Development Of The Liver & Kidney

1. Development

-hepatic diverticulum (endoderm of foregut) forms in septum transversum (surrounding mesoderm, also plays part in development of diaphragm)

-HD sends hepatic cell cords into ST

-Cell cords surround vitelline veins, which form hepatic sinusoids

1. Development

-Intermediate mesoderm forms elevation along dorsal body wall = urogenital ridge

-portion of UG ridge, called nephrogenic cord, forms 3 sets of kidneys

1. Pronephros completely regresses

2. Mesonephros forms mesonephric (wolffian) duct

3. Metanephros develops from metanephric mesoderm and ureteric bud (outgrowth of mesonephric duct); becomes definitive adult kidney

-ascends during development from sacral region to adult location at T12-L3

2. Congenital anomalies

1. Renal agenesis - failure of ureteric bud to develop

2. Horseshoe kidney – inferior poles fuse, kidney trapped behind inf. mesenteric artery

3. Wilm’s tumor – malignant tumor in children, probably of embryonic origin, good prog

4. Urachal cyst – remnant of allantois, urine drainage from umbilicus

5. Pheochromocytoma – chromaffin cell tumor, generally along migratory path of neural crest cells

Category: Anatomy Notes