And what these tide junctions do is they basically prevent the movement of these waste products from the lumen of our Proximal Convoluted tubular from the filtrate back into our blood plasma of these peritubular capillaries. Now, all the surrounding tissues found around the Proximal Convoluted tubule is known as our interstituum. So what the Proximal Convolutes do is they prevent the movement of these waste products from the filtrate back into our interstituum. Now, these epithelial cells basically contain foldings on the membrane, and these foldings are known as the microvilli. And the microvilli greatly increases the surface area of the inner lining of our Proximal Convoluted tubule, and this increases the rate of reabsorption as well as secretion along the entire Proximal Convoluted tubule. Now, the epithelial cell membranes also contain special type of integral proteins found within our membrane.