Anatomical terminology is a form of scientific terminology used by anatomists and health professionals such as doctors. Anatomical terminology uses many unique terms 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. Since these anatomical terms are not used in everyday conversation, their meanings are less to change, less 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. 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 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, 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, frons, auris, nasus and mentum. The neck area is called 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, is used when describing the skull.
Different terminology is 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: Radial referring to the radius bone, seen laterally in the standard anatomical position. Ulnar referring to the ulna bone, medially positioned when in the standard anatomical position. Other terms are used to describe the movement and actions of the hands and feet, 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 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 functional.
It covers the gross anatomy and the microscopic of living beings. It involves the anatomy of the adult, it includes comparative anatomy between different species. The vocabulary is extensive and complex, requires a systematic presentation. Within the international field, a group of experts reviews and discusses the morphological terms of the structures of the human body, forming today's Terminology Committee from the International Federation of Associations of Anatomists, it deals with the anatomical and embryologic terminology. In the Latin American field, there are meetings called Iberian Latin American Symposium Terminology, where a group of experts of the Pan American Association of Anatomy that speak Spanish and Portuguese and studies the international morphological terminology; the current international standard for human anatomical terminology is based on the Terminologia Anatomica. It was developed by the Federative Committee on Anatomical Terminology and the International Federation of Associations of Anatomists and was released in 1998.
It supersedes Nomina Anatomica. Terminologia Anatomica contains terminology for about 7500 human gross anatomical structures. For microanatomy, known as histology, a similar standard exists in Terminologia Histologica, for embryology, the study of development, a standard exists in Terminologia Embryologica; these standards specify accepted names that can be used to refer to histological and embryological structures in journal articles 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; the Terminologia Anatomica has been perceived with a considerable criticism regarding its content including coverage and spelling mistakes and errors. Anatomical terminology is 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
The public domain consists of all the creative works to which no exclusive intellectual property rights apply. Those rights may have been forfeited, expressly waived, or may be inapplicable; the works of William Shakespeare and Beethoven, most early silent films, are in the public domain either by virtue of their having been created before copyright existed, or by their copyright term having expired. Some works are not covered by copyright, are therefore in the public domain—among them the formulae of Newtonian physics, cooking recipes, all computer software created prior to 1974. Other works are dedicated by their authors to the public domain; the term public domain is not applied to situations where the creator of a work retains residual rights, in which case use of the work is referred to as "under license" or "with permission". As rights vary by country and jurisdiction, a work may be subject to rights in one country and be in the public domain in another; some rights depend on registrations on a country-by-country basis, the absence of registration in a particular country, if required, gives rise to public-domain status for a work in that country.
The term public domain may be interchangeably used with other imprecise or undefined terms such as the "public sphere" or "commons", including concepts such as the "commons of the mind", the "intellectual commons", the "information commons". Although the term "domain" did not come into use until the mid-18th century, the concept "can be traced back to the ancient Roman Law, as a preset system included in the property right system." The Romans had a large proprietary rights system where they defined "many things that cannot be owned" as res nullius, res communes, res publicae and res universitatis. The term res nullius was defined as things not yet appropriated; the term res communes was defined as "things that could be enjoyed by mankind, such as air and ocean." The term res publicae referred to things that were shared by all citizens, the term res universitatis meant things that were owned by the municipalities of Rome. When looking at it from a historical perspective, one could say the construction of the idea of "public domain" sprouted from the concepts of res communes, res publicae, res universitatis in early Roman law.
When the first early copyright law was first established in Britain with the Statute of Anne in 1710, public domain did not appear. However, similar concepts were developed by French jurists in the 18th century. Instead of "public domain", they used terms such as publici juris or propriété publique to describe works that were not covered by copyright law; the phrase "fall in the public domain" can be traced to mid-19th century France to describe the end of copyright term. The French poet Alfred de Vigny equated the expiration of copyright with a work falling "into the sink hole of public domain" and if the public domain receives any attention from intellectual property lawyers it is still treated as little more than that, left when intellectual property rights, such as copyright and trademarks, expire or are abandoned. In this historical context Paul Torremans describes copyright as a, "little coral reef of private right jutting up from the ocean of the public domain." Copyright law differs by country, the American legal scholar Pamela Samuelson has described the public domain as being "different sizes at different times in different countries".
Definitions of the boundaries of the public domain in relation to copyright, or intellectual property more regard the public domain as a negative space. According to James Boyle this definition underlines common usage of the term public domain and equates the public domain to public property and works in copyright to private property. However, the usage of the term public domain can be more granular, including for example uses of works in copyright permitted by copyright exceptions; such a definition regards work in copyright as private property subject to fair-use rights and limitation on ownership. A conceptual definition comes from Lange, who focused on what the public domain should be: "it should be a place of sanctuary for individual creative expression, a sanctuary conferring affirmative protection against the forces of private appropriation that threatened such expression". Patterson and Lindberg described the public domain not as a "territory", but rather as a concept: "here are certain materials – the air we breathe, rain, life, thoughts, ideas, numbers – not subject to private ownership.
The materials that compose our cultural heritage must be free for all living to use no less than matter necessary for biological survival." The term public domain may be interchangeably used with other imprecise or undefined terms such as the "public sphere" or "commons", including concepts such as the "commons of the mind", the "intellectual commons", the "information commons". A public-domain book is a book with no copyright, a book, created without a license, or a book where its copyrights expired or have been forfeited. In most countries the term of protection of copyright lasts until January first, 70 years after the death of the latest living author; the longest copyright term is in Mexico, which has life plus 100 years for all deaths since July 1928. A notable exception is the United States, where every book and tale published prior to 1924 is in the public domain.
The truncus arteriosus is a structure, present during embryonic development. It is an arterial trunk that originates from both ventricles of the heart that divides into the aorta and the pulmonary trunk; the truncus arteriosus and bulbus cordis are divided by the aorticopulmonary septum. The truncus arteriosus gives rise to the pulmonary trunk; the caudal end of the bulbus cordis gives rise to the smooth parts of the left and right ventricles. The cranial end of the bulbus cordis gives rise to the aorta and pulmonary trunk with the truncus arteriosus; this makes its appearance in three portions. Two distal ridge-like thickenings project into the lumen of the tube: the truncal and bulbar ridges; these increase in size, meet and fuse to form a septum, which takes a spiral course toward the proximal end of the truncus arteriosus. It divides the distal part of the truncus into two vessels, the aorta and pulmonary artery, which lie side by side above, but near the heart the pulmonary artery is in front of the aorta.
Four endocardial cushions appear in the proximal part of the truncus arteriosus in the region of the future semilunar valves. Two endocardial thickenings—anterior and posterior—develop in the bulbus cordis and unite to form a short septum; the septum grows down into the ventricle as an oblique partition, which blends with the ventricular septum in such a way as to bring the bulbus cordis into communication with the pulmonary artery, through the latter with the sixth pair of aortic arches. Failure of the truncus arteriosus to close results in the condition known as persistent truncus arteriosus, a rare congenital heart defect; this is just referred to as truncus arteriosus. Other pathologies of the truncus arteriosus include transposition of the great vessels, tetralogy of Fallot; this article incorporates text in the public domain from page 514 of the 20th edition of Gray's Anatomy Truncus Arteriosus - Stanford Children's Health Embryology at UNSW Notes/heart3b Overview at mcgill.ca Description and diagram at umich.edu
The umbilical vein is a vein present during fetal development that carries oxygenated blood from the placenta into the growing fetus. The umbilical vein provides convenient access to the central circulation of a neonate for restoration of blood volume and for administration of glucose and drugs; the blood pressure inside the umbilical vein is 20 mmHg. The unpaired umbilical vein carries oxygen and nutrient rich blood derived from fetal-maternal blood exchange at the chorionic villi. More than two-thirds of fetal hepatic circulation is via the main portal vein, while the remainder is shunted from the left portal vein via the ductus venosus to the inferior vena cava being delivered to the fetal right atrium. Closure of the umbilical vein occurs after the umbilical arteries have closed; this prolongs the communication between the placenta and fetal heart, allowing for a sort of autotransfusion of remaining blood from the placenta to the fetus. Within a week of birth, the neonate's umbilical vein is obliterated and is replaced by a fibrous cord called the round ligament of the liver.
It extends from the umbilicus to the transverse fissure, where it joins with the falciform ligament of the liver to separate segment 4 from segments 2 and 3 of the left hepatic lobe. Under extreme pressure, the round ligament may reopen to allow the passage of blood; such recanalization may be evident in patients with cirrhosis and portal hypertension. Patients with cirrhosis experience rapid growth of scar tissue in and around the liver functionally obstructing nearby vessels. Vessel occlusion increases therefore leads to hypertension. In portal hypertension, the vessels surrounding the liver are subjected to abnormally high blood pressure—so high, in fact, that the force of the blood pressing against the round ligament is sufficient to recanalize the structure; this leads to a condition called Caput medusae. A newborn baby has a patent umbilical vein for at least a week after birth; this umbilical vein may be catheterised for ready intravenous access. It may be used as a site for regular transfusion in cases of hemolytic disease.
It provides a route for measuring central venous pressure. Human umbilical vein graft Ductus venosus Gray's s139 - "Peculiarities in the vascular system of the fetus" Embryology at Temple Heart98/heart97a/sld020
The tubular heart or primitive heart tube is the earliest stage of heart development. From the inflow to the outflow, it consists of sinus venosus, primitive atrium, the primitive ventricle, the bulbus cordis, truncus arteriosus, it forms from splanchnic mesoderm. More they form from endocardial tubes, starting at day 21. Embryology at Temple Heart98/heart97a/sld018 Embryology at Temple Heart98/heart97a/sld019
In animals that give live birth, the fetal circulation is the circulatory system of a fetus. The term encompasses the entire fetoplacental circulation, which includes the umbilical cord and the blood vessels within the placenta that carry fetal blood; the fetal circulation works differently from normal postnatal circulation because the lungs are not in use. Instead, the fetus obtains oxygen and nutrients from the mother through the placenta and the umbilical cord; the advent of breathing and the severance of the umbilical cord prompt various neuroendocrine changes that shortly transform fetal circulation into postnatal circulation. The fetal circulation of humans has been extensively studied by the health sciences. Much is known of fetal circulation in other animals livestock and model organisms such as mice, through the health sciences, veterinary science, life sciences generally. Blood from the placenta is carried to the fetus by the umbilical vein. In humans, less than a third of this enters the fetal ductus venosus and is carried to the inferior vena cava, while the rest enters the liver proper from the inferior border of the liver.
The branch of the umbilical vein that supplies the right lobe of the liver first joins with the portal vein. The blood moves to the right atrium of the heart. In the fetus, there is an opening between the right and left atrium, most of the blood flows through this hole directly into the left atrium from the right atrium, thus bypassing pulmonary circulation; the continuation of this blood flow is into the left ventricle, from there it is pumped through the aorta into the body. Some of the blood moves from the aorta through the internal iliac arteries to the umbilical arteries, re-enters the placenta, where carbon dioxide and other waste products from the fetus are taken up and enter the maternal circulation; some of the blood entering the right atrium does not pass directly to the left atrium through the foramen ovale, but enters the right ventricle and is pumped into the pulmonary artery. In the fetus, there is a special connection between the pulmonary artery and the aorta, called the ductus arteriosus, which directs most of this blood away from the lungs.
The circulatory system of the mother is not directly connected to that of the fetus, so the placenta functions as the respiratory center for the fetus as well as a site of filtration for plasma nutrients and wastes. Water, amino acids and inorganic salts diffuse across the placenta along with oxygen; the uterine arteries carry blood to the placenta, the blood permeates the sponge-like material there. Oxygen diffuses from the placenta to the chorionic villus, an alveolus-like structure, where it is carried to the umbilical vein; the circulatory system, consisting of the heart and blood vessels, forms early during embryonic development, continues to develop in complexity within the growing fetus. A functional circulatory system is a biological necessity, since mammalian tissues can not grow more than a few cell layers thick without an active blood supply; the prenatal circulation of blood is different than the postnatal circulation because the lungs are not in use. The fetus obtains oxygen and nutrients from the mother through the umbilical cord.
Blood from the placenta is carried to the fetus by the umbilical vein. About half of this enters the fetal ductus venosus and is carried to the inferior vena cava, while the other half enters the liver proper from the inferior border of the liver; the branch of the umbilical vein that supplies the right lobe of the liver first joins with the portal vein. The blood moves to the right atrium of the heart. In the fetus, there is an opening between the right and left atrium, most of the blood flows from the right into the left atrium, thus bypassing pulmonary circulation; the majority of blood flow is into the left ventricle from where it is pumped through the aorta into the body. Some of the blood moves from the aorta through the internal iliac arteries to the umbilical arteries, re-enters the placenta, where carbon dioxide and other waste products from the fetus are taken up and enter the woman's circulation; some of the blood from the right atrium does not enter the left atrium, but enters the right ventricle and is pumped into the pulmonary artery.
In the fetus, there is a special connection between the pulmonary artery and the aorta, called the ductus arteriosus, which directs most of this blood away from the lungs. At birth, when the infant breathes for the first time, there is a decrease in the resistance in the pulmonary vasculature, which causes the pressure in the left atrium to increase relative to the pressure in the right atrium; this leads to the closure of the foramen ovale, referred to as the fossa ovalis. Additionally, the increase in the concentration of oxygen in the blood leads to a decrease in prostaglandins, causing closure of the ductus arteriosus; these closures prevent blood from bypassing pulmonary circulation, therefore allow the neonate's blood to become oxygenated in the newly operational lungs. Sometimes these postnatal closures are absent; the vessels or cross-connections remain open, leading to the following conditions: Patent foramen ovale in the heart Patent ductus arteriosus in the great vessels Patent ductus venosus in the great vessels Remnants of the fetal circulation can be found in the adult.
In addition to differences in circulation, the developing fetus employs a different type of oxyg
Vascular remodelling in the embryo
Vascular remodelling is a process which begins at day 21 of human embryogenesis, when an immature heart begins contracting, pushing fluid through the early vasculature. This first passage of fluid initiates a signal cascade based on physical cues including shear stress and circumferential stress, necessary for the remodelling of the vascular network, arterial-venous identity and the regulation of genes through mechanotransduction; this embryonic process is necessary for the future stability of the mature vascular network. Vasculogenesis is the initial establishment of the components of the blood vessel network, or vascular tree; this is dictated by genetic factors and has no inherent function other than to lay down the preliminary outline of the circulatory system. Once fluid flow begins and hemodynamic inputs are applied to the system set up by vasculogenesis, the active remodelling process can begin. Physical cues such as pressure, flow patterns, shear stress are known to act on the vascular network in a number of ways, including branching morphogenesis, enlargement of vessels in high-flow areas and the development of vein valves.
The mechanotransduction of these physical cues to endothelial and smooth muscle cells in the vascular wall can trigger the promotion or repression of certain genes which are responsible for vasodilation, cell alignment, other shear stress-mitigating factors. This relationship between genetics and environment is not understood, but researchers are attempting to clarify it by combining reliable genetic techniques, such as genetically-ablated model organisms and tissues, with new technologies developed to measure and track flow patterns, velocity profiles, pressure fluctuations in vivo. Both in vivo study and modelling are necessary tools to understand this complex process. Vascular remodelling is pertinent to wound healing and proper integration of tissue grafts and organ donations. Promoting an active remodelling process in some cases could help patients recover faster and retain functional use of donated tissues. However, outside of wound healing, chronic vascular remodelling in the adult is symptomatic of cardiovascular disease.
Thus, increased understanding of this biomedical phenomenon could aid in the development of therapeutics or preventative measures to combat diseases such as atherosclerosis. The study of vascular remodelling in the embryo is believed to have been pioneered by Thoma in 1893 when he observed that increases in local blood flow cause widening of the vessel diameter going so far as to postulate that blood flow might be responsible for the growth and development of blood vessels. Subsequently, Chapman in 1918 discovered that removing a chick embryo’s heart disrupted the remodelling process, but the initial vessel patterns laid down by vasculogenesis remained undisturbed. Next, in 1926 Murray proposed that vessel diameter was proportional to the amount of shear stress at the vessel wall; the famous text "The chemical basis of morphogenesis," written in 1952 by mathematician and computer scientist Alan Turing advocated for various biological models based on molecular diffusion of nutrients. However, a diffusive model of vascular development would seem to fall short of the complexity of capillary beds and the interwoven network of arteries and veins.
In 2000, Fleury proposed that instead of diffusive molecules bearing responsibility for the branching morphogenesis of the vascular tree, a long-range morphogen may be implicated. In this model, a traveling pressure wave would act upon the vasculature via shear stress to rearrange branches into the lowest-energy configuration by widening vessels carrying increased blood flow and rearranging networks upon the initiation of fluid flow, it is known that mechanical forces can have a dramatic impact on the morphology and complexity of the vascular tree. However, these forces have comparably little impact on the diffusion of nutrients, it therefore seems unlikely that acquisition of nutrients and oxygen plays a significant role in embryonic vascular remodelling, it is now accepted that vascular remodelling in the embryo is a process distinct from vasculogenesis. Vasculogenesis occurs prior to vascular remodelling, but is a necessary step in the development of the blood vessel network and has implications on the identification of vessels as either arterial or venous.
Once contraction of the heart begins, vascular remodelling progresses via the interplay of forces resulting from biomechanical cues and fluid dynamics, which are translated by mechanotransduction to changes at cellular and genetic levels. Vasculogenesis is the formation of early vasculature, laid down by genetic factors. Structures called blood islands form in the mesoderm layer of the yolk sac by cellular differentiation of hemangioblasts into endothelial and red blood cells. Next, the capillary plexus forms as endothelial cells migrate outward from blood islands and form a random network of continuous strands; these strands undergo a process called lumenization, the spontaneous rearrangement of endothelial cells from a solid cord into a hollow tube. Inside the embryo, the dorsal aorta forms and connect the heart to the capillary plexus of the yolk sac; this forms a closed-loop system of rigid endothelial tubing. It is known that this early in the process of vasculogenesis, before the onset of blood flow, sections of the tube system may express ephrins or neuropilins, genetic markers of arterial or venous identities, respectively.
These identities are still somewhat flexible, but the initial characterization is important