GENERAL HISTOLOGY

Detailed explanation-1: -Parathyroid hormone decreases phosphate reabsorption at the proximal convoluted tubule. Phosphate ions in the serum form salts with calcium that are insoluble, resulting in decreased plasma calcium. The reduction of phosphate ions, therefore, results in more ionized calcium in the blood.

Detailed explanation-2: -PTH also causes the release of phosphorus from bone, but because of direct effects in the kidney to increase phosphorus excretion, the net effect of PTH is to lower serum phosphorus levels.

Detailed explanation-3: -Parathyroid hormone regulates calcium levels in the blood, largely by increasing the levels when they are too low. It does this through its actions on the kidneys, bones and intestine: Bones – parathyroid hormone stimulates the release of calcium from large calcium stores in the bones into the bloodstream.

Detailed explanation-4: -This effect is mediated by stimulating tubular reabsorption of calcium. Another effect of parathyroid hormone on the kidney is to stimulate loss of phosphate ions in urine.