Cerebrovascular disease capillary bed separates arteries from veins, which protects the veins from the higher blood pressures that occur in arteries. In arteriovenous malformations, arteries are directly connected to veins, which increases the risk of venous rupture and hemorrhage. Arteriovenous malformations in the brain have a 2–4% chance of rupture each year. However, many arteriovenous malformations go unnoticed and are asymptomatic throughout a person's lifetime. A germinal matrix hemorrhage is bleeding into the brain of premature infants caused by the rupture of fragile blood vessels within the germinal matrix of premature babies. The germinal matrix is a highly vascularized area within an
Patellar network Patellar network The patellar network (circulatory anastomosis around the knee-joint, patellar anastomosis, genicular anastomosis, articular vascular network of knee or rete articulare genus) is an intricate network of vessels around and above the patella, and on the contiguous ends of the femur and tibia, forming a superficial and a deep plexus. The arteries which form this plexus are the inferior medial and superior medial genicular arteries, the inferior lateral and superior lateral genicular arteries, the descending genicular artery, the descending branch of lateral femoral circumflex artery, and the anterior tibial recurrent artery. The genicular anastomosis provides collateral circulation to supply