Kidneys with a complete parenchymal bridge in the sinus, which is diagnostic for a duplex collecting system, were also excluded from the study. The children were between 1 month and 18 years old (mean age, 6.1 Â± 5.9 years).he objective of our study was to develop, by use of ultrasound, nomograms of renal parenchymal thickness, medullary pyramid thickness (height), renal length, and the ratio of medullary pyramid thickness to parenchymal thickness in healthy children.
erythropoietin. a glycoprotein hormone secreted by the kidney in the adult and by the liver in the fetus, which acts on stem cells of the bone marrow to stimulate red blood cell production (erythropoiesis).
Renin is produced by the kidneys and controls the activation of the hormone angiotensin, which stimulates the adrenal glands to produce aldosterone. The kidneys release renin when there is a drop in blood pressure or a decrease in sodium chloride concentration in the tubules in the kidney.