Veins are blood vessels that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. In contrast to veins, arteries carry blood away from the heart.
The circulatory system, also called the cardiovascular system or the vascular system, is an organ system that permits blood to circulate and transport nutrients, oxygen, carbon dioxide, hormones, and blood cells to and from the cells in the body to provide nourishment and help in fighting diseases, stabilize temperature and pH, and maintain homeostasis.
The great saphenous vein is a large, subcutaneous, superficial vein of the leg. It is the longest vein in the body, running along the length of the lower limb, returning blood from the foot, leg and thigh to the deep femoral vein at the femoral triangle.
The pulmonary veins are the veins that transfer oxygenated blood from the lungs to the heart. The largest pulmonary veins are the four main pulmonary veins, two from each lung that drain into the left atrium of the heart. The pulmonary veins are part of the pulmonary circulation.
The great cerebral vein is one of the large blood vessels in the skull draining the cerebrum of the brain. It is also known as the "vein of Galen", named for its discoverer, the Greek physician Galen. However, it is not the only vein with this eponym.
The small saphenous vein, is a relatively large superficial vein of the posterior leg.
The dorsal venous arch of the foot is a superficial vein that connects the small saphenous vein and the great saphenous vein. Anatomically, it is defined by where the dorsal veins of the first and fifth digit, respectively, meet the great saphenous vein and small saphenous vein.
The anterior tibial vein is a vein in the lower leg.
The arachnoid mater is one of the three meninges, the protective membranes that cover the brain and spinal cord. The arachnoid mater is a derivative of the neural crest mesectoderm in the embryo.
The vitelline veins are veins that drain blood from the yolk sac and the gut tube during gestation.
The dorsal venous network of the hand is a network of veins within the superficial fascia on the dorsum (backside) of hand. It is formed by the dorsal metacarpal veins, and gives rise to veins such as the cephalic vein and the basilic vein.
On the dorsum of the foot the dorsal digital veins receive, in the clefts between the toes, the intercapitular veins from the plantar venous arch and join to form short common digital veins which unite across the distal ends of the metatarsal bones in a dorsal venous arch.
The external vertebral venous plexuses best marked in the cervical region, consist of anterior and posterior plexuses which anastomose freely with each other.
Venous leak, also called venogenic erectile dysfunction and penile venous insufficiency, is one category of vasculogenic impotence -a cause of erectile dysfunction in males. It affects all ages, being particularly awkward in young men. Much about venous leaks has not reached a consensus among the medical community, and many aspects of the condition, particularly its treatment strategies, are controversial. The prevalence of the condition is still unknown, although some sources claim it to be a common cause of erectile dysfunction.
On the dorsum of the foot the dorsal digital veins receive, in the clefts between the toes, the intercapitular veins from the plantar venous arch and join to form short common digital veins.
The pudendal venous plexus lies behind the arcuate pubic ligament and the lower part of the pubic symphysis, and in front of the bladder and prostate. Its chief tributary is the deep dorsal vein of the penis, but it also receives branches from the front of the bladder and prostate. It communicates with the vesical venous plexus and with the internal pudendal vein and drains into the vesical and hypogastric veins.
The palmar digital veins on each finger are connected to the dorsal digital veins by oblique intercapitular veins. They drain into a venous plexus which is situated over the thenar and hypothenar eminences and across the front of the wrist.
Anterior spinal veins are veins that receive blood from the anterior spinal cord.
Chronic venous insufficiency (CVI) is a medical condition in which blood pools in the veins, straining the walls of the vein. The most common cause of CVI is superficial venous reflux which is a treatable condition. As functional venous valves are required to provide for efficient blood return from the lower extremities, this condition typically affects the legs. If the impaired vein function causes significant symptoms, such as swelling and ulcer formation, it is referred to as chronic venous disease. It is sometimes called chronic peripheral venous insufficiency and should not be confused with post-thrombotic syndrome in which the deep veins have been damaged by previous deep vein thrombosis.
Heart development refers to the prenatal development of the heart. This begins with the formation of two endocardial tubes which merge to form the tubular heart, also called the primitive heart tube. The heart is the first functional organ in vertebrate embryos, and in the human, beats spontaneously around week 5 of development.
