(N/A) Nephrons are the basic filtering units of kidneys. Each kidney possesses a large number of nephrons,approximately $1-1.5$ million. The main components of the nephron are the glomerulus,Bowman's capsule,and a long renal tubule.
Functioning of a nephron:
$1$. The blood enters the kidney through the renal artery,which branches into many capillaries associated with the glomerulus.
$2$. The water and solutes are transferred to the nephron at Bowman's capsule.
$3$. In the proximal tubule,some substances such as amino acids,glucose,and salts are selectively reabsorbed,and unwanted molecules are added to the urine.
$4$. The filtrate then moves down into the loop of Henle,where more water is absorbed.
$5$. From here,the filtrate moves upwards into the distal tubule and finally to the collecting duct. The collecting duct collects urine from many nephrons.
$6$. The urine formed in each kidney enters a long tube called the ureter. From the ureter,it is transported to the urinary bladder and then into the urethra.