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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 of about fourteen days, with yolk sac The yolk sac is a membranous wikt:sac, sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though ''yolk sac' .... References External links * Diagram at nature.com Embryology of cardiovascular system {{circulatory-stub ... [...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. Fertilization occurs when the sperm cell successfully enters and 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. Embryonic development in the human, covers the first eight weeks of development; at the beginning of the ninth week the embryo is termed a fetus. Human embryology is the study of this development during the first eight weeks after fertilization. The normal period of gestation (pregnancy) is about nine months or 40 weeks. The germinal stage refers to the time from fertilization ... [...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, 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 devel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiovascular System
The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek ''kardia'' meaning ''heart'', and from Latin ''vascula'' 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 the ''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. Some invertebrates such as ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Jugular Veins
The internal jugular vein is a paired jugular vein that collects blood from the brain and the superficial parts of the face and neck. This vein runs in the carotid sheath with the common carotid artery and vagus nerve. It begins in the posterior compartment of the jugular foramen, at the base of the skull. It is somewhat dilated at its origin, which is called the ''superior bulb''. This vein also has a common trunk into which drains the anterior branch of the retromandibular vein, the facial vein, and the lingual vein. It runs down the side of the neck in a vertical direction, being at one end lateral to the internal carotid artery, and then lateral to the common carotid artery, and at the root of the neck, it unites with the subclavian vein to form the brachiocephalic vein (innominate vein); a little above its termination is a second dilation, the ''inferior bulb''. Above, it lies upon the rectus capitis lateralis, behind the internal carotid artery and the nerves passing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Vena Cava
The superior vena cava (SVC) is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. It is a large-diameter (24 mm) short length vein that receives venous return from the upper half of the body, above the diaphragm. Venous return from the lower half, below the diaphragm, flows through the inferior vena cava. The SVC is located in the anterior right superior mediastinum. It is the typical site of central venous access via a central venous catheter or a peripherally inserted central catheter. Mentions of "the cava" without further specification usually refer to the SVC. Structure The superior vena cava is formed by the left and right brachiocephalic veins, which receive blood from the upper limbs, head and neck, behind the lower border of the first right costal cartilage. It passes vertically downwards behind first intercostal space and receives azygos vein just before it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Jugular Vein
The internal jugular vein is a paired jugular vein that collects blood from the brain and the superficial parts of the face and neck. This vein runs in the carotid sheath with the common carotid artery and vagus nerve. It begins in the posterior compartment of the jugular foramen, at the base of the skull. It is somewhat dilated at its origin, which is called the ''superior bulb''. This vein also has a common trunk into which drains the anterior branch of the retromandibular vein, the facial vein, and the lingual vein. It runs down the side of the neck in a vertical direction, being at one end lateral to the internal carotid artery, and then lateral to the common carotid artery, and at the root of the neck, it unites with the subclavian vein to form the brachiocephalic vein (innominate vein); a little above its termination is a second dilation, the ''inferior bulb''. Above, it lies upon the rectus capitis lateralis, behind the internal carotid artery and the nerves pas ... [...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 prenatal development. These drain an and a |
Superior Vena Cava
The superior vena cava (SVC) is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. It is a large-diameter (24 mm) short length vein that receives venous return from the upper half of the body, above the diaphragm. Venous return from the lower half, below the diaphragm, flows through the inferior vena cava. The SVC is located in the anterior right superior mediastinum. It is the typical site of central venous access via a central venous catheter or a peripherally inserted central catheter. Mentions of "the cava" without further specification usually refer to the SVC. Structure The superior vena cava is formed by the left and right brachiocephalic veins, which receive blood from the upper limbs, head and neck, behind the lower border of the first right costal cartilage. It passes vertically downwards behind first intercostal space and receives azygos vein just before it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circulatory Anastomosis
A circulatory anastomosis is a connection (an anastomosis) between two blood vessels, such as between arteries (arterio-arterial anastomosis), between veins (veno-venous anastomosis) or between an artery and a vein (arterio-venous anastomosis). Anastomoses between arteries and between veins result in a multitude of arteries and veins, respectively, serving the same volume of tissue. Such anastomoses occur normally in the body in the circulatory system, serving as backup routes for blood to flow if one link is blocked or otherwise compromised, but may also occur pathologically. Physiologic Arterio-arterial anastomoses include actual (e.g., palmar and plantar arches) and potential varieties (e.g., coronary arteries and cortical branch of cerebral arteries). There are many examples of normal arterio-arterial anastomoses in the body. Clinically important examples include: * Circle of Willis (in the brain) *Coronary: anterior interventricular artery and posterior interventricular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachiocephalic Vein
The left and right brachiocephalic veins (previously called innominate veins) are major veins in the upper chest, formed by the union of each corresponding internal jugular vein and subclavian vein. This is at the level of the sternoclavicular joint. The left brachiocephalic vein is nearly always longer than the right. These veins merge to form the superior vena cava, a great vessel, posterior to the junction of the first costal cartilage with the manubrium of the sternum. The brachiocephalic veins are the major veins returning blood to the superior vena cava. Tributaries The brachiocephalic vein is formed by the confluence of the subclavian and internal jugular veins. In addition it receives drainage from: * Left and right internal thoracic vein (Also called internal mammary veins): drain into the inferior border of their corresponding vein * Left and right inferior thyroid veins: drain into the superior aspect of their corresponding veins near the confluence * Left and rig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yolk Sac
The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though ''yolk sac'' is far more widely used. In humans, the yolk sac is important in early embryonic blood supply, and much of it is incorporated into the primordial gut during the fourth week of embryonic development. In humans The yolk sac is the first element seen within the gestational sac during pregnancy, usually at 3 days gestation. The yolk sac is situated on the front (ventral) part of the embryo; it is lined by extra-embryonic endoderm, outside of which is a layer of extra-embryonic mesenchyme, derived from the epiblast. Blood is conveyed to the wall of the yolk sac by the primitive aorta and after circulating through a wide-meshed capillary plexus, is returned by the vitelline veins to the tubular heart of the embryo. This constitutes the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
