What are nephrons ? Describe the types of nephrons

Nephrons are the structural and functional units of the kidneys. On the basis of location, the nephrons are of two types :
(a) Juxtamedullary nephron : Their glomeruli are found in the inner margin^ of the cortex. The loop of Henle lie deep into the medulla. They are associated with vasa recta. They control plasma volume when water supply is short.
(b) Cortical nephrons : They mainly lie in the renal
cortex. Their glomeruli are found in the outer cortex. The loops of Henle are short and extend a short distance of medulla. They do not have vasa recta.