Tiêu đề Part 2 Urine Formation.pdf ✅

Urine formation involves three main processes ⓵ Glomerular filtration ⓶ Reabsorption ⓷ Tubular Secretion
⓵ GLOMERULAR FILTRATION ➢ The first step in urine formation is the filtration of blood, which is carried out by the glomerulus ➢ This process occurs in the Malpighian corpuscle of the nephron ➢ The filtration membrane consist of 3 layers: 1. Endothelium of glomerular blood vessels. 2. Epithelium of Bowman’s capsule. 3. Basement membrane between these two layers. ➢ Epithelial cells (podocytes) of the Bowman’s capsule are arranged in an intricate manner leaving some minute spaces called filtration slits (slit pores). ➢ Almost all constituents of blood plasma except the proteins pass onto lumen of Bowman’s capsule. Therefore, it is considered as a process of ultra filtration
⓵ GLOMERULAR FILTRATION ➢ The plasma fluid filters out from glomerular capillaries into bowman's capsule of nephrons is called glomerular filtrate ➢ About 1100-1200 ml of blood is filtered by kidneys per minute. It constitutes 1/5th of the blood pumped out by each ventricle of the heart in a minute. ➢ The amount of glomerular filtrate formed per minute is called Glomerular filtration rate (GFR). ➢ Normal GFR = 125 ml/minute, i.e., 180 litres/day.