Uberon is an integrated cross-species anatomy ontology representing a variety of entities classified according to traditional anatomical criteria such as structure, function and developmental lineage. The ontology includes comprehensive relationships to taxon-specific anatomical ontologies, allowing integration of functional, phenotype and expression data.
The subdivision of the vertebrate body between the thorax and pelvis. The ventral part of the abdomen contains the abdominal cavity and visceral organs. The dorsal part includes the abdominal section of the vertebral column.
Abdominal part of aorta: the distal part of the descending aorta, which is the continuation of the thoracic part and gives rise to the inferior phrenic, lumbar, median sacral, superior and inferior mesenteric, middle suprarenal, renal, and testicular or ovarian arteries, and celiac trunk[BTO]. The abdominal aorta is the largest artery in the abdominal cavity. As part of the aorta, it is a direct continuation of descending aorta(of the thorax). [WP,unvetted].
A membranous sac that develops from the posterior part of the alimentary canal in the embryos of mammals, birds, and reptiles, and it is important in the formation of the umbilical cord and placenta in mammals[VHOG].
Anatomical space which contains portions of one or more body substances and is bounded by the internal surface of one maximally connected anatomical structure. Examples: cranial cavity, pharyngeal recess space, nasal cavity, tooth socket, cavity of serous sac, lumen of stomach, lumen of artery, fornix of vagina.
Non-material anatomical entity of three dimensions, that is generated by morphogenetic or other physiologic processes; is surrounded by one or more anatomical structures; contains one or more organism substances or anatomical structures.
A two dimensional anatomical structure that is the boundary between an anatomical structure and an anatomical substance, an anatomical space or the organism’s environment. Examples include the surface of your skin, the surface of the lining of your gut; the surface of the endothelium of you aorta that is in contact with blood.n Old definition: ‘Non-material anatomical entity of two dimensions, that is demarcated by anatomical lines or points on the external or internal surfaces of anatomical structures.’ Note, in the new definition, the space referred to is not necessarily an anatomical space. It may be the outside of an organism.
The space in the eye, filled with aqueous humor, and bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and part of the crystalline lens.
A transparent homogeneous acellular layer, 6 to 9 um thick, lying between the basal lamina of the outer layer of stratified epithelium and the substantia propria of the cornea; it is considered to be a basement membrane.
Orifice at the opposite end of an animal’s digestive tract from the mouth. Its function is to expel feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest, such as bones; food material after all the nutrients have been extracted, for example cellulose or lignin; ingested matter which would be toxic if it remained in the digestive tract; and dead or excess gut bacteria and other endosymbionts.
The main trunk of the systemic arterial system that carries blood from the heart to all the organs and other structures of the body, bringing oxygenated blood to all parts of the body in the systemic circulation.
The dilated structure that is lined by endothelial cells and located at the arterial pole of the heart just above (distal to) the truncus arteriosus in mammalian embryos; it is the primordial vascular channel from which the aortic arches (and eventually the dorsal aortae) arise; the aortic sac is homologous to the ventral aorta of gill-bearing vertebrates.
The spiral septum that separates the truncus arteriosus into a ventral pulmonary trunk and the dorsal aorta[MP]. The aorticopulmonary septum is developmentally formed from neural crest, specifically the cardiac neural crest, and actively separates the aorta and pulmonary arteries and fuses with the interventricular septum within the heart during development. The actual mechanism of septation of the outflow tract is poorly understood, but is recognized as a dynamic process with contributions from contractile, hemodynamic, and extracellular matrix interactions.
Multilayered ectodermal region at the distal tip of a limb or fin bud necessary for the proper development of the underlying mesenchyme[MP,modified]. Along with the zone of polarizing activity, it is a crucial organizing region during limb development[WP].
The convex portion of the aorta between the ascending and descending parts of the aorta; branches from it include the brachiocephalic trunk, the left common carotid artery, and the left subclavian artery; the brachiocephalic trunk further splits to form the right subclavian artery and the right common carotid artery.
The inferior labial artery (inferior labial branch of facial artery) arises near the angle of the mouth; it passes upward and forward beneath the Triangularis and, penetrating the Orbicularis oris, runs in a tortuous course along the edge of the lower lip between this muscle and the mucous membrane. It supplies the labial glands, the mucous membrane, and the muscles of the lower lip; and anastomoses with the artery of the opposite side, and with the mental branch of the inferior alveolar artery.
Sense organ embedded in the integument and consisting of one or a cluster of sensory neurons and associated sensory structures, support cells and glial cells forming a single organised unit with a largely bona-fide boundary.[FBbt].
One of the main divisions of the whole organism of arthropods formed from groups of segments. Strictly speaking the term “tagma” cam be used for any metameric organism, however we follow the common usage which is to restrict the term to arthropods.
The ascending aorta is the portion of the aorta in a two-pass circulatory system that lies between the heart and the arch of aorta[GO]. A portion of the aorta commencing at the upper part of the base of the left ventricle, on a level with the lower border of the third costal cartilage behind the left half of the sternum; it passes obliquely upward, forward, and to the right, in the direction of the heart’s axis, as high as the upper border of the second right costal cartilage, describing a slight curve in its course, and being situated, about 6 cm behind the posterior surface of the sternum. The total length is about 5 cm in length [Wikipedia].
Ganglion that has dendrites that form a junction between autonomic nerves originating from the central nervous system and autonomic nerves innervating their target organs in the periphery. There are two subtypes, sympathetic ganglion and parasympathetic ganglion.
The autonomic nerve is a small nerve which carries postganglionic sympathetic and parasympathetic neurons from the zygomaticotemporal nerve; a branch of the maxillary nerve, to the lacrimal nerve; a branch of the ophthalmic nerve. These neurons derive from the superior cervical ganglion and the pterygopalatine ganglion respectively. They will travel to the lacrimal gland via the lacrimal nerve. Parasympathetic will induce lacrimation and vice versa.
The autonomic nervous system is composed of neurons that are not under conscious control, and is comprised of two antagonistic components, the sympathetic and parasympathetic nervous systems. The autonomic nervous system regulates key functions including the activity of the cardiac (heart) muscle, smooth muscles (e.g. of the gut), and glands[GO].
A flattened, almost circular bilaminar plate of cells formed when the inner cell mass (aka embryoblast) forms two epithelial layers, each of a distinct lineage, separated by an extracellular basement membrane: the external (dorsal) layer is called the epiblast and the internal (ventral) layer is called the hypoblast (aka primitive endoderm); together, they compose the bilaminar embryonic disc.
One of the fine terminal elements of the bile duct system, leaving the portal canal, and pursuing a course at the periphery of a lobule of the liver[BTO]. the excretory ducts of the liver that connect the interlobular ductules to the right or left hepatic duct[MP].
Organ system subdivision that consists of the organs and ducts that are involved in the production and transportation of bile. In most species this is the gallbladder and the bile ducts (biliary tree).
A complex network of conduits that begins with the canals of Hering (intralobar bile duct) and progressively merges into a system of interlobular, septal, and major ducts which then coalesce to form the extrahepatic bile ducts, which finally deliver bile to the intestine, and in some species to the gallbladder. The path in many species is as follows: Bile canaliculi -> Canals of Hering (intralobar bile duct) -> interlobular bile ducts -> intrahepatic bile ducts -> left and right hepatic ducts merge to form -> common hepatic duct exits liver and joins -> cystic duct (from gall bladder) forming -> common bile duct -> joins with pancreatic duct -> forming ampulla of Vater -> enters duodenum [WP]
Organism at the blastula stage - an early stage of embryonic development in animals. It is produced by cleavage of a fertilized ovum and consists of a spherical layer of around 128 cells surrounding a central fluid-filled cavity called the blastocoel. The blastula follows the morula and precedes the gastrula in the developmental sequence.
An early stage of embryonic development in animals. It is produced by cleavage of a fertilized ovum and consists of a spherical layer of around 128 cells surrounding a central fluid-filled cavity called the blastocoel. The blastula follows the morula and precedes the gastrula in the developmental sequence.
Blood islands are structures in the developing embryo which lead to many different parts of the circulatory system. They primarily derive from plexuses formed from angioblasts. Within them, vacuoles appear through liquefaction of the central part of the syncytium into plasma. The lumen of the blood vessels thus formed is probably intracellular. The flattened cells at the periphery form the endothelium. The nucleated red blood corpuscles develop either from small masses of the original angioblast left attached to the inner wall of the lumen or directly from the flat endothelial cells. In either case the syncytial mass thus formed projects from and is attached to the wall of the vessel. Such a mass is known as a blood island and hemoglobin gradually accumulates within it. Later the cells on the surface round up, giving the mass a mulberry-like appearance. Then the red blood cells break loose and are carried away in the plasma. Such free blood cells continue to divide. Blood islands have been seen in the area vasculosa in the omphalomesenteric vein and arteries, and in the dorsal aorta[WP, unvetted].
Any of the smallest blood vessels where blood circulates within organ tissues. Microvessels include terminal arterioles, metarterioles, capillaries, and venules (but exclude lymphatic capillaries). Arterioles carry oxygenated blood to the capillaries, and blood flows out of the capillaries through venules into veins.
An anatomical boundary that corresponds to some physical discontinuity. One might argue that all boundaries are actually fiat in the sense that there must be some fiat element at a fine enough scale of granularity. This ontology choses to ignore this issue as below the level of granularity relevant to anatomy. (DOS121102)
Skeletal tissue with a collagen-rich extracellular matrix vascularized, mineralized with hydroxyapatite and typically including osteocytes located in lacunae that communicate with one another by cell processes (in canaliculi). Bone is deposited by osteoblasts.
The left and right brachiocephalic veins in the upper chest are formed by the union of each corresponding internal jugular vein and subclavian vein. This is at the level of the sternoclavicular joint. These great vessels merge to form the superior vena cava. The brachiocephalic veins are the major veins returning blood to the superior vena cava.
The brain is the center of the nervous system in all vertebrate, and most invertebrate, animals. Some primitive animals such as jellyfish and starfish have a decentralized nervous system without a brain, while sponges lack any nervous system at all. In vertebrates, the brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing, balance, taste, and smell[WP].
Stalk-like part of the brain that includes amongst its parts the medulla oblongata of the hindbrain and the tegmentum of the midbrain[ZFA,MP,generalized]. ‘brainstem’ is a loose term that sometimes refers to the ventral parts o the brain except for any part of the telencephalon - sometimes it includes the diencephalon or subpallial telencephalon structures (ISBN:0471888893). Here we use it in a more restriced sense, to include only the medulla oblongata, pons (when present) and the midbrain tegmentum (following the ZFA definitions).
The bronchial veins are small vessels that return blood from the larger bronchi and structures at the roots of the lungs. The right side drains into the azygos vein, while the left side drains into the left superior intercostal vein or the accessory hemiazygos vein. The bronchial veins are counterparts to the bronchial arteries. The veins, however, do not return all of the blood supplied by the arteries; much of the blood that is carried in the bronchial arteries is returned to the heart via the pulmonary veins. [WP,unvetted].
The conducting airway of the lungs found terminal to the bronchi; these structures contain neither cartilage nor mucous-secreting glands; the epithelium of the bronchioles becomes thinner with each branching.
The thin bilaminar membrane derived from the prechordal plate that is devoid of mesoderm and formed by the apposition of the stomodeal ectoderm with the foregut endoderm; after the embryonic head fold has evolved it lies at the caudal limit of the stomodeum, forming a septum between the primitive mouth and pharynx; the membrane eventually disappears, and thus a communication is established between the mouth and the future pharynx.
A cardiac chamber surrounds an enclosed cavity within the heart. generic enough to cover FBbt:00003156 heart chamber but this is a cavity. GO defines it as the cavity. TODO - move subclasses. Note this also includes sinus venosus
Portion of neural crest that develops from the dorsal neural tube. It overlaps the vagal neural crest and migrates to populate the pharyngeal arches 3, 4 and 6 (producing structures in the head) and to the heart, forming connective tissue that separates the great vessels of the heart. [Wikipedia].
The splanchnic mesoderm in the cardiogenic region where the heart develops; it gives rise to endocardial heart tubes that fuse to form the primordial cardiac tube, the heart primordium[web]. Two migratory heart primordia that move ventrally during the course of neurulation, and then fuse[XAO].
An region of the mesoderm that includes anterior lateral mesoderm of the first heart field plus contiguous pharyngeal mesoderm that gives rise to second-heart-field-derived regions of the heart and branchiomeric muscles.
The hyaline cartilaginous structures that support the bronchi, present as irregular rings in the larger bronchi (and not as regular as in the trachea), and as small plates and islands in the smaller bronchi; as the branching continues through the bronchial tree, the amount of hyaline cartilage in the walls decreases until it is absent in the smallest bronchioles[MP].
Skeletal tissue that is avascular, rich in glycosaminoglycans (GAGs) and typically includes chondrocytes within isolated lacunae. Cartilage tissue is deposited by chondroblasts. Previous: “A portion of connective tissue dominated by extracellular matrix containing collagen type II and large amounts of proteoglycan, particularly chondroitin sulfate[GO]. Regular connective tissue, which consists of chondrocytes and related cells, the intercellular matrix of which is chondrified. Examples: hyaline cartilage, fibrocartilage, elastic cartilage[FMA]. an avascular supporting and articular skeletal tissue. It also functions as the primary endoskeletal support in vertebrate embryos. Cartilage is deposited by and is composed of chondroblasts and chondrocytes separated by an extracellular matrix, which may or may not mineralize depending on cartilage type, age, or taxon[Hall and Witten].” See also FMA:71500 Set of cartilages, FMA:55107 Cartilage organ, FMA:12264 Articular cartilage. // elements made from cartilage, cartilage-like, or chondroid tissues evolved in invertebrates[H&W]
The primitive cartilagionous skeletal structure of the fetal skull that grows to envelop the rapidly growing embyonic brain. In humans, the chondrocranium begins forming at 28 days from mesenchymal condensations and is fully formed between week 7 and 9 of fetal development. While the majority of the chondrocranium is succeeded by the bony skull in most higher vertebrates, some components do persist into adulthood. In Cartilagious fishes and Agnathans, the chondrocranium persist throughout life. Embryologically, the chondrocranium represent the basal cranial structure, and lay the base for the formation of the endocranium in higher vertebrates[WP].
A small cluster of cells of various types which form a discrete structure, largely delimited by a morphological boundary and whose components work together to make the whole structure capable of a specific function. Examples include arthropod sensilla.
Anatomical structure that is an aggregation of similar cells from which cartilages and bones form, and from which chondrogenesis and osteogenesis are initiated during repair and/or regeneration. (Hall and Miyake 1995).
The central nervous system is the core nervous system that serves an integrating and coordinating function. In vertebrates it consists of the neural tube derivatives: the brain and spinal cord. In invertebrates it includes central ganglia plus nerve cord.
A portion of the respiratory and digestive tracts; its distal limit is the superior part of the esophagus and it connects the nasal and oral cavities with the esophagus and larynx; it contains the valleculae and the pyriform recesses; its upper limits are the nasal cavity and cranial base.[FEED]. Consider generalizing to deuterostome pharynx
That portion of the chorionic wall in the region of its uterine attachment, which gives rise to chorionic villi; it consists of the mesoderm that lines the chorionic vesicle and, on the maternal side, of the trophoblast that lines the intervillous spaces; in the last half of gestation, the mesodermal connective tissue is largely replaced by fibrinoid material, and the amnionic membrane is adherent to the fetal side of the plate.
The ciliary muscle is a ring of smooth muscle in the middle layer of the eye that controls the eye’s accommodation for viewing objects at varying distances and regulates the flow of aqueous humour through Schlemm’s canal. [WP,unvetted].
The ciliary processes are formed by the inward folding of the various layers of the choroid, i.e. , the choroid proper and the lamina basalis, and are received between corresponding foldings of the suspensory ligament of the lens.
A hollow, muscular organ, which, by contracting rhythmically, contributes to the circulation of lymph, blood or analogs. Examples: a chambered vertebrate heart; the tubular peristaltic heart of ascidians; the dorsal vessel of an insect; the lymoh heart of a reptile.
Organ system that passes nutrients (such as amino acids and electrolytes), gases, hormones, blood cells, etc. to and from cells in the body to help fight diseases and help stabilize body temperature and pH to maintain homeostasis[WP].
The first few specialized divisions of an activated animal egg; Stage consisting of division of cells in the early embryo. The zygotes of many species undergo rapid cell cycles with no significant growth, producing a cluster of cells the same size as the original zygote. The different cells derived from cleavage are called blastomeres and form a compact mass called the morula. Cleavage ends with the formation of the blastula.
The cavity within the body of all animals higher than the coelenterates and certain primitive worms, formed by the splitting of the embryonic mesoderm into two layers. In mammals it forms the peritoneal, pleural, and pericardial cavities.
An epithelium that consists of columnar epithelial cells. Columnar epithelia are epithelial cells whose heights are at least four times their width. Columnar epithelia are divided into simple (or unilayered), and the rarer stratified (or multi-layered).[WP, modified].
In anatomy, the common hepatic artery is a short blood vessel that supplies oxygenated blood to the liver, pylorus (a part of the stomach), duodenum (a part of the small intestine) and pancreas. It arises from the celiac artery and has the following branches:.
Predominantly extrahepatic bile duct which is formed by the junction of the right and left hepatic ducts, which are predominantly intrahepatic, and, in turn, joins the cystic duct to form the common bile duct[GAID]. The common hepatic duct is the duct formed by the convergence of the right hepatic duct (which drains bile from the right functional lobe of the liver) and the left hepatic duct (which drains bile from the left functional lobe of the liver). The common hepatic duct then joins the cystic duct coming from the gallbladder to form the common bile duct[WP].
Anatomical structure that has as its parts two or more multi-tissue structures of at least two different types and which through specific morphogenetic processes forms a single distinct structural unit demarcated by bona fide boundaries from other distinct anatomical structures of different types.
The embryo and its adnexa (appendages or adjunct parts) or associated membranes (i.e. the products of conception) The conceptus includes all structures that develop from the zygote, both embryonic and extraembryonic. It includes the embryo as well as the embryonic part of the placenta and its associated membranes - amnion, chorion (gestational sac), and yolk sac[WP].
A conical pouch formed from the upper and left angle of the right ventricle in the chordate heart, from which the pulmonary artery arises[WP]. the anteriosuperior, smooth-walled portion of the cavity of the right ventricle, beginning at the supraventricular crest and terminates in the pulmonary trunk[MP].
The edge of the cornea where it joins the sclera; the limbus is a common site for the occurrence of corneal epithelial neoplasm. This location has parts such as blood vessels etc. See PMC2868485, http://www.ncbi.nlm.nih.gov/pubmed/2695343
The costocervical trunk arises from the upper and back part of the subclavian artery, behind the scalenus anterior on the right side, and medial to that muscle on the left side. Passing backward, it splits into the deep cervical artery and the supreme intercostal artery (or the Highest intercostal artery), which descends behind the pleura in front of the necks of the first and second ribs, and anastomoses with the first aortic intercostal (3rd posterior intercostal artery). As it crosses the neck of the first rib it lies medial to the anterior division of the first thoracic nerve, and lateral to the first thoracic ganglion of the sympathetic trunk. In the first intercostal space, it gives off a branch which is distributed in a manner similar to the distribution of the aortic intercostals. The branch for the second intercostal space usually joins with one from the highest aortic intercostal artery. This branch is not constant, but is more commonly found on the right side; when absent, its place is supplied by an intercostal branch from the aorta. Each intercostal gives off a posterior branch which goes to the posterior vertebral muscles, and sends a small spinal branch through the corresponding intervertebral foramen to the medulla spinalis and its membranes. [WP,unvetted].
Any skeletal muscle that is part of the head region. defined generically so could in theory encompass FBbt:00003260 ‘skeletal muscle of head’, or the muscle of a starfish Aristotle’s lantern, but we restrict this to craniates. Skeletal muscles of the head originate from the non-segmented head mesoderm (Noden, 1983; Wachtler et al., 1984)
Neural crest cells (NCCs) originating in the anterior part of the developing embryo and residing between the mid-diencephalon and the forming hindbrain; cranial NCCs migrate dorsolaterally to form the craniofacial mesenchyme that differentiates into various craniofacial cartilages and bones, cranial neurons, glia, and connective tissues of the face; these cells enter the pharyngeal pouches and arches where they give rise to thymic cells, bones of the middle ear and jaw (mandible), and the odontoblasts of the tooth primordia; like their counterparts in the trunk, cranial NCCs also contribute to the developing peripheral nervous system, along with the pigmented cell (i.e. melanocyte) lineage.
Any of the cranial nerves, or their central nervous system analogs (the optic tract, the epiphyseal tract). These analogs are not true nerves, and are instead evaginated sensory afferents emanating from the brain.
Dense connective tissue is mainly composed of collagen type I. Crowded between the collagen fibers are rows of fibroblasts, fiber-forming cells, that manufacture the fibers. Dense connective tissue forms strong, rope-like structures such as tendons and ligaments. Tendons attach skeletal muscles to bones; ligaments connect bones to bones at joints. Ligaments are more stretchy and contain more elastic fibers than tendons. Dense connective tissue also make up the lower layers of the skin (dermis), where it is arranged in sheets.
Irregular connective tissue is an irregular connective tissue, the intercellular matrix of which contains a dense irregular network of collagen and elastic fiber bundles. Examples: connective tissue of peritoneum, connective tissue of fibrous pericardium.
Skeletal subdivision that undergoes direct development and includes elements that either develop in association with the basement membrane of the ectoderm or are homologous with such elements; includes dermatocranium, components of the appendicular skeleton, teeth and tooth-like elements of the oropharynx, and integumentary elements. This ontology covers metazoa, so we do not use exoskeleton as primary label, as in VSAO
A transparent homogeneous acellular layer found between the substantia propria and the endothelial layer of the cornea[MP]. The strong, resistant, thin, noncellular fourth layer of the cornea, located between the endothelium (from which it is secreted) and the stroma. (Cline et al., Dictionary of Visual Science, 4th ed)
The descending aorta is the portion of the aorta in a two-pass circulatory system from the arch of aorta to the point where it divides into the common iliac arteries[GO]. The descending aorta is part of the aorta, the largest artery in the body. The descending aorta is the part of the aorta beginning at the aortic arch that runs down through the chest and abdomen. The descending aorta is divided into two portions, the thoracic and abdominal, in correspondence with the two great cavities of the trunk in which it is situated. Within the abdomen, the descending aorta branches into the two common iliac arteries which serve the legs. [WP,unvetted].
The dorsal aorta is a blood vessel in a single-pass circulatory system that carries oxygenated blood from the gills to the rest of the body. In a single-pass circulatory system blood passes once through the heart to supply the body once.
The portion of mesentery attached to the greater curvature of the stomach is named the dorsal mesentery (or dorsal mesogastrium, when referring to the portion at the stomach), and the part which suspends the colon is termed the mesocolon. The dorsal mesogastrium develops into the greater omentum.
Subdivision of thorax, which in humans is the posterior part of the thorax and is demarcated from the chest by the external surface of the posterolateral part of the rib cage and the anterior surface of the thoracic vertebral column; together with the chest, it constitutes the thorax.
A major subdivision of an organism that is the entire part of the organism dorsal to a horizontal plane and bounded on one side by the same transverse plane. In vertebrares this includes the vertebral column..
A compound tubular submucosal gland found in that portion of the duodenum which is above the hepatopancreatic sphincter (Sphincter of Oddi). The main function of these glands is to produce a mucus-rich alkaline secretion (containing bicarbonate)[WP].
One of the two small elevations on the mucosa of the duodenum, the major at the entrance of the conjoined pancreatic and common bile ducts and the minor at the entrance of the accessory pancreatic duct.
The first part of the small intestine. At the junction of the stomach and the duodenum the alimentary canal is inflected. The duodenum first goes anteriorly for a short distance, turns dorsally, and eventually caudally, thus it is a U-shaped structure with two horizontal sections (a ventral and a dorsal one).
Anatomical entity that comprises the organism in the early stages of growth and differentiation that are characterized by cleavage, the laying down of fundamental tissues, and the formation of primitive organs and organ systems. For example, for mammals, the process would begin with zygote formation and end with birth. For insects, the process would begin at zygote formation and end with larval hatching. For plant zygotic embryos, this would be from zygote formation to the end of seed dormancy. For plant vegetative embryos, this would be from the initial determination of the cell or group of cells to form an embryo until the point when the embryo becomes independent of the parent plant.
Endoderm-lined chamber that develops as pouch-like dilation of the caudal end of the hindgut and receives the allantois ventrally and two mesonephric ducts laterally; caudally it ends blindly at the cloacal membrane formed by the union of proctodeal (anal pit) ectoderm and cloacal endoderm, with no intervening mesoderm[MP].
The endocardial cushion is a specialized region of mesenchymal cells that will give rise to the heart septa and valves[GO]. Swellings of tissue present between the endocardial and myocardial cell layers that will give rise to the interstitial cells of the cardiac valves[ZFA]. GO graph seems to suggest this is an endothelium. WP: The endocardial cushions are thought to arise from a subset of endothelial cells that undergo epithelial to mesenchymal transformation, a process whereby these cells break cell-to-cell contacts and migrate into the cardiac jelly (towards to interior of the heart tube). Latest (2010-06-01) new def suggested for GO, added above. Note that EHDAA2 has a more detailed model which we may later adopt. JB: Patterning makes the cushions lay down connective tissue in three domains that force out the local endothelial lining and so the leaflets form
The endocardium is an anatomical structure comprised of an endothelium and an extracellular matrix that forms the innermost layer of tissue of the heart, and lines the heart chambers[GO]. fixed in GO to reflect FMA. See email to David/Varsha June 18 2010
A layer of epithelium that lines the heart, blood vessels (endothelium, vascular), lymph vessels (endothelium, lymphatic), and the serous cavities of the body[MESH]. Simple squamous epithelium which lines blood and lymphatic vessels and the heart[FMA]. The term ’endothelium’ has been either restricted to the continuous cell layer of the vertebrates, as we are assuming here, or applied to all the cells able to adhere to the luminal surface of the vascular basement membrane (Casley-Smith 1980)
The sum total of mesenchymal tissue in the pharyngeal arch region. Pharyngeal mesenchyme is undifferentiated, loose connective tissue derived mostly from mesoderm, and also contains ectodermally derived neural crest cells.
In amniote animal embryology, the epiblast is a tissue type derived either from the inner cell mass in mammals or the blastodisc in birds and reptiles. It lies above the hypoblast. In mammalian embryogenesis, the columnar cells of the epiblast are adjacent to the trophoblast, while the cuboidal cells of the hypoblast are closer to the blastocoele. The epiblast, whilst referred to as the primary ectoderm, differentiates to form all three layers of the trilaminar germ disc in a process called gastrulation[WP]. The outer of the two layers of the blastoderm that form during gastrulation, corresponding to primitive ectoderm during gastrulation and to the definitive ectoderm after gastrulation[ZFA]
Focal thickenings of the embryonic ectoderm that form immediately dorsal and caudal of the clefts between the pharyngeal arches and that produce the neuroblasts that migrate and condense to form the distal cranial ganglia.
Epimysium is a layer of connective tissue which ensheaths the entire muscle. It is composed of dense irregular connective tissue. It is continuous with fascia and other connective tissue wrappings of muscle including the endomysium, and perimysium. It is also continuous with tendons where it becomes thicker and collagenous.
Epithelial tubes transport gases, liquids and cells from one site to another and form the basic structure of many organs and tissues, with tube shape and organization varying from the single-celled excretory organ in Caenorhabditis elegans to the branching trees of the mammalian kidney and insect tracheal system.
Portion of tissue, that consists of one or more layers of epithelial cells connected to each other by cell junctions and which is underlain by a basal lamina. Examples: simple squamous epithelium, glandular cuboidal epithelium, transitional epithelium, myoepithelium[CARO]. Editor note: surface epithelium may contain non-epithelial cells, such as melanocytes, lymphocytes and dendritic cells, within the sheet of epithelial cells. Do we consider these part of the epithelium, or located-in it?