Urinary System Embryology Flashcards
What is the allantois?
An outpouching of endoderm at the hindgut that extends into the body stalk
What does the body stalk later form?
Umbilical cord
What is the cloaca?
Common outlet for digestive, urinary and reproduction trac
How does the cloaca develop?
- Cloaca divides to form rectum (GI tract) and anteriorly the urogenital sinus
- Mesonephric duct drains into urogenital sinus
- Urogenital sinus later forms the urinary bladder and its caudal ends forms the urethra
How many sets of kidneys develop during nephrogenesis?
- 3
- Pronephros
- Mesonephros
- Metanephros
What is the pronephros formed from?
Pronephric duct and rudimentary pronephric tubules
What does the pronephros drain into?
Cloaca
When does the pronephros degernate by?
Week 5, except the pronephric duct
What is the mesonephros formed from?
Intermediate mesoderm in trunk region, late week 4
What does the mesonephric duct develop from?
Pronephric
For how long does the mesonephros function as the kidney?
About 4 weeks
What do the mesonephric tubules drain into?
Mesonephric duct
When does the metanephros start to develop and function?
The metanephros starts to develop from about week 5 but starts to function around week 9
What does the metanephros consist of?
- Ureteric bud that develops off the mesonephric duct
- Metanephric mesoderm (most caudal part of the intermediate mesoderm)
What does the ureteric bud develop from?
Mesonephric duct