Notes

PROCESS OF ULTRAFILTRATION:
the activity of the nephron is based on three principles: ultrafiltration, selective reabsorption and secretion. in ultrafiltration part of the fluid is pushed into the glomerulus and is filtered. in reabsorption, materials that are required for the body such as glucose and water are reabsorbed. in the secretion, ammonia and other harmful substances are excreted. renal artery supplies blood to the kidney. it later branches into smaller blood vessels afferent vessels, which carries blood to the glomerulus. from here the efferent vessels carry blood to the nephrons which later joins with the renal vein. the diameter of the afferent vessel is larger than the efferent vessel which means that the blood is filtered under pressure. this means that some of the liquid and dissolved particles are pushed out of the glomerulus into the Bowman's capsule. here the cells and larger particles cannot enter. the filtrate needs to pass through three barriers: wall of the glomerulus, basement membrane and the inner wall of the Bowman's capsule. the walls of the glomerulus have small pores and it allows the blood vessels to pass through. the basement membrane does not allow cells and blood vessels to pass through. the inner wall of the Bowman's capsule also stops the blood vessels from entering.

EXPLAIN REABSORPTION: