Veins are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart. In the systemic circulation, arteries carry oxygenated blood away from the heart, and veins return deoxygenated blood to the heart, in the deep veins.
The left and right brachiocephalic veins are major veins in the upper chest, formed by the union of the ipsilateral internal jugular vein and subclavian vein behind the sternoclavicular joint. The left brachiocephalic vein is more than twice the length of the right brachiocephalic vein.
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.
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 vertebra.
The azygos vein 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.
In human anatomy, the abdominal aorta is the largest artery in the abdominal cavity. As part of the aorta, it is a direct continuation of the descending aorta.
The renal arteries are paired arteries that supply the kidneys with blood. Each is directed across the crus of the diaphragm, so as to form nearly a right angle.
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.
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.
In human anatomy, the hepatic veins are the veins that drain venous blood from the liver into the inferior vena cava. There are usually three large upper hepatic veins draining from the left, middle, and right parts of the liver, as well as a number (6-20) of lower hepatic veins. All hepatic veins are valveless.
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.
The inferior phrenic artery is a bilaterally paired artery of the abdominal cavity which represents the main source of arterial supply to the diaphragm. Each artery usually arises either from the coeliac trunk or the abdominal aorta, however, their origin is highly variable and the different sites of origin are different for the left artery and right artery. The superior suprarenal artery is a branch of the inferior phrenic artery.
The middle suprarenal artery is a paired artery in the abdomen. It is a branch of the aorta. It supplies the adrenal gland.
The testicular artery is a branch of the abdominal aorta that supplies blood to the testicle. It is a paired artery, with one for each of the testicles.
The ovarian vein, the female gonadal vein, carries deoxygenated blood from its corresponding ovary to inferior vena cava or one of its tributaries. It is the female equivalent of the testicular vein, and is the venous counterpart of the ovarian artery. It can be found in the suspensory ligament of the ovary.
The testicular vein, the male gonadal vein, carries deoxygenated blood from its corresponding testis to the inferior vena cava or one of its tributaries. It is the male equivalent of the ovarian vein, and is the venous counterpart of the testicular artery.
The lumbar veins are four pairs of veins running along the inside of the posterior abdominal wall, and drain venous blood from parts of the abdominal wall. Each lumbar vein accompanies a single lumbar artery. The lower two pairs of lumbar veins all drain directly into the inferior vena cava, whereas the fate of the upper two pairs is more variable.
The pampiniform plexus is a venous plexus – a network of many small veins found in the human male spermatic cord, and the suspensory ligament of the ovary. In the male, it is formed by the union of multiple testicular veins from the back of the testis and tributaries from the epididymis.
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.
In anatomy, the venae cavae are two large veins that return deoxygenated blood from the body into the heart. In humans they are the superior vena cava and the inferior vena cava, and both empty into the right atrium. They are located slightly off-center, toward the right side of the body.
