Dialysis blocks the passage of larger substances (for example, red blood cells, large proteins). This replicates the filtering process that takes place in the kidneys when the blood enters the kidneys and the larger substances are separated from the smaller ones in the glomerulus. The two main types of dialysis, hemodialysis and peritoneal dialysis, remove wastes and excess water from the blood in different ways. Hemodialysis removes wastes and water by circulating blood outside the body through an external filter, called a dialyzer, that contains a semipermeable membrane. The blood flows in one direction and the dialysate flows in the opposite.
The Foolish Old Man Removes the Mountains The Foolish Old Man Removes the Mountains The Foolish Old Man Removes the Mountains () is a well-known fable from Chinese mythology about the virtues of perseverance and willpower. The tale first appeared in Book 5 of the "Liezi", a Daoist text of the 4th century BC, and was retold in the "Garden of Stories" by the Confucian scholar Liu Xiang in the 1st century BC. It was also used by Mao Zedong in a famous speech in 1945. The myth concerns a Foolish Old Man of 90 years who lived near a pair of mountains (given in some tellings