anterior and a posterior compartment. The lower limbs can be divided into two segments – the
leg
A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element cap ...
and the
thigh
In anatomy, the thigh is the area between the hip (pelvis) and the knee. Anatomically, it is part of the lower limb.
The single bone in the thigh is called the femur. This bone is very thick and strong (due to the high proportion of bone tissu ...
– and these contain the
fascial compartments of the leg and the
fascial compartments of the thigh.
File:Plastinated Human Thigh.jpg, Photo of cross-sectional slice from a plastinated human thigh.
File:Schematic drawing of a transverse section of the thigh illustrating its fascial anatomy.webp, Schematic drawing of a transverse section of the thigh illustrating its fascial anatomy.
Clinical significance
Fascia itself becomes clinically important when it loses stiffness, becomes too stiff, or has decreased shearing ability. When inflammatory
fasciitis
Fasciitis is an inflammation of the fascia, which is the connective tissue surrounding muscles, blood vessels and nerves.
In particular, it often involves one of the following diseases:
* Necrotizing fasciitis
* Plantar fasciitis
* Ischemic fasc ...
or trauma causes
fibrosis 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 a
scar
A scar (or scar tissue) is an area of fibrosis, fibrous tissue that replaces normal skin after an injury. Scars result from the biological process of wound repair in the skin, as well as in other Organ (anatomy), organs, and biological tissue, t ...
that traverses the surrounding structures.
Fascial Net Plastination Project
The
Fascial Net Plastination Project (FNPP) is an anatomical research initiative spearheaded by fascia researcher
Robert Schleip. The project aims to enhance the study of fascia through the technique of
plastination. Led by an international team of fascia experts and anatomists, the FNPP resulted in the creation of a full-body fascia plastinate known as FR:EIA (Fascia Revealed: Educating Interconnected Anatomy).
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 2021
Fascia Research Congress and is currently exhibited at the
Body 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.
Terminology
There exists some controversy about what structures are considered "fascia" and how they should be classified.
The current version of the International Federation of Associations of Anatomists divides into:
* Fascia craniocervicalis
* Fascia trunci
** Fascia parietalis
** Fascia extraserosalis
** Fascia visceralis
* Fasciae membrorum
* Fasciae musculorum
** Fascia investiens
** Fascia propria musculi
Previous terminology
Two former, rather commonly used systems are:
* The one specified in the 1983 edition of
Nomina Anatomica (NA 1983)
* The one specified in the 1997 edition of
Terminologia Anatomica (TA 1997)
Superficial
Superficial fascia is the lowermost layer of the
skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other animal coverings, such as the arthropod exoskeleton, have different ...
in nearly all of the regions of the
body, that blends with the
reticular dermis layer. It is present on the
face
The face is the front of the head that features the eyes, nose and mouth, and through which animals express many of their emotions. The face is crucial for human identity, and damage such as scarring or developmental deformities may affect th ...
, over the upper portion of the
sternocleidomastoid
The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles. The primary actions of the muscle are rotation of the head to the opposite side and flexion of the neck. The sternocleidomastoid is innervated by the acces ...
, at the
nape
The nape is the back of the neck. In technical anatomical/medical terminology, the nape is also called the nucha (from the Medieval Latin rendering of the Arabic , ). The corresponding adjective is ''nuchal'', as in the term ''nuchal rigidity'' ...
of the
neck
The neck is the part of the body in many vertebrates that connects the head to the torso. It supports the weight of the head and protects the nerves that transmit sensory and motor information between the brain and the rest of the body. Addition ...
and overlying the
breastbone. It consists mainly of loose
areolar and fatty
adipose
Adipose tissue (also known as body fat or simply fat) is a loose connective tissue composed mostly of adipocytes. It also contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, Blood vessel, vascular endothel ...
connective tissue
Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesod ...
and is the layer that primarily determines the shape of a body. In addition to its
subcutaneous presence, superficial fascia surrounds
organs,
glands
A gland is a Cell (biology), cell or an Organ (biology), organ in an animal's body that produces and secretes different substances that the organism needs, either into the bloodstream or into a body cavity or outer surface. A gland may also funct ...
and
neurovascular bundles, and fills otherwise empty space at many other locations. It serves as a storage medium of
fat
In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food.
The term often refers specif ...
and
water
Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...
; as a passageway for
lymph
Lymph () is the fluid that flows through the lymphatic system, a system composed of lymph vessels (channels) and intervening lymph nodes whose function, like the venous system, is to return fluid from the tissues to be recirculated. At the ori ...
,
nerve
A nerve is an enclosed, cable-like bundle of nerve fibers (called axons). Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the Electrochemistry, electrochemical nerv ...
and
blood vessels
Blood vessels are the tubular structures of a circulatory system that transport blood throughout many animals’ bodies. Blood vessels transport blood cells, nutrients, and oxygen to most of the tissues of a body. They also take waste an ...
; and as a protective padding to cushion and insulate.
Superficial fascia is present, but does not contain fat, in the
eyelid
An eyelid ( ) is a thin fold of skin that covers and protects an eye. The levator palpebrae superioris muscle retracts the eyelid, exposing the cornea to the outside, giving vision. This can be either voluntarily or involuntarily. "Palpebral ...
,
ear,
scrotum
In most terrestrial mammals, the scrotum (: scrotums or scrota; possibly from Latin ''scortum'', meaning "hide" or "skin") or scrotal sac is a part of the external male genitalia located at the base of the penis. It consists of a sac of skin ...
,
penis
A penis (; : penises or penes) is a sex organ through which male and hermaphrodite animals expel semen during copulation (zoology), copulation, and through which male placental mammals and marsupials also Urination, urinate.
The term ''pen ...
and
clitoris
In amniotes, the clitoris ( or ; : clitorises or clitorides) is a female sex organ. In humans, it is the vulva's most erogenous zone, erogenous area and generally the primary anatomical source of female Human sexuality, sexual pleasure. Th ...
.
Due to its
viscoelastic
In materials science and continuum mechanics, viscoelasticity is the property of materials that exhibit both Viscosity, viscous and Elasticity (physics), elastic characteristics when undergoing deformation (engineering), deformation. Viscous mate ...
properties, superficial fascia can stretch to accommodate the deposition of adipose that accompanies both ordinary and
prenatal
Prenatal development () involves the embryonic development, development of the embryo and of the fetus during a viviparity, viviparous animal's gestation. Prenatal development starts with fertilization, in the germinal stage of embryonic develop ...
weight gain. After
pregnancy
Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins.
Conception (biology), Conception usually occurs ...
and weight loss, the superficial fascia slowly reverts to its original level of tension.
Visceral
Visceral fascia (also called subserous fascia) suspends the organs within their cavities and wraps them in layers of connective tissue
membranes. Each of the organs is covered in a double layer of fascia; these layers are separated by a thin
serous membrane
The serous membrane (or serosa) is a smooth epithelial membrane of mesothelium lining the contents and inner walls of body cavity, body cavities, which secrete serous fluid to allow lubricated sliding (motion), sliding movements between opposing ...
.
* The outermost wall of the organ is known as the
parietal layer
* The skin of the organ is known as the
viscera
In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to a ...
l layer. The organs have specialized names for their visceral fasciae. In the brain, they are known as
meninges
In anatomy, the meninges (; meninx ; ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in the subarachnoid spac ...
; in the heart they are known as
pericardia; in the lungs, they are known as
pleurae
The pleurae (: pleura) are the two flattened closed sacs filled with pleural fluid, each ensheathing each lung and lining their surrounding tissues, locally appearing as two opposing layers of serous membrane separating the lungs from the media ...
; and in the abdomen, they are known as
peritonea.
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 organ
prolapse
In medicine, prolapse is a condition in which organ (anatomy), organs fall down or slip out of place. It is used for organs protruding through the vagina, rectum, or for the misalignment of the valves of the heart. A spinal disc herniation is al ...
, yet if it is
hypertonic, it restricts proper organ
motility
Motility is the ability of an organism to move independently using metabolism, metabolic energy. This biological concept encompasses movement at various levels, from whole organisms to cells and subcellular components.
Motility is observed in ...
.
Deep
Deep fascia is a layer of
dense fibrous connective tissue which surrounds individual
muscle
Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
s and divides groups of muscles into
fascial compartment
A fascial compartment is a section within the body that contains Skeletal muscle, muscles and nerves and is surrounded by deep fascia. In the human body, the Limb (anatomy), limbs can each be divided into two segments – the upper limb can be di ...
s.
This fascia has a high density of
elastin
Elastin is a protein encoded by the ''ELN'' gene in humans and several other animals. Elastin is a key component in the extracellular matrix of gnathostomes (jawed vertebrates). It is highly Elasticity (physics), elastic and present in connective ...
fibre that determines its
extensibility
Extensibility is a software engineering and systems design principle that provides for future growth. Extensibility is a measure of the ability to extend a system and the level of effort required to implement the extension. Extensions can be t ...
or resilience. Deep fascia was originally considered to be essentially avascular but later investigations have confirmed a rich presence of thin blood vessels.
Deep fascia is also richly supplied with
sensory receptor
Sensory neurons, also known as afferent neurons, are neurons in the nervous system, that convert a specific type of stimulus, via their receptors, into action potentials or graded receptor potentials. This process is called sensory transduc ...
s.
Examples of deep fascia are
fascia lata,
fascia cruris,
brachial fascia,
plantar fascia
The plantar fascia or plantar aponeurosis is the thick connective tissue aponeurosis which supports the Arches of the foot, arch on the bottom (plantar side) of the foot. Recent studies suggest that the plantar fascia is actually an aponeurosis r ...
,
thoracolumbar fascia
The thoracolumbar fascia (lumbodorsal fascia or thoracodorsal fascia) is a complex, multilayer arrangement of fascial and aponeurotic layers forming a separation between the paraspinal muscles on one side, and the muscles of the posterior abdomina ...
and
Buck's fascia
Buck's fascia (deep fascia of the penis, Gallaudet's fascia or fascia of the penis) is a layer of deep fascia covering the three erectile bodies of the penis.
Structure
Buck's fascia is continuous with the external spermatic fascia in the scro ...
.
See also
*
Clavipectoral fascia
*
Endothoracic fascia
*
Extracellular matrix
In biology, the extracellular matrix (ECM), also called intercellular matrix (ICM), is a network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide structural and bio ...
*
Interstitial cell
*
Pectoral fascia
*
Thoracolumbar fascia
The thoracolumbar fascia (lumbodorsal fascia or thoracodorsal fascia) is a complex, multilayer arrangement of fascial and aponeurotic layers forming a separation between the paraspinal muscles on one side, and the muscles of the posterior abdomina ...
*
Fascia (architecture)
Fascia () is an architectural term for a vertical frieze or band under a roof edge, or which forms the outer surface of a cornice, visible to an observer.
Typically consisting of a wooden board, unplasticized PVC (uPVC), or non-corrosive shee ...
References
External links
Fascia Research*
{{Authority control
Connective tissue