how does a nephron work?

A nephrons functions are to filter the blood and takes out unwanted chemicals. The capsule filters out water, sugar, salts, and urea then transports them to the tubule. Water is absorbed by the tubule in the blood while whatever is left over turns into urine. The proximal and distal helps absorb certain things that the body requires like calcium, protein, etc....

a nephron is the basic functional and histological unit of the kidney, its composed of a renal corpuscle (bowmans capsule and glomerulus) proximal convuluted tubule, loop of henle, distal convoluted tubule. (in that order)
the DCT emptied into a collecting duct which carries urine from the cortex of the kidney toward the renal papilla.
the glomerulus is very permeable, it looks like a ball of yarn, and solutes are filtered across its wall into the bowmans capsule, which in turn drains to the PCT.
the bowmans walls are made of simple squamous tissue, very permable. It has window like openings called fenestrae, and also filtration slits.
at the PCT Na and others are removed by active transport, water passively filters. Filtrate volume is reduced.
at the DCT water exits, solutes enter
at the ascening LOH Na, Cl and K are then transported out of the filtrate but water remains as its walls are impermeable to water.




http://en.wikipedia.org/wiki/Nephron
http://science.howstuffworks.com/environmental/life/human-biology/kidney1.htm