Embryology of the Kidney PDF

07/01/24 Embryology of the Kidney: Learning objective: understand the embryological origin of the urogenital tract. Learning objective: appreciate the stages of development of the kidney, including the pronephros, mesonephros and metanephros. Learning objective: understand the ascent of the kidney....

07/01/24 Embryology of the Kidney: Learning objective: understand the embryological origin of the urogenital tract. Learning objective: appreciate the stages of development of the kidney, including the pronephros, mesonephros and metanephros. Learning objective: understand the ascent of the kidney. The Urogenital system: Develops from the intermediate mesoderm. There are three embryological kidneys which all develop from intermediate mesoderm. Renal development: Pronephros: basic and nonfunctional. Mesonephros: functions during early development. Metanephros: forms the permanent kidney. Pronephros: Appears around the 4th week. Quickly degenerate but leave the pronephric ducts. The pronephric ducts drain caudally ( down ) into the cloaca. The pronephric ducts persist as ducts for the mesonephros. Mesonephros: Appear around 4th week and are caudal ( below ) to pronephros. Approximately 40 glomeruli with mesonephric ducts that open into the pronephric ducts. Function bet ween 6-10 weeks and then degrade. Their tubules become efferent ductules of the testes. Metanephros: This is the development of the permanent kidney. 1. From the mesonephric duct, a ureteric bud develops and meets the intermediate mesoderm to form the metanephrogenic blastema. 2. The bud then bifurcates producing the renal pelvis and collecting tubules. The metanephrogenic blastema differentiates around these tubules to produce the kidney. Nephron development: 1. Ureteric put and metanephric mesenchyme exact reciprocal inductive effects towards each other ( WT1/PAX1 ). 2. 4 stages of nephron development. 3. Mesenchymal cells form a vesicle. 4. Vesicles become S-shaped and connects to ureteric bud. 5. Tubules develop cup-shaped capsule ( bowman’s capsule ). 6. Tubules elongate and glomerulus becomes round and mature. Renal ascent: Basically attaches goes up to aorta Blood via supply the below renal degrades artery and