Blood vessel also increased in inflammation in response to histamine, prostaglandins and interleukins, which leads to most of the symptoms of inflammation (swelling, redness, warmth and pain). Arteries—and veins to a degree—can regulate their inner diameter by contraction of the muscular layer. This changes the blood flow to downstream organs, and is determined by the autonomic nervous system. Vasodilation and vasoconstriction are also used antagonistically as methods of thermoregulation. The size of blood vessels is different for each of them. It ranges from a diameter of about 25 millimeters for the aorta to only 8 micrometers in the capillaries. This comes out
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