Alphabetical list

FMC rules and notations
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Caudal ( Cleland, 1879 ) : Away from the mouth along the longitudinal axis (Barclay, 1803) of the body; the opposite of rostral (Schulze, 1893). Used by Cleland (1879, p. 179) who paired it with cephalic (away from the head or toward the tail). Also see rostrocaudal axis. more details

Cell ( Hooke, 1665 ) : The fundamental structure-function unit of all plants and animals; see Schwann (1839). Discovered microscopically and named in thin sections of cork by Hooke (1665, p. 112 ff.); see Standring (2008, Ch. 1). more details

Cell body ( Deiters, 1865 ) : When referring to neurons (Waldeyer, 1891), it is the trophic center exclusive of neuron extensions-axon (Kölliker,1896), dendrites (His, 1889), and amacrine extensions-with a cell nucleus (Brown, 1833) and perikaryon (Foster & Sherrington, 1897). For neurons the term cell body was used by Deiters (1865, "Körper der Zelle" in the original German; see Van der Loos, 1967, p. 42). Also see Standring (2008, p. 41). more details

Cell group : Often used as a synonym for gray matter region; see Cajal (1909, p. 41), Clark (1938, p. 9), Berman (1968, p. xi), Nauta & Haymaker (1969, pp. 141-142), Swanson (2003, p. 64). Synonyms include cellular aggregate (see Berman, 1968, p. xi), cell collection (see Berman, 1968, p. xi). more details

Cell nucleus ( Brown, 1833 ) : A rounded organelle in the cells (Hooke, 1665) of all organisms except bacteria and similar forms that is enclosed in a double membrane and contains the genetic material of the cell; see Oxford English Dictionary (1989). Not to be confused with gray matter nucleus. Clearly described and named by Brown (1833, p. 709). more details

Center : This term has multiple connotations. It is often used to indicate the site of a particular function, or as a rough synonym for node. It was used essentially in the latter sense as far back as Manfridi (1490; see Singer 1917, p. 108) and Bartholin (1662, p. 142). Of course center can also refer to the middle point of an object. more details

Central ( Barclay, 1803 ) : Toward the center of the body. Barclay (1803, pp. 120-121, 164) introduced a formal distinction between central and peripheral (Barclay, 1803), although use of the term as toward the center of the body goes back at least to Aristotle in De Partibus Animalium; see translation of Ogle (1912, 672-34). more details

Central canal ( C ; Henle, 1871 ) : The narrow, sometimes occluded part of the ventricles (Hippocrates) that is caudal (Cleland, 1879) to the fourth ventricle (Galen, c177), in the caudal (Cleland, 1879) end of the medulla (Winslow, 1733) and in the spinal cord (Galen, c162-c166). At least the initial rostral (Schulze, 1893) part of the central canal of macrodissected adult animals not including humans was observed in the second century by Galen-see translations by De Lacy (1980, pp. 447, 453), May (1968, p. 416), and Duckworth (1962, p. 14)-and was named such by Henle (1871, p. 42), if not earlier. more details

Central ganglion ( GC ) : A ganglion (Galen, c173) of an invertebrate central nerve cord; see Bullock & Horridge (1965, p. 52). more details

Central longitudinal communicating branch : The segment of an invertebrate central nerve cord trunk between two central ganglia associated with the corresponding central nerve cord as a whole. more details

Central nerve cord : For the invertebrate central nervous system (Meckel, 1817), a topographic division that is a longitudinal central nerve cord trunk with a series of more or less regularly spaced central ganglia along its course, and a central nerve cord trunk segment between two adjacent central ganglia called a central longitudinal communicating branch. For invertebrates, the central nervous system (Meckel, 1817) generally consists of one or more central nerve cords, with central transverse communicating branches-commonly referred to as commissures-typically interconnecting central ganglia between central nerve cords (e.g., a right and a left) and forming a ladder-like, or orthogon (see Reisinger, 1925, 1972), arrangement with rostral (Schulze, 1893) and caudal (Cleland, 1879) ends. The most rostral of the central ganglia is commonly called the invertebrate brain or cerebral ganglion. In annelids and arthropods the most rostral of the central ganglia generally lies dorsal (Barclay, 1803) to the digestive system and is called the supraesophageal ganglion, whereas the rest of the central nerve cord lies ventral (Schulze, 1893) to the digestive system. See Bullock & Horridge (1965). more details

Central nerve cord trunk : The equivalent of a white matter tract for an invertebrate central nerve cord, with central ganglia distributed along its length. more details

Central nervous system ( CNS ; Meckel, 1817 ) : In animals with bilateral symmetry, a topographic division that is an obvious condensation of the nervous system (Monro, 1783) in the longitudinal plane (Henle, 1855), lying on or near the median plane (Henle, 1855). For invertebrates this longitudinal division consists of one or more nerve cords, whereas for vertebrates it consists of a single, hollow, and dorsal (Barckay, 1803) cerebrospinal axis (Meckel, 1817). In adult Echinoderms, which are radially symmetrical, a presumptive CNS is formed by a circular cord with associated radial cords, but there is no dominant ganglion (Galen, c173) that could be considered an invertebrate brain; see Bullock & Horridge (1965, pp. 9-14), Heinzeller & Welsch (2001, p. 41). When a CNS is present, its obligate companion topographic division is a peripheral nervous system (Meckel, 1817). While a continuous brain (Edwin Smith Surgical Papyrus, c1700 BC) and spinal cord (Galen, c162-c166) were known to Hippocrates in On the Sacred Disease and Fleshes (see translations by Adams, 1972, p. 351; and Potter, 1995, p. 139, respectively), the term central nervous system as currently understood for vertebrates was first used by Meckel (1817; see English translation, 1832, vol. 1, p. 152). more details

Central transverse communicating branch : The equivalent for invertebrates of a white matter tract interconnecting two central ganglia on different central nerve cords, like the rungs of a ladder. more details

Cerebellum ( CB ; Aristotle ) : The dorsal (Barclay, 1803) topographic division of the hindbrain (Baer, 1837), connected to the ventral (Schulze, 1893) division-the pons (Haller, 1747)-by a white matter tract, the middle cerebellar peduncle. The cerebellum was discovered and named by Aristotle (in De Partibus Animalium) based on macrodissection of a variety of animals not including humans; see translation by Thompson (1910, 494b 30). Older synonyms include parencephalon (Aristotle), hindbrain (Galen, c192). more details

Cerebral aqueduct ( AQ ; His 1895 ) : The part of the ventricles (Hippocrates) in the median plane (Henle, 1855) of the midbrain (Baer, 1837), continuous rostrally (Schulze, 1893) with the third ventricle (Galen, c173) and caudally (Cleland, 1879) with the fourth ventricle (Galen, c177). Vesalius (1543; see translation by Singer , 1952, p. 36; also see May, 1968, pp. 420-423) first clearly described it in macrodissected adult humans, Aranzi (1587, p. 549) first called it an aqueduct, and His (1895, p. 83) called it the cerebral aqueduct for macrodissected adult humans. more details

Cerebral cortex ( CTX ; Bauhin, 1605 ) : The dorsal (Barclay, 1803) topographic division of the endbrain (Kuhlenbeck, 1927), with a basically radial, laminated architecture; the ventral (Schulze, 1893) topographic division is the cerebral nuclei (Swanson, 2000). The cerebral cortex was described and illustrated for macrodissected adult humans by Vesalius (1543), see Singer translation (1952, p. 100 and Fig. 7), and the term itself was introduced for macrodissected adult humans by Bauhin (1605, p. 580), see Meyer (1971, p. 121). Common synonym is pallium (Burdach, 1822). more details

Cerebral ganglia ( Reil, 1809 ) : Basically synonymous with macrodissected adult human cerebral nuclei (Swanson, 2000); see Mayo translation (1823, p. 52). more details

Cerebral ganglion : Synonym for invertebrate brain; see Bullock & Horridge (1965, p. 1609). more details

Cerebral hemispheres ( Tiedemann, 1816 ) : Synonym for endbrain (Kuhlenbeck, 1927). It was used in this way by Teidemann (see 1826 translation, p. 15), and more recently by for example Strong & Elwyn (1943, pp. 13-16), Carpenter (1976, p. 21), Williams & Warwick (1980, p. 864), and Nauta & Feirtag (1986, p. 43), but has also been defined in many other ways. more details

Cerebral nuclei ( CNU ; Swanson, 2000 ) : The ventral (Schulze, 1893) topographic division of the endbrain (Kuhlenbeck, 1927), with a basically nonlaminated architecture; the dorsal (Barclay, 1803) division is the cerebral cortex (Bauhin, 1605). The general outlines of the cerebral nuclei were described for macrodissected adult humans by Bartholin (1651; see English translation 1662, p. 141), and a basic distinction during embryogenesis between cerebral cortex and cerebral nuclei was stressed by Baer (1837) and Reichert (1859-1861). The most common synonym today for cerebral nuclei, which was clearly defined by Swanson (2000, p. 117; 2004, pp. 166-170), is basal ganglia (Warwick & Williams, 1973); also see ganglion (Galen, c173). Other synonyms include corpus striatum (Willis, 1664), cerebral ganglia (Reil, 1809), and basal nuclei (Warwick & Williams, 1973). Cerebral nuclei (Swanson, 2000) is preferred to the synonym basal nuclei (Warwick & Williams, 1973) because it pairs naturally with cerebral cortex (Bauhin, 1605). more details

Cerebral peduncle ( cpd ; Tarin, 1753 ) : The large compact white matter tract of macrodissected adult mammals descending laterally (Barclay, 1803) and ventrally (Schulze, 1893) in the interbrain (Baer, 1837) and tegmentum (Swanson, 2000) of the midbrain (Baer, 1837), as a continuation of the internal capsule (Burdach, 1822). It was clearly illustrated for macrodissected adult humans by Casserio (1609, pp. 123-124, Tab. VII, Fig. 2-C) and Tarin (1753, p. 25) gave its current name, which was followed by Burdach (1822, p. 99; in Latin, "crus cerebri"). more details

Cerebral peduncle ( Vicq d'Azyr, 1784 ) : Synonym for macrodissected adult human tegmentum (Swanson, 2000); pp. 555-556. Later used thus by for example His (1893b, p. 178), Herrick (1915, p. 160), Strong & Elwyn (1943, p. 17), Carpenter (1976, p. 367), Williams & Warwick (1980, p. 935). more details

Cerebral ventricles : Synonym for ventricles (Hippocrates). more details

Cerebrospinal axis ( CSA ; Meckel, 1817 ) : In popular usage it is a topographic division that corresponds to the vertebrate central nervous system (Meckel, 1817), although in fact it applies more generally to the chordate central nervous system (Meckel, 1817), a hollow tubular division of the nervous system (Monro, 1783) that lies in the median plane (Henle, 1855), dorsal (Barclay, 1803) to a notochord and flanked by a bilateral (Aristotle) series of segmental muscles (Nieuwenhuys, 2002). Since Classical Antiquity at least six fundamentally different ways to divide the cerebrospinal axis have been used, although today there is rather broad consensus about a set of major topographic divisions of cerebrospinal axis. The set of divisions is arranged in a hierarchical parceling scheme that is based primarily on structural differentiation of the neural tube (Baer, 1837) and its end product is adult macrostructure or gross anatomy (Swanson, 2000). The term cerebrospinal axis was introduced by Meckel (1817; see English translation, 1832, vol. 2, p. 410) for macrodissected adult humans although the feature itself was known to Herophilus (335-280 BC; see von Staden, 1989, p. 159). more details

Cerebrum ( Obersteiner & Hill, 1900 ) : Synonym for endbrain (Kuhlenbeck, 1927). It was used in this way by for example Obersteiner & Hill (1900, pp. xv, 47), Crosby et al. (1962, p. 356), Williams & Warwick (1980, p. 864), Nauta & Feirtag (1986, p. 43), and Nieuwenhuys et al. 2008, p. 5, Fig. 1.2), but has also been defined in many other ways. Curiously, in English, the Greek (encephalon) and Latin (cerebrum) forms of "brain" are not synonymous (see Oxford English Dictionary, 1989). This goes back to Aristotle, who distinguished a large brain (cerebrum) and small brain (cerebellum, the diminutive of cerebrum); see Swanson (2000) and His (1895, p. 162). more details

Cerebrum ( Varolio, 1573 ) : Synonymous with forebrain (Goette, 1873); see Clarke & O'Malley (1996, pp. 635, 881-882). more details

Cerebrum ( Vesalius, 1543 ) : Synonymous with forebrain (Goette, 1873) together with midbrain (Baer, 1837); see Singer translation (1952, pp. 36, 46-47). Also see His (1895, p. 162). more details

Chain : The sequence or series of connections between an arbitrary set of nodes. There are open chains and closed chains; synonyms for the latter are circuit, loop, and cycle. Chain is a traditional term to describe neural network organization and has been widely used in this sense at least since Foster & Sherrington (1897, p. 979), Barker (1899, pp. 313-320), Schäfer (1900, vol. 2, p. 608). more details

Chemical synapse : A synapse (Foster & Sherrington, 1897) using only neurotransmitters for communicating between the presynaptic compartment (De Camilli et al., 2001) and postsynaptic compartment (De Camilli et al., 2001); see Cowan et al. (2001). more details

Circuit : Synonym for closed chain. Generally, a circuit is a closed path that begins and ends in the same place (Oxford English Dictionary, 1989). In graph theory it is also called a cycle. more details

Circuitry : A vague term referring to all or part of the connectome or complete wiring diagram; it should be avoided, see circuit. more details

Circular cord : Synonym for circumoral nerve ring; see Bullock & Horridge (1965, p. 12). more details

Circumenteric nerve ring : Regarded as the central nervous system (Meckel, 1817) of Nematodes and Priapulids; see Bullock & Horridge (1965, pp. 605, 658). more details

Circumoral nerve ring : The nerve ring in adult Echinoderms, where there is no convincing evidence that the nervous system (Monro, 1783), which is a nerve net, is divided into central nervous system (Meckel, 1817) and peripheral nervous system (Meckel, 1817); see Bullock & Horridge (1965, p. 1525), Cobb (1995, p. 411). There is also a circumoral nerve ring with a ganglion (Galen, c173) in Phoronida; see Bullock & Horridge (1965, p. 641). more details

Closed chain ( Swanson & Bota, 2010 ) : A series of connections in a topological circle; that is, one can start at any node and follow connections back to the same node; synonyms include circuit, loop, and cycle. more details

Collateral ( Waldeyer, 1891 ) : Short form of axon collateral (Cajal, 1899); name provided by Waldeyer (1891; see Shepherd, 1991, p. 36). more details

Commissure : When a white matter tract crosses the median plane (Henle, 1855) in animals with bilateral symmetry and then assumes a transverse course, the crossing segment is called a commissure. Generally, a commissure forms connections between the same or nearby gray matter regions on the right and left sides. The term was used in this sense as long ago as Willis (1664, see translation by Pordage, 1681, p. 159). Also see Nauta & Feirtag (1986, p. 82, note). more details

Communicating branch ( cbr ; Winslow, 1733 ) : A general term for a short white matter tract between two nerve cords, two nerves (Herophilus, c335-280 BC), two ganglia (Galen, c173), or a ganglion and a nerve. Galen (c180; see translation by Goss, 1966, p. 330) referred to communications between nerves and Winslow (1733, Sect. VI) frequently used the term communicating branch in describing macrodissected adult human nerves. more details

Connection ( Bota et al. 2003 ) : The overall structural link between two nodes in the wiring diagram of the nervous system (Monro, 1783); synonyms include structural connection and projection. The nodes may be described at three successively greater levels of resolution and accuracy. For a macroconnection (Thompson & Swanson, 2010) the two nodes are gray matter regions, for a mesoconnection (Thompson & Swanson, 2010) the nodes are neuron types (Bota & Swanson, 2007), and for a microconnection (Thompson & Swanson, 2010) the nodes are individual neurons (Waldeyer, 1891). A node can establish one or more connections that are either an intranodal connection(s) or an internodal connection(s). An axon connection is unidirectional, whereas an amacrine connection (amacrine extension connection) is bidirectional. The physical course taken by a connection through gray matter regions and white matter tracts is called its route, and route information is part of the description of a connection. Information about a set of connections can be arranged in a number of different ways like a wiring diagram, connectome, or basic plan. A closely related concept is pathway-the part of a connection demonstrated in a particular experimental analysis; another related term is functional connection. "Connections" between parts of the vertebrate brain (Cuvier, 1800) were described at least as early as Gordon (1817, p. 134); for its use as defined here see Bota et al. (2003, p. 795). Also see connections. more details

Connections ( Swanson & Bota, 2010 ) : The total input-output relationships of a node or set of nodes, in contrast to an individual connection. more details

Connectome ( Bota and Swanson, 2010 ) : For the Foundational Model of Connectivity, the complete structural connection matrix of nodes forming the nervous system (Monro, 1783) of a particular animal species, or in a more limited sense the complete input/output connection matrix of a particular node; also see connectome (Sporns et al., 2005). more details

Connectome ( Sporns et al., 2005 ) : A "connection matrix of the human brain … a comprehensive structural description of the network of elements and connections forming the human brain"; p. 245. more details

Contralateral : On the opposite side of the body in an animal with bilateral symmetry; see Standring (2008, p. xxii). more details

Coronal plane ( Barclay, 1803 ) : Synonym for frontal plane (Henle, 1855), named for the human coronal suture, named in turn for the crown of the human head; p. 145. It is commonly used thus in human and other primate anatomy; see Standring (2008, Fig. 1). It is often confusingly used in quadrupeds for transverse plane (Henle, 1855); see coronal plane (Paxinos & Watson, 1982). more details

Coronal plane ( Paxinos & Watson, 1982 ) : Synonym for transverse plane (Henle, 1855); p. 2. Used occasionally in comparative anatomy, probably before Paxinos & Watson (1982). Also see coronal plane (Barclay, 1803). more details

Corpora quadrigemina ( Winslow, 1733 ) : Synonym for macrodissected adult human tectum (Schwalbe, 1881); Sect. X, p. 37. Quadrigeminal body in English. more details

Corpus striatum ( Willis, 1664 ) : Basically synonymous with cerebral nuclei (Swanson, 2000) as Willis defined the term for macrodissected large mammals including humans; pp. 62-63, 101-102, Tab. VIII-A. Striate body in English. more details

Cranial nerve ganglia ( GCR ) : The topographic division consisting of sensory ganglia (Galen, c173) associated with the cranial nerves (Longet, 1842), in contrast to the autonomic ganglia (Langley, 1900) associated with the cranial nerves (Longet, 1842); see International Anatomical Nomenclature Committee (1983; p. A73), Federative Committee on Anatomical Terminology (1998, p. 132). more details

Cranial nerves ( cran ; Longet, 1842 ) : The topographic division of vertebrate craniospinal nerves (Herrick, 1915) that exit the cranium despite their origin; for example the spinal root of accessory nerve, which is motor in function, arises from the ventral horn of the spinal cord (Galen, c162-c166) but exits the cranium with the vagus nerve (Galen, c192 AD), another cranial nerve. Most of them were known to Herophilus (335-280 BC), the founder of human anatomy (see Solmsen, 1961; von Staden, 1989), and the term itself was first used for macrodissected animals except humans by Galen in the second century, although not in the currently accepted sense; see translations by Duckworth (1962, pp. 181-222) and May (1968, pp. 31-32, 438-454). The traditional division into 12 cranial nerves is based on the work of Soemmerring (1778, pp. 173-180), who later called them cerebral nerves (Soemmerring, 1791, sections 128, 203-272); they were finally called the 12 cranial nerves by Longet (1842, vol. 2, p. 1). more details

Craniospinal ganglia ( GCS ) : A topographic division of vertebrate peripheral ganglia that includes cranial nerve ganglia and spinal nerve ganglia (Burdach, 1819) considered together, all of which are sensory in function and contrasted with the autonomic ganglia (Langley, 1900). The history of their discovery is complex, beginning with the discovery of spinal nerve ganglia by Coiter (1572, see 1995 translation p. 115). Also see International Anatomical Nomenclature Committee (1983; p. A73), Federative Committee on Anatomical Terminology (1998, p. 132). more details

Craniospinal nerves ( CSN ; Herrick, 1915 ) : A topographic division of vertebrate nerves (Herophilus, c335-280 BC) consisting of the 12 traditional pairs of cranial nerves (Longet, 1842) and the variable number in different species of pairs of spinal nerves (Camper, 1760) considered together, and distinguished from the autonomic nerves (Langley, 1898). Most craniospinal nerves were known to Herophilus (335-280 BC), the founder of human anatomy (see Solmsen, 1961; von Staden, 1989), and the term itself was used by Herrick (1915, p. 223), and later by others including Williams & Warwick (1980, p. 1052). more details

Cycle : In graph theory a synonym for closed chain or circuit. more details