1 Strenuous exercise, such as running a marathon, can also cause blood in the urine. 2  White blood cells may be a sign of infection or kidney disease. 3  Casts. 4  Some types of kidney disease can cause plugs of material (called casts) to form in tiny tubes in the kidneys.
Top 10 facts about the world. The loop of Henle is a part of a nephron, a tiny tube inside the kidneys that filters solutes. Each kidney contains hundreds of thousands of individual nephrons, which pass between the cortex of the kidneys and the medulla, connecting to collecting ducts which route urine to the ureter so that it can be expressed.
loops of Henle and collecting ducts, vascular vessels run through the adjacent tissue called the renal columns, collecting ducts feed into a branch of renal pelvis called a calyx.