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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] |
Cardiovascular System
In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek meaning ''heart'', and Latin meaning ''vessels''). The circulatory system has two divisions, a systemic circulation or circuit, and a pulmonary circulation or circuit. Some sources use the terms ''cardiovascular system'' and ''vascular system'' interchangeably with ''circulatory system''. The network of blood vessels are the great vessels of the heart including large elastic arteries, and large veins; other arteries, smaller arterioles, capillaries that join with venules (small veins), and other veins. The circulatory system is closed in vertebrates, which means that the blood never leaves the network of blood vessels. Many invertebrates such as arthropods have an open circulatory system with a heart ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Cardinal Veins
The common cardinal veins, also known as the ducts of Cuvier, are veins that drain into the during . These drain an and a |
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] |
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 development. In biological terms, the development of the human body entails growth from a one-celled zygote to an adult human being. Human fertilization, Fertilization occurs when the Spermatozoon, sperm cell successfully enters and Cell fusion, fuses with an egg cell (ovum). The genetic material of the sperm and egg then combine to form the single cell zygote and the germinal stage of development commences. Human embryonic development covers the first eight weeks of development, which have 23 stages, called Carnegie stages. At the beginning of the ninth week, the embryo is termed a fetus (spelled "foetus" in British English). In comparison to the embryo, the fetus has more recognizable external features and a more complete set of developing o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Vena Cava
The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of the fifth Lumbar vertebrae, lumbar vertebra. The inferior vena cava is the lower ("anatomical terms of location#Superior and inferior, inferior") of the two venae cavae, the two large veins that carry deoxygenated blood from the body to the right atrium of the heart: the inferior vena cava carries blood from the lower half of the body whilst the superior vena cava carries blood from the upper half of the body. Together, the venae cavae (in addition to the coronary sinus, which carries blood from the muscle of the heart itself) form the venous counterparts of the aorta. It is a large retroperitoneal vein that lies Posterior (anatomy), posterior to the abdominal cavity and runs along the right side of the vertebral column. It enters the right a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Iliac Veins
In human anatomy, the common iliac veins are formed by the external iliac veins and internal iliac veins. The left and right common iliac veins come together in the abdomen at the level of the fifth lumbar vertebra, forming the inferior vena cava. They drain blood from the pelvis and lower limbs. Both common iliac veins are accompanied along their course by common iliac arteries. Structure The external iliac vein and internal iliac vein unite in front of the sacroiliac joint to form the common iliac veins. Both common iliac veins ascend to form the inferior vena cava behind the right common iliac artery at the level of the fifth lumbar vertebra. The vena cava is to the right of the midline and therefore the left common iliac vein is longer than the right. The left common iliac vein occasionally travels upwards to the left of the aorta to the level of the kidney, where it receives the left renal vein and crosses in front of the aorta to join the inferior vena cava. The right ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renal Vein
The renal veins in the renal circulation, are large-calibre veins that drain blood filtered by the kidneys into the inferior vena cava. There is one renal vein draining each kidney. Each renal vein is formed by the convergence of the interlobar veins of one kidney. Because the inferior vena cava is on the right half of the body, the left renal vein is longer than the right one. Structure One renal vein drains each kidney. A renal vein is situated anterior to its corresponding accompanying renal artery. The renal veins empty into the inferior vena cava, entering it at nearly a 90° angle. Due to the right-ward displacement of the inferior vena cava from the midline, the left renal vein is some 3 times longer than the right one (~7.5 cm and ~2.5 cm, respectively). The renal vein divides into 4 divisions upon entering the kidney: * the anterior branch which receives blood from the anterior portion of the kidney and, * the posterior branch which receives blood from the posterior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonadal Vein
A gonad, sex gland, or reproductive gland is a mixed gland and sex organ that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sperm in the form of spermatozoa. The female gonad, the ovary, produces egg cells. Both of these gametes are haploid cells. Some hermaphroditic animals (and some humanssee Ovotesticular syndrome) have a type of gonad called an ovotestis. Evolution It is hard to find a common origin for gonads, but gonads most likely evolved independently several times. Regulation The gonads are controlled by luteinizing hormone (LH) and follicle-stimulating hormone (FSH), produced and secreted by gonadotropes or gonadotrophins in the anterior pituitary gland. This secretion is regulated by gonadotropin-releasing hormone (GnRH) produced in the hypothalamus. Development The gonads develop from three sources; the mesothelium, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemiazygos Vein
The hemiazygos vein (vena azygos minor inferior) is a vein running superiorly in the lower thoracic region, just to the left side of the vertebral column. Structure The hemiazygos vein and the accessory hemiazygos vein, when taken together, essentially serve as the left-sided equivalent of the azygos vein. That is, the azygos vein serves to drain most of the posterior intercostal veins on the right side of the body, and the hemiazygos vein and the accessory hemiazygos vein drain most of the posterior intercostal veins on the left side of the body. Specifically, the hemiazygos vein mirrors the bottom part of the azygos vein. The structure of the hemiazygos vein is often variable. It usually begins in the left ascending lumbar vein or renal vein, and passes upward through the left crus of the diaphragm to enter the thorax. It continues ascending on the left side of the vertebral column, and around the level of the ninth thoracic vertebra, it passes rightward across the column, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azygos Vein
The azygos vein (from Ancient Greek ἄζυγος (ázugos), meaning 'unwedded' or 'unpaired') is a vein running up the right side of the thoracic vertebral column draining itself towards the superior vena cava. It connects the systems of superior vena cava and inferior vena cava and can provide an alternative path for blood to the right atrium when either of the venae cavae is blocked. Structure The azygos vein transports deoxygenated blood from the posterior walls of the thorax and abdomen into the superior vena cava. It is formed by the union of the ascending lumbar veins with the right subcostal veins at the level of the 12th thoracic vertebra, ascending to the right of the descending aorta and thoracic duct, passing behind the right crus of diaphragm, anterior to the vertebral bodies of T12 to T5 and right posterior intercostal arteries. At the level of T4 vertebrae, it arches over the root of the right lung from behind to the front to join the superior vena cava. The tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Gray
Henry Gray (1827 – 13 June 1861) was a British anatomist and surgery, surgeon most notable for publishing the book ''Gray's Anatomy''. He was elected a Fellow of the Royal Society (FRS) at the age of 25. Biography Gray was born in Belgravia, London, in 1827 and lived most of his life in London. In 1842, he entered as a student at St George's Hospital, St. George's Hospital, London (then situated in Belgravia, now moved to Tooting), and he is described by those who knew him as a most painstaking and methodical worker, and one who learned his anatomy by the slow but invaluable method of making dissections for himself. While still a student, Gray secured the triennial prize of Royal College of Surgeons of England, Royal College of Surgeons in 1848 for an essay entitled ''The Origin, Connexions and Distribution of nerves to the human eye and its appendages, illustrated by comparative dissections of the eye in other vertebrate animals.'' In 1852, at the early age of 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
