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Common Cardinal Vein
The common cardinal veins, also known as the ducts of Cuvier, are veins that drain into the sinus venosus during embryonic development. These drain an anterior cardinal vein and a posterior cardinal vein on each ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinus Venosus
The sinus venosus is a large quadrangular cavity which precedes the atrium on the venous side of the chordate heart. In mammals, the sinus venosus exists distinctly only in the embryonic heart where it is found between the two venae cavae; in the adult, the sinus venosus becomes incorporated into the wall of the right atrium to form a smooth part called the sinus venarum which is separated from the rest of the atrium by a ridge called the crista terminalis. In most mammals, the sinus venosus also forms the sinoatrial node and the coronary sinus. Development In the embryo, the thin walls of the sinus venosus are connected below with the right ventricle, and medially with the left atrium, but are free in the rest of their extent. It receives blood from the vitelline vein, umbilical vein and common cardinal vein The common cardinal veins, also known as the ducts of Cuvier, [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryonic Development
In developmental biology, animal embryonic development, also known as animal embryogenesis, is the developmental stage of an animal embryo. Embryonic development starts with the fertilization of an egg cell (ovum) by a sperm, sperm cell (spermatozoon). Once fertilized, the ovum becomes a single diploid cell known as a zygote. The zygote undergoes mitosis, mitotic cell division, divisions with no significant growth (a process known as cleavage (embryo), cleavage) and cellular differentiation, leading to development of a multicellular embryo after passing through an organizational checkpoint during mid-embryogenesis. In mammals, the term refers chiefly to the early stages of prenatal development, whereas the terms fetus and fetal development describe later stages. The main stages of animal embryonic development are as follows: * The zygote undergoes a series of cell divisions (called cleavage) to form a structure called a morula. * The morula develops into a structure called a bla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anterior Cardinal Vein
The anterior cardinal veins (precardinal veins) contribute to the formation of the internal jugular veins and together with the common cardinal vein form the superior vena cava. The anastomosis between the two anterior cardinal veins develops into the left brachiocephalic vein. Additional images Image:Gray459.png, Human embryo Human embryonic development or human embryogenesis is the development and formation of the human embryo. It is characterised by the processes of cell division and cellular differentiation of the embryo that occurs during the early stages of deve ... of about fourteen days, with yolk sac. See also * Posterior cardinal vein References External links * Diagram at nature.com Embryology of cardiovascular system {{circulatory-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Cardinal Vein
The posterior cardinal veins or postcardinal veins join with the corresponding right and left cardinal veins to form the left common cardinal veins, which empty in the sinus venosus. In the development of a human embryo, most of the posterior cardinal veins regress, and what remains of them forms the renal segment of the inferior vena cava and the common iliac veins. Later in the development stages, the posterior cardinal veins are replaced by the subcardinal and supracardinal veins. The subcardinal veins form part of the inferior vena cava, the renal veins and the gonadal veins. The supracardinal veins form part of the inferior vena cava, the intercostal veins, the hemiazygos vein and the azygos vein. Henry Gray (1918). Anatomy of the Human Body, page 520. Additional images File:Gray459.png, Human embryo of about fourteen days, with yolk-sac. See also * Anterior cardinal vein The anterior cardinal veins (precardinal veins) contribute to the formation of the internal jug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolffian Bodies
The mesonephros () is one of three excretory organs that develop in vertebrates. It serves as the main excretory organ of aquatic vertebrates and as a temporary kidney in reptiles, birds, and mammals. The mesonephros is included in the Wolffian body after Caspar Friedrich Wolff who described it in 1759. (The Wolffian body is composed of: mesonephros + paramesonephrotic blastema) Structure The mesonephros acts as a structure similar to the kidney that, in humans, functions between the sixth and tenth weeks of embryological life. Despite the similarity in structure, function, and terminology, however, the mesonephric nephrons do not form any part of the mature kidney or nephrons. In humans, the mesonephros consists of units which are similar in structure and function to nephrons of the adult kidney. Each of these consists of a glomerulus, a tuft of capillaries which arises from lateral branches of dorsal aorta and drains into the inferior cardinal vein; a Bowman's capsule, a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Cardinal Vein
The posterior cardinal veins or postcardinal veins join with the corresponding right and left cardinal veins to form the left common cardinal veins, which empty in the sinus venosus. In the development of a human embryo, most of the posterior cardinal veins regress, and what remains of them forms the renal segment of the inferior vena cava and the common iliac veins. Later in the development stages, the posterior cardinal veins are replaced by the subcardinal and supracardinal veins. The subcardinal veins form part of the inferior vena cava, the renal veins and the gonadal veins. The supracardinal veins form part of the inferior vena cava, the intercostal veins, the hemiazygos vein and the azygos vein. Henry Gray (1918). Anatomy of the Human Body, page 520. Additional images File:Gray459.png, Human embryo of about fourteen days, with yolk-sac. See also * Anterior cardinal vein The anterior cardinal veins (precardinal veins) contribute to the formation of the internal jug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Sinus
The coronary sinus () is the largest vein of the heart. It drains over half of the deoxygenated blood from the heart muscle into the right atrium. It begins on the backside of the heart, in between the left atrium, and left ventricle; it begins at the junction of the great cardiac vein, and oblique vein of the left atrium. It receives multiple tributaries. It passes across the backside of the heart along a groove between left atrium and left ventricle, then drains into the right atrium at the orifice of the coronary sinus (which is usually guarded by the valve of coronary sinus). Structure Origin The coronary sinus arises upon the posterior aspect of the heart between the left atrium, and left ventricle. The coronary sinus commences at the union of the great cardiac vein, and the oblique vein of the left atrium. The origin of the coronary sinus is marked by the Vieussens valve of the coronary sinus which is situated at the endpoint of the great cardiac vein. Cour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georges Cuvier
Jean Léopold Nicolas Frédéric, baron Cuvier (23 August 1769 – 13 May 1832), known as Georges Cuvier (; ), was a French natural history, naturalist and zoology, zoologist, sometimes referred to as the "founding father of paleontology". Cuvier was a major figure in natural sciences research in the early 19th century and was instrumental in establishing the fields of comparative anatomy and paleontology through his work in comparing living animals with fossils. Cuvier's work is considered the foundation of vertebrate paleontology, and he expanded Linnaean taxonomy by grouping classes into phylum, phyla and incorporating both fossils and living species into the classification. Cuvier is also known for establishing extinction as a fact—at the time, extinction was considered by many of Cuvier's contemporaries to be merely controversial speculation. In his ''Essay on the Theory of the Earth'' (1813) Cuvier proposed that now-extinct species had been wiped out by periodic catastr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
