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).
Hormonal regulation of hormone release involves a hormone binding to its receptor on an endocrine cell to regulate hormonal secretion. A hormone that stimulates hormone secretion is called a tropic hormone. Tropic hormones may also stimulate proliferation of endocrine cells.Recall that endocrine secretion is whatever occurs to increase the amount of hormone in the circulation). An example is the hormone adrenocorticotropic hormone (ACTH) that stimulates secretion of the steroid hormone cortisol by cells of the zona fasciculata in the adrenal cortex.