Anatomical terminology uses many unique terms, suffixes, and prefixes deriving from Ancient Greek and Latin. These terms can be confusing to those unfamiliar with them, but can be more precise, reducing ambiguity and errors. Also, since these anatomical terms are not used in everyday conversation, their meanings are less likely to change, and less likely to be misinterpreted.
To illustrate how inexact day-to-day language can be: a scar "above the wrist" could be located on the forearm two or three inches away from the hand or at the base of the hand; and could be on the palm-side or back-side of the arm. By using precise anatomical terminology such ambiguity is eliminated.
An international standard for anatomical terminology, Terminologia Anatomica has been created.
Anatomical terminology has quite regular morphology, the same prefixes and suffixes are used to add meanings to different roots. The root of a term often refers to an organ or tissue. For example, the Latin names of structures such as musculus biceps brachii can be split up and refer to, musculus for muscle, biceps for "two-headed", brachii as in the brachial region of the arm. The first word describes what is being spoken about, the second describes it, and the third points to location.
When describing the position of anatomical structures, structures may be described according to the anatomical landmark they are near. These landmarks may include structures, such as the umbilicus or sternum, or anatomical lines, such as the midclavicular line from the centre of the clavicle. The cephalon or cephalic region refers to the head. This area is further differentiated into the cranium (skull), facies (face), frons (forehead), oculus (eye area), auris (ear), bucca (cheek), nasus (nose), oris (mouth), and mentum (chin). The neck area is called the cervix or cervical region. Examples of structures named according to this include the frontalis muscle, submental lymph nodes, buccal membrane and orbicularis oculi muscle.
Sometimes, unique terminology is used to reduce confusion in different parts of the body. For example, different terms are used when it comes to the skull in compliance with its embryonic origin and its tilted position compared to in other animals. Here, Rostral refers to proximity to the front of the nose, and is particularly used when describing the skull.:4 Similarly, different terminology is often used in the arms, in part to reduce ambiguity as to what the "front", "back", "inner" and "outer" surfaces are. For this reason, the terms below are used:
Other terms are also used to describe the movement and actions of the hands and feet, and other structures such as the eye.
International morphological terminology is used by the colleges of medicine and dentistry and other areas of the health sciences. It facilitates communication and exchanges between scientists from different countries of the world and it is used daily in the fields of research, teaching and medical care. The international morphological terminology refers to morphological sciences as a biological sciences' branch. In this field, the form and structure are examined as well as the changes or developments in the organism. It is descriptive and functional. Basically, it covers the gross anatomy and the microscopic (histology and cytology) of living beings. It involves both development anatomy (embryology) and the anatomy of the adult. It also includes comparative anatomy between different species. The vocabulary is extensive, varied and complex, and requires a systematic presentation.
Within the international field, a group of experts reviews, analyzes and discusses the morphological terms of the structures of the human body, forming today's Terminology Committee (FICAT) from the International Federation of Associations of Anatomists (IFAA). It deals with the anatomical, histological and embryologic terminology. In the Latin American field, there are meetings called Iberian Latin American Symposium Terminology (SILAT), where a group of experts of the Pan American Association of Anatomy (PAA) that speak Spanish and Portuguese, disseminates and studies the international morphological terminology.
The current international standard for human anatomical terminology is based on the Terminologia Anatomica (TA). It was developed by the Federative Committee on Anatomical Terminology (FCAT) and the International Federation of Associations of Anatomists (IFAA) and was released in 1998. It supersedes the previous standard, Nomina Anatomica. Terminologia Anatomica contains terminology for about 7500 human gross (macroscopic) anatomical structures. For microanatomy, known as histology, a similar standard exists in Terminologia Histologica, and for embryology, the study of development, a standard exists in Terminologia Embryologica. These standards specify generally accepted names that can be used to refer to histological and embryological structures in journal articles, textbooks, and other areas. As of September 2016, two sections of the Terminologia Anatomica, including central nervous system and peripheral nervous system, were merged to form the Terminologia Neuroanatomica.
Recently, the Terminologia Anatomica has been perceived with a considerable criticism regarding its content including coverage, grammar and spelling mistakes, inconsistencies, and errors.
Anatomical terminology is often chosen to highlight the relative location of body structures. For instance, an anatomist might describe one band of tissue as "inferior to" another or a physician might describe a tumor as "superficial to" a deeper body structure.
Anatomical terms used to describe location are based on a body positioned in what is called the standard anatomical position. This position is one in which a person is standing, feet apace, with palms forward and thumbs facing outwards. Just as maps are normally oriented with north at the top, the standard body "map," or anatomical position, is that of the body standing upright, with the feet at shoulder width and parallel, toes forward. The upper limbs are held out to each side, and the palms of the hands face forward.
Using the standard anatomical position reduces confusion. It means that regardless of the position of a body, the position of structures within it can be described without ambiguity.
In terms of anatomy, the body is divided into regions. In the front, the trunk is referred to as the "thorax" and "abdomen". The back as a general area is the dorsum or dorsal area, and the lower back is the lumbus or lumbar region. The shoulder blades are the scapular area and the breastbone is the sternal region. The abdominal area is the region between the chest and the pelvis. The breast is also called the mammary region, the armpit as the axilla and axillary, and the navel as the umbilicus and umbilical. The pelvis is the lower torso, between the abdomen and the thighs. The groin, where the thigh joins the trunk, are the inguen and inguinal area.
The entire arm is referred to as the brachium and brachial, the front of the elbow as the antecubitis and antecubital, the back of the elbow as the olecranon or olecranal, the forearm as the antebrachium and antebrachial, the wrist as the carpus and carpal area, the hand as the manus and manual, the palm as the palma and palmar, the thumb as the pollex, and the fingers as the digits, phalanges, and phalangeal. The buttocks are the gluteus or gluteal region and the pubic area is the pubis.
Anatomists divide the lower limb into the thigh (the part of the limb between the hip and the knee) and the leg (which refers only to the area of the limb between the knee and the ankle). The thigh is the femur and the femoral region. The kneecap is the patella and patellar while the back of the knee is the popliteus and popliteal area. The leg (between the knee and the ankle) is the crus and crural area, the lateral aspect of the leg is the peroneal area, and the calf is the sura and sural region. The ankle is the tarsus and tarsal, and the heel is the calcaneus or calcaneal. The foot is the pes and pedal region, and the sole of the foot the planta and plantar. As with the fingers, the toes are also called the digits, phalanges, and phalangeal area. The big toe is referred to as the hallux.
To promote clear communication, for instance about the location of a patient’s abdominal pain or a suspicious mass, the abdominal cavity can be divided into either nine regions or four quadrants.
The abdomen may be divided into four quadrants, more commonly used in medicine, subdivides the cavity with one horizontal and one vertical line that intersect at the patient’s umbilicus (navel). The right upper quadrant (RUQ) includes the lower right ribs, right side of the liver, and right side of the transverse colon. The left upper quadrant (LUQ) includes the lower left ribs, stomach, spleen, and upper left area of the transverse colon. The right lower quadrant (RLQ) includes the right half of the small intestines, ascending colon, right pelvic bone and upper right area of the bladder. The left lower quadrant (LLQ) contains the left half of the small intestine and left pelvic bone.
The more detailed regional approach subdivides the cavity into nine regions, with two vertical and two horizontal lines drawn according to landmark structures. The vertical; or midclavicular lines, are drawn as if dropped from the midpoint of each clavicle. The superior horizontal line is the subcostal line, drawn immediately inferior to the ribs. The inferior horizontal line is called the intertubercular line, and is to cross the iliac tubercles, found at the superior aspect of the pelvis. The upper right square is the right hypochondriac region and contains the base of the right ribs. The upper left square is the left hypochondriac region and contains the base of the left ribs.
The epigastric region is the upper central square and contains the bottom edge of the liver as well as the upper areas of the stomach. The diaphragm curves like an upside down U over these three regions. The central right region is called the right lumbar region and contains the ascending colon and the right edge of the small intestines. The central square contains the transverse colon and the upper regions of the small intestines. The left lumbar region contains the left edge of the transverse colon and the left edge of the small intestine. The lower right square is the right iliac region and contains the right pelvic bones and the ascending colon. The lower left square is the left iliac region and contains the left pelvic bone and the lower left regions of the small intestine. The lower central square contains the bottom of the pubic bones, upper regions of the bladder and the lower region of the small intestine.
When anatomists refer to the right and left of the body, it is in reference to the right and left of the subject, not the right and left of the observer. When observing a body in the anatomical position, the left of the body is on the observer’s right, and vice versa.
These standardized terms avoid confusion. Examples of terms include::4
Each locational term above can define the direction of a vector, and pairs of them can define axes, that is, lines of orientation. For example, blood can be said to flow in a proximal or distal direction, and anteroposterior, mediolateral, and inferosuperior axes are lines along which the body extends, like the X, Y, and Z axes of a Cartesian coordinate system. An axis can be projected to a corresponding plane.
Anatomy is often described in planes, referring to two-dimensional sections of the body. A section is a two-dimensional surface of a three-dimensional structure that has been cut. A plane is an imaginary two-dimensional surface that passes through the body. Three planes are commonly referred to in anatomy and medicine::4
Anatomical terms may be used to describe the functional state of an organ:
The term anatomical variation is used to refer to a difference in anatomical structures that is not regarded as a disease. Many structures vary slightly between people, for example muscles that attach in slightly different places. For example, the presence or absence of the palmaris longus tendon. Anatomical variation is unlike congenital anomalies, which are considered a disorder.
Joints, especially synovial joints allow the body a tremendous range of movements. Each movement at a synovial joint results from the contraction or relaxation of the muscles that are attached to the bones on either side of the articulation. The type of movement that can be produced at a synovial joint is determined by its structural type.
Movement types are generally paired, with one being the opposite of the other. Body movements are always described in relation to the anatomical position of the body: upright stance, with upper limbs to the side of body and palms facing forward.
Terms describing motion in general include:
These terms refer to movements that are regarded as unique to the hands and feet::590–7
Muscle action that moves the axial skeleton work over a joint with an origin and insertion of the muscle on respective side. The insertion is on the bone deemed to move towards the origin during muscle contraction. Muscles are often present that engage in several actions of the joint; able to perform for example both flexion and extension of the forearm as in the biceps and triceps respectively. This is not only to be able to revert actions of muscles, but also brings on stability of the actions though muscle coactivation.
The muscle performing an action is the agonist, while the muscle which contraction brings about an opposite action is the antagonist. For example, an extension of the lower arm is performed by the triceps as the agonist and the biceps as the antagonist (which contraction will perform flexion over the same joint). Muscles that work together to perform the same action are called synergists. In the above example synergists to the biceps can be the brachioradialis and the brachialis muscle.
The gross anatomy of a muscle is the most important indicator of its role in the body. One particularly important aspect of gross anatomy of muscles is pennation or lack thereof. In most muscles, all the fibers are oriented in the same direction, running in a line from the origin to the insertion. In pennate muscles, the individual fibers are oriented at an angle relative to the line of action, attaching to the origin and insertion tendons at each end. Because the contracting fibers are pulling at an angle to the overall action of the muscle, the change in length is smaller, but this same orientation allows for more fibers (thus more force) in a muscle of a given size. Pennate muscles are usually found where their length change is less important than maximum force, such as the rectus femoris.
Skeletal muscle is arranged in discrete muscles, an example of which is the biceps brachii. The tough, fibrous epimysium of skeletal muscle is both connected to and continuous with the tendons. In turn, the tendons connect to the periosteum layer surrounding the bones, permitting the transfer of force from the muscles to the skeleton. Together, these fibrous layers, along with tendons and ligaments, constitute the deep fascia of the body.
Movement is not limited to only synovial joints, although they allow for most freedom. Muscles also run over symphysis, which allow for movement in for example the vertebral column by compression of the intervertebral discs. Additionally, synovial joints can be divided into different types, depending on their axis of movement.
A serous membrane (also referred to as a serosa) is a thin membrane that covers the walls of organs in the thoracic and abdominal cavities. The serous membranes have two layers; parietal and visceral, surrounding a fluid filled space. The visceral layer of the membrane covers the organ (the viscera), and the parietal layer lines the walls of the body cavity (pariet- refers to a cavity wall). Between the parietal and visceral layers is a very thin, fluid-filled serous space, or cavity. For example, the pericardium is the serous cavity which surrounds the heart.
Standard anatomical terms of location deal unambiguously with the anatomy of animals, including humans.
All vertebrates (including humans) have the same basic body plan – they are strictly bilaterally symmetrical in early embryonic stages and largely bilaterally symmetrical in adulthood. That is, they have mirror-image left and right halves if divided down the middle. For these reasons, the basic directional terms can be considered to be those used in vertebrates. By extension, the same terms are used for many other (invertebrate) organisms as well.
While these terms are standardized within specific fields of biology, there are unavoidable, sometimes dramatic, differences between some disciplines. For example, differences in terminology remain a problem that, to some extent, still separates the terminology of human anatomy from that used in the study of various other zoological categories.Anatomical terms of microanatomy
Anatomical terminology is used to describe microanatomical (or histological) structures. This helps describe precisely the structure, layout and position of an object, and minimises ambiguity. An internationally accepted lexicon is Terminologia Histologica.Anatomical terms of neuroanatomy
This article describes anatomical terminology that is used to describe the central and peripheral nervous systems - including the brain, brainstem, spinal cord, and nerves.Decussation
Decussation is used in biological contexts to describe a crossing (Latin: the roman numeral for ten, deca, is an uppercase 'X'). (In Latin anatomical terms the form decussatio is used, e.g. decussatio pyramidum.) Similarly, the anatomical term chiasma is named after the Greek uppercase 'Χ', chi).
In the brain, where nerve fibers obliquely cross from one lateral part to the other, that is to say they cross at a level other than their origin. See for examples Decussation of pyramids and sensory decussation. Decussation describes the point where the nerves cross from one side of the brain to the other, and typically the nerves from the left side of the body decussate to the right side of the brain and the nerves from the right side of the body decussate to the left brain, however depending on the function of the nerves the level of decussation is variable. In neuroanatomy the term chiasma is reserved for the crossing of nerves outside the brain, such as the optic chiasm.
In botanical leaf taxology, the word decussate describes an opposite pattern of leaves which has successive pairs at right angles to each other (i.e. rotated 90 degrees along the stem when viewed from above). In effect, successive pairs of leaves cross each other. Basil is a classic example of a decussate leaf pattern.
In tooth enamel, where bundles of rods cross each other as they travel from the enamel-dentine junction to the outer enamel surface, or near to it.
In taxonomic description where decussate markings or structures occur, names such as decussatus or decussata or otherwise in part containing "decuss..." are common, especially in the specific epithet.Federative International Committee on Anatomical Terminology
The Federative International Committee for Anatomical Terminology (FICAT) is a group of experts who review, analyze and discuss the terms of the morphological structures of the human body. It was created by the International Federation of Associations of Anatomists (IFAA), and was originally known as the Federative Committee on Anatomical Terminology (FCAT).Foundational Model of Anatomy
The Foundational Model of Anatomy Ontology (FMA) is a reference ontology for the domain of anatomy. It is a symbolic representation of the canonical, phenotypic structure of an organism; a spatial-structural ontology of anatomical entities and relations which form the physical organization of an organism at all salient levels of granularity.
FMA is developed and maintained by the Structural Informatics Group at the University of Washington.Medical terminology
Medical terminology is language used to precisely describe the human body including its components, processes, conditions affecting it, and procedures performed upon it. Medical terminology is used in the field of medicine.
Medical terminology has quite regular morphology, the same prefixes and suffixes are used to add meanings to different roots. The root of a term often refers to an organ, tissue, or condition. For example, in the disorder hypertension, the prefix "hyper-" means "high" or "over", and the root word "tension" refers to pressure, so the word "hypertension" refers to abnormally high blood pressure. The roots, prefixes and suffixes are often derived from Greek or Latin, and often quite dissimilar from their English-language variants. This regular morphology means that once a reasonable number of morphemes are learnt it becomes easy to understand very precise terms assembled from these morphemes. A lot of medical language is anatomical terminology, concerning itself with the names of various parts of the body.NeuroLex
NeuroLex is a dynamic lexicon of neuroscience concepts. It is a structured as a semantic wiki, using Semantic MediaWiki. NeuroLex is supported by the Neuroscience Information Framework project.NeuroNames
NeuroNames is an integrated nomenclature for structures in the brain and spinal cord of the four species most studied by neuroscientists: human, macaque, rat and mouse. It offers a standard, controlled vocabulary of common names for structures, which is suitable for unambiguous neuroanatomical indexing of information in digital databases. Terms in the standard vocabulary have been selected for ease of pronunciation, mnemonic value, and frequency of use in recent neuroscientific publications. Structures and their relations to each other are defined in terms of the standard vocabulary. Currently NeuroNames contains standard names, synonyms and definitions of some 2,500 neuroanatomical entities.
The nomenclature is maintained by the University of Washington and is the core component of a tool called "BrainInfo". BrainInfo helps one identify structures in the brain. One can either search by a structure name or locate the structure in a brain atlas and get information such as its location in the classical brain hierarchy, images of the structure, what cells it has, its connections and genes expressed there. Information can be accessed by any of some 16,000 synonyms in eight languages.
NeuroNames is a source vocabulary of the Metathesaurus of the Unified Medical Language System. It is described in depth in the following three scientific articles:
D. M. Bowden & R. F. Martin (March 1995). "NeuroNames Brain Hierarchy". NeuroImage. 2 (1): 63–83. doi:10.1006/nimg.1995.1009. PMID 9410576.
D. M. Bowden & M. F. Dubach (2003). "NeuroNames 2002". Neuroinformatics. 1 (1): 43–59. doi:10.1385/NI:1:1:043. PMID 15055392.
D. M. Bowden; E. Song; J. Kosheleva; M. F. Dubach (2011). "NeuroNames: An Ontology for the BrainInfo Portal to Neuroscience on the Web". Neuroinformatics. 10 (1): 97–114. doi:10.1007/s12021-011-9128-8. PMC 3247656. PMID 21789500.Nomina Anatomica
Nomina Anatomica (NA) was the international standard on human anatomic terminology from 1955 until it was replaced by Terminologia Anatomica in 1998.
In the late nineteenth century some 50,000 terms for various body parts were in use. The same structures were described by different names, depending (among other things) on the anatomist's school and national tradition. Vernacular translations of Latin and Greek, as well as various eponymous terms, were barriers to effective international communication. There was disagreement and confusion among anatomists regarding anatomical terminology.Nomina Anatomica Veterinaria
The Nomina Anatomica Veterinaria (often abbreviated as NAV) is a text prepared by the International Committee on Veterinary Gross Anatomical Nomenclature. It is used as the standard reference for anatomical (zootomical) terminology in the field of Veterinary Science.
The text is continually under revision. The 5th edition is available free of charge from the World Association of Veterinary Anatomists (WAVA) as a PDF file, with last revision in 2017. The 6th edition has not been printed commercially. The 4th edition, published in 1994, was the last commercially printed edition.Retroperitonium
The retroperitoneum or retroperitnium is an anatomical region that includes the peritoneum-covered organs and tissues that make up the posterior wall of the abdominal cavity and the pelvic space - which extends behind to the abdominal cavity. Definitions vary and can also can include the region of the wall of the pelvic basin.
The portion of the retroperitoneum that is posterior wall of the abdomen and superior to the iliac vessels is of importance in gynecological oncology. This is the region where para-aortic and paracaval lymphadenectomies are done. The lateral boundary of the retroperitoneum is defined by the ascending and descending colon. The retroperitoneum can be approached from above by moving the duodenum aside as far as the major renal blood vessels.Standard anatomical position
Because animals can change orientation with respect to their environment, and because appendages (arms, legs, tentacles, etc.) can change position with respect to the main body, it is important that anatomical terms of location refer to the organism when it is in its standard anatomical position.
Thus, all descriptions are with respect to the organism in its standard anatomical position, even when the organism in question has appendages in another position. However, a straight position is assumed when describing the proximo-distal axis. This helps avoid confusion in terminology when referring to the same organism in different postures.Systematized Nomenclature of Medicine
The Systematized Nomenclature of Medicine (SNOMED) is a systematic, computer-processable collection of medical terms, in human and veterinary medicine, to provide codes, terms, synonyms and definitions which cover anatomy, diseases, findings, procedures, microorganisms, substances, etc. It allows a consistent way to index, store, retrieve, and aggregate medical data across specialties and sites of care. Although now international, SNOMED was started in the U.S. by the College of American Pathologists (CAP) in 1973 and revised into the 1990s. In 2002 CAP's SNOMED Reference Terminology (SNOMED RT) was merged with, and expanded by, the National Health Service's Clinical Terms Version 3 (previously known as the Read codes) to produce SNOMED CT.Versions of SNOMED released prior to 2001 were based on a multiaxial, hierarchical classification system. As in any such system, a disease may be located in a body organ (anatomy), which results in a code in a topography axis and may lead to morphological alterations represented by a morphology code.
In 2002 the first release of SNOMED CT adopted a completely different structure. A sub-type hierarchy, supported by defining relationships based on description logic, replaced the axes described in this article. Versions of SNOMED prior to SNOMED CT are planned to be formally deprecated from 2017. Therefore, readers interested in current information about SNOMED are directed to the article on SNOMED CT.Terminologia Anatomica
Terminologia Anatomica (TA) is the international standard on human anatomic terminology. It was developed by the Federative Committee on Anatomical Terminology (FCAT) and the International Federation of Associations of Anatomists (IFAA) and was released in 1998. It supersedes the previous standard, Nomina Anatomica. Terminologia Anatomica contains terminology for about 7500 human gross (macroscopic) anatomical structures. In April 2011, Terminologia Anatomica was published online by the Federative International Programme on Anatomical Terminologies (FIPAT), the successor of FCAT.Terminologia Embryologica
The Terminologia Embryologica (TE) is a standardized list of words used in the description of human embryologic and fetal structures. It was produced by the Federative International Committee on Anatomical Terminology on behalf of the International Federation of Associations of Anatomists and posted on the Internet since 2010. It has been approved by the General Assembly of the IFAA during the seventeenth International Congress of Anatomy in Cape Town (August 2009).
It is analogous to the Terminologia Anatomica (TA), which standardizes terminology for adult human anatomy and which deals primarily with naked-eye adult anatomy. It succeeds the Nomina Embryologica, which was included as a component of the Nomina Anatomica.It was not included in the original version of the TA.Terminologia Histologica
The Terminologia Histologica (TH) is a controlled vocabulary for use in cytology and histology. In April 2011, Terminologia Histologica was published online by the Federative International Programme on Anatomical Terminologies (FIPAT), the successor of FCAT.
It was intended to replace Nomina Histologica. The Nomina Histologica was introduced in 1977, with the fourth edition of Nomina Anatomica.It was developed by the Federative International Committee on Anatomical Terminology.Uberon
Uberon is a comparative anatomy ontology representing a variety of structures found in animals, such as lungs, muscles, bones, feathers and fins. These structures are connected to other structures via relationships such as part-of and develops-from. One of the uses of this ontology is to integrate data from different biological databases, and other species-specific ontologies such as the Foundational Model of Anatomy.Wingspan
The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the other wingtip. For example, the Boeing 777-200 has a wingspan of 60.93 metres (199 ft 11 in), and a wandering albatross (Diomedea exulans) caught in 1965 had a wingspan of 3.63 metres (11 ft 11 in), the official record for a living bird.
The term wingspan, more technically extent, is also used for other winged animals such as pterosaurs, bats, insects, etc., and other fixed-wing aircraft such as ornithopters.
In humans, the term wingspan also refers to the arm span, which is distance between the length from one end of an individual's arms (measured at the fingertips) to the other when raised parallel to the ground at shoulder height at a 90º angle. Former professional basketball player Manute Bol stands at 7 ft 7 in (2.31 m) and owns one of the largest wingspans at 8 ft 6 in (2.59 m).