The nephron - Higher tier only
The Bowman’s capsule (renal capsule):
- surrounds a ball of Tiny blood vessels with walls one-cell thick where exchange of materials occurs. called the capillary knot
- high pressure is created in the capillary knot by the diameter of the capillary leaving the knot being narrower than the capillary entering
- this pressure results in The process by which the glomerulus filters water, ions, glucose and other small molecules from the blood. where water, A compound formed by neutralisation of an acid by a base, eg a metal oxide, as the result of hydrogen ions in the acid being replaced by metal ions or other positive ions. Sodium chloride, common salt, is one such compound., A simple sugar used by cells for respiration., and other small molecules pass out of the capillary and into the Bowman's capsule
- proteins and blood cells are too big to leave the capillaries to go into the tubule
The rest of the tubule is responsible for the selective reabsorption of glucose, some salts, and lots of the water.
The collecting duct is responsible for the selective reabsorption of water and for sending urine to the ureter.