Kidney a minor calyx; minor calyces empty into major calyces, and major calyces empty into the renal pelvis. This becomes the ureter. At the hilum, the ureter and renal vein exit the kidney and the renal artery enters. Hilar fat and lymphatic tissue with lymph nodes surrounds these structures. The hilar fat is contiguous with a fat-filled cavity called the renal sinus. The renal sinus collectively contains the renal pelvis and calyces and separates these structures from the renal medullary tissue. The kidneys possess no overtly moving structures. The renal circulation supplies the blood to the kidneys via the renal arteries,
Left anterior descending artery the right aortic sinus. In 78% of cases, it reaches the apex of the heart. The LAD gives off two types of branches: "septals" and "diagonals". The artery supplies the anterolateral myocardium, apex, and interventricular septum. The LAD typically supplies 45-55% of the left ventricle (LV) and is therefore considered the most critical vessel in terms of myocardial blood supply. The "widow maker" is an alternate name for the anterior interventricular branch of the left coronary artery. The name "widow maker" may also apply to the left coronary artery or severe occlusions to that artery. This term is used because