Bilateral renal agenesis is typically diagnosed using prenatal ultrasound. Normally the fetal kidneys can be visualized starting at approximately the twelfth week of gestation. In bilateral renal agenesis, however, no…
Most malrotated kidneys do not require definitive treatment. If significant symptoms persist, however, or if significant hydronephrosis is present, surgical repair of the renal pelvis and/or ureteropelvic junction may be…
Most patients with pelvic kidneys are asymptomatic, and the abnormality is either incidentally noted or never discovered. A subset of individuals, however, may become symptomatic secondary to the development of…
The crossed kidney generally lies caudal to the normally positioned kidney and has a ventrally oriented renal pelvis. In 90% of cases, the crossed kidney is fused with the inferior…
MATURATION OF THE BLADDER After cloacal septation is complete, the primitive urogenital sinus contains three major parts. The most caudal part is known as the definitive urogenital sinus, and it…
FATE OF THE MESONEPHRIC DUCTS By the end of the exstrophy process, the mesonephric ducts terminate in the bladder medial and inferior to the future ureteric orifices. Although it was…
The metanephroi begin to produce urine at 9 weeks of gestation, even as active nephrogenesis is ongoing. Such urination becomes essential for maintaining a normal volume of amniotic fluid. The…
METANEPHROS The paired metanephroi are the precursors of the definitive adult kidneys. They begin to form around the twenty-eighth day of gestation, shortly after the mesonephric ducts have fused with…
OUTER AND INNER MEDULLARY COLLECTING DUCT The outer medullary collecting duct (OMCD) consists of principal cells and a smaller population of type A intercalated cells. Both appear taller and less…
Unlike in the ureter, the lamina propria occasionally contains a muscularis mucosae, which appears discontinuous and contains a haphazard arrangement of wispy, thin bundles of smooth muscle cells. In some…
