Calcium is one substance that is secreted elsewhere but not in the proximal convoluted tubule.
<h3>Renal reabsorption and secretion</h3>
Renal reabsorption is defined as the movement of water and specific solutes from the renal tubule back into the plasma.
Renal secretion is defined as the process by which waste ions and hydrogen ions pass from the renal capillaries into the renal tubule to be excreted into the urine.
At the proximal convoluted tubule, calcium is reabsorbed but not secreted. Therefore, Calcium is one substance that is secreted elsewhere but not in the proximal convoluted tubule.
The answer to the first question is (C). The lithosphere includes the crust and the cooler upper part of the upper mantle. It averages about 50 miles in thickness, give or take ten miles. The answer to the second question is (D), the innder core is solid because of immense pressure.
