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Sinus Venosus
The sinus venosus is a large quadrangular cavity which precedes the atrium on the venous side of the chordate heart. In mammals, it exists distinctly only in the embryonic heart, where it is found between the two venae cavae. However, the sinus venosus persists in the adult. In the adult, it is 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 of fibres called the crista terminalis. The sinus venosus also forms the sinoatrial node and the coronary sinus; in (most) mammals only. 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 sinus venosus originally starts as a paired structure but shifts towards associating only with the right atrium as the embryonic heart develops. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatomical Terms Of Location
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and anatomical axes. The meaning of terms that are used can change depending on whether an organism is bipedal or quadrupedal. Additionally, for some animals such as invertebrates, some terms may not have any meaning at all; for example, an animal that is radially symmetrical will have no anterior surface, but can still have a description that a part is close to the middle ("proximal") or further from the middle ("distal"). International organisations have determined vocabularies that are often used as standard vocabularies for subdisciplines of anatom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umbilical Vein
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 approximately 20 mmHg.Wang, Y. Vascular biology of the placenta. in Colloquium Series on Integrated Systems Physiology: from Molecule to Function. 2010. Morgan & Claypool Life Sciences. Fetal circulation 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, eventually being delivered to the fetal right atrium. Closure Closure of the umbilical vein usually occurs after the umbilica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryology Of Cardiovascular System
Embryology (from Greek ἔμβρυον, ''embryon'', "the unborn, embryo"; and -λογία, ''-logia'') is the branch of animal biology that studies the prenatal development of gametes (sex cells), fertilization, and development of embryos and fetuses. Additionally, embryology encompasses the study of congenital disorders that occur before birth, known as teratology. Early embryology was proposed by Marcello Malpighi, and known as preformationism, the theory that organisms develop from pre-existing miniature versions of themselves. Aristotle proposed the theory that is now accepted, epigenesis. Epigenesis is the idea that organisms develop from seed or egg in a sequence of steps. Modern embryology, developed from the work of Karl Ernst von Baer, though accurate observations had been made in Italy by anatomists such as Aldrovandi and Leonardo da Vinci in the Renaissance. Comparative embryology Preformationism and epigenesis As recently as the 18th century, the prevailing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinus Venosus Atrial Septal Defect
A sinus venosus atrial septal defect is a type of atrial septal defect primarily associated with the sinus venosus. They represent 5% of atrial septal defects.Robbins and Cotran Pathologic Basis of Disease 8th Edition They can occur near the superior vena cava or inferior vena cava, but the former are more common. They can be associated with anomalous pulmonary venous connection Anomalous pulmonary venous connection (or anomalous pulmonary venous drainage or anomalous pulmonary venous return) is a congenital defect of the pulmonary veins. Total anomalous pulmonary venous connection ''Total anomalous pulmonary venous con .... References External links {{Congenital heart defects Congenital heart defects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Truncus Arteriosus (embryology)
The truncus arteriosus is a structure that is present during embryonic development. It is an arterial trunk that originates from both ventricles of the heart that later divides into the aorta and the pulmonary trunk. Structure The truncus arteriosus and bulbus cordis are divided by the aorticopulmonary septum. The truncus arteriosus gives rise to the ascending aorta and the pulmonary trunk. The caudal end of the bulbus cordis gives rise to the smooth parts (outflow tract) of the left and right ventricles (aortic vestibule & conus arteriosus respectively). The cranial end of the bulbus cordis (also known as the conus 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, and ultimately meet and fuse to form a septum ( aorticopulmonary septum), which takes a spiral course toward the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ductus Venosus
In the fetus, the ''ductus venosus'' (Arantius' duct after Julius Caesar Aranzi) shunts a portion of umbilical vein blood flow directly to the inferior vena cava. Thus, it allows oxygenated blood from the placenta to bypass the liver. Compared to the 50% shunting of umbilical blood through the ''ductus venosus'' found in animal experiments, the degree of shunting in the human fetus under physiological conditions is considerably less, 30% at 20 weeks, which decreases to 18% at 32 weeks, suggesting a higher priority of the fetal liver than previously realized. In conjunction with the other fetal shunts, the ''foramen ovale'' and ''ductus arteriosus'', it plays a critical role in preferentially shunting oxygenated blood to the fetal brain. It is a part of fetal circulation. Anatomic course The pathway of fetal umbilical venous flow is umbilical vein to left portal vein to ''ductus venosus'' to ''inferior vena cava'' and eventually the right atrium. This anatomic course is important i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primitive Atrium
The primitive atrium is a stage in the embryonic development of the human heart. It grows rapidly and partially encircles the bulbus cordis; the groove against which the bulbus cordis lies is the first indication of a division into right and left atria. The cavity of the primitive atrium becomes subdivided into right and left chambers by a septum, the septum primum, which grows downward into the cavity. For a time the atria communicate with each other by an opening, the primary interatrial foramen, below the free margin of the septum. This opening is closed by the union of the septum primum with the septum intermedium, and the communication between the atria is re-established through an opening which is developed in the upper part of the septum primum; this opening is known as the foramen ovale (ostium secundum of Born) and persists until birth. A second septum, the septum secundum, semilunar in shape, grows downward from the upper wall of the atrium immediately to the right of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primitive Ventricle
The primitive ventricle or embryonic ventricle of the developing heart, together with the bulbus cordis that lies in front of it, gives rise to the left and right ventricles. The primitive ventricle provides the trabeculated parts of the walls, and the bulbus cordis the smooth parts. The primitive ventricle becomes divided by the septum inferius which develops into the interventricular septum. The septum grows upward from the lower part of the ventricle, at a position marked on the heart's surface by a furrow. Its dorsal part increases more rapidly than its ventral portion, and fuses with the dorsal part of the septum intermedium. For a time an interventricular foramen exists above its ventral portion, but this foramen is ultimately closed by the fusion of the aortic septum 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 se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ducts Of Cuvier
The common cardinal veins, also known as the ducts of Cuvier, are veins that drain into the during . These drain an and a |
Bulbus Cordis
The bulbus cordis (the bulb of the heart) is a part of the developing heart that lies ventral to the primitive ventricle after the heart assumes its S-shaped form. The superior end of the bulbus cordis is also called the conotruncus. Structure In the early tubular heart, the bulbus cordis is the major outflow pathway. It receives blood from the primitive ventricle, and passes it to the truncus arteriosus. After heart looping, it is located slightly to the left of the ventricle. Development The early bulbus cordis is formed by the fifth week of development. The truncus arteriosus is derived from it later. The adjacent walls of the bulbus cordis and ventricle approximate, fuse, and finally disappear, and the bulbus cordis now communicates freely with the right ventricle, while the junction of the bulbus with the truncus arteriosus is brought directly ventral to and applied to the atrial canal. By the upgrowth of the ventricular septum the bulbus cordis is separated from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atrial Septal Defect
Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria (upper chambers) of the heart. Some flow is a normal condition both pre-birth and immediately post-birth via the foramen ovale; however, when this does not naturally close after birth it is referred to as a patent (open) foramen ovale (PFO). It is common in patients with a congenital atrial septal aneurysm (ASA). After PFO closure the atria normally are separated by a dividing wall, the interatrial septum. If this septum is defective or absent, then oxygen-rich blood can flow directly from the left side of the heart to mix with the oxygen-poor blood in the right side of the heart; or the opposite, depending on whether the left or right atrium has the higher blood pressure. In the absence of other heart defects, the left atrium has the higher pressure. This can lead to lower-than-normal oxygen levels in the arterial blood that supplies the brain, organs, and tissues. However, an ASD m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oblique Vein
The oblique vein of the left atrium (oblique vein of Marshall) is a small vessel which descends obliquely on the back of the left atrium and ends in the coronary sinus near its left extremity; it is continuous above with the ligament of the left vena cava (lig. venæ cavæ sinistræ vestigial fold of Marshall), and the two structures form the remnant of the left Cuvierian duct The common cardinal veins, also known as the ducts of Cuvier, [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
