21. Any sympathetic stimulation to the venous system will increase venous return to the heart and ventricular filling. 22. Perforator veins play a very special role in the venous system , carrying blood from superficial to deep veins. 23. Both capillary beds and the blood vessels that connect them are considered part of the portal venous system . 24. Following the ballooning, there is the process of pinching, which separates the "'lymph sacs "'from the venous system . 25. This spares the portal venous system from high pressure which can cause esophageal varices, caput medusae, and hemorrhoids. 26. The disease presumably begins with a deep vein thrombosis that progresses to total occlusion of the deep venous system . 27. In this case they are called perforator veins and have a very important role in the venous system hemodynamics. 28. It has neurons which generate and release pulses of GnRH into the portal venous system of the pituitary gland. 29. When thrombophlebitis affects the greater veins, it can progress into the deep venous system , and may lead to pulmonary embolism. 30. Beginning in 1937 Batson began a series of injection experiments investigating the anatomy and physiology of the cerebrospinal venous system .
