Steps of Urine Formation

Step 1 (glomerular filtration)

Creates a plasmalike filtrate of the blood.

Step 2 (tubular reabsorption)

Removes useful solutes from the filtrate, returns them to the blood.

Step 3 (tubular secretion)

Removes additional wastes from the blood, adds them to the filtrate.

Step 4 (water conservation)

Removes water from the urine and returns it to blood, concentrates wastes.