Final answer:
Microvilli are found on the cells of the PCT in the kidneys, which help increase the surface area for absorption. The filtration process in the kidney involves specialized podocytes in Bowman's capsule, creating a filtrate that passes on to the PCT from the glomerulus. Each kidney has approximately 1.3 million nephrons that filter blood and form urine.
Step-by-step explanation:
In the kidneys, microvilli are found on the brush border of the proximal convoluted tubule (PCT) cells. These microvilli significantly increase the surface area for reabsorption and secretion, crucial for kidney function. Within the renal corpuscle, Bowman's capsule encases a capillary cluster known as the glomerulus, which serves as a high-pressure filtration system. The visceral layer of Bowman's capsule is made up of specialized cells called podocytes. These podocytes have finger-like projections known as pedicels that interdigitate to form a filtration membrane.
Blood in the glomerular capillaries is more filtered than the blood in the peritubular capillaries because it goes through this filtration process where the fenestrations (pores), charge, and basement membrane selectively filter out blood cells and large proteins, creating a filtrate that enters the PCT. This filtration mechanism contributes to the equilibrium of plasma and the excretion of waste via urine. Each kidney contains about 1.3 million nephrons, which are the functional units performing this vital task.