Developmet Of the Urinary System Flashcards
What does the intermediate mesenchyme give rise to?
Urogenital ridge
What components make up the urogenital ridge?
Nephrogenic cord
Gonadal ridge
What structures make up the nephrogenic cord?
Pronephroi
Mesonephroi
Metanephroi
What structure does the pronephroi give rise to?
Rudimentary, non-functional kidneys
When do the rudimentary, non-functional kidneys appear? When do they regress?
Around the third week of gestation and regress by the fifth week
What structure does the mesonephroi give rise to?
Interim kidneys for the first trimester
Mesonephric duct (Wolffian duct)
What induces the development of the mesonephroi?
Pronephric duct
What structure does the metanephroi give rise to?
Permanent kidneys
How does the metanephros develop?
From the mesonephric outgrowth called ureteric bud
When does the metanephros develop?
During week 5
When is the metanephros fully canalised and functioning?
By week 10
What are the derivatives of the metanephros?
Ureteric bud
Metanephric mesenchyme
What does the ureteric bud develop into? (3)
- Ureter
- Pelvises
- Calyces and collecting ducts
What causes the metanephric mesenchyme to differentiate? And to what?
Interaction with ureteric bud causes metanephric mesenchyme to differential the renal structures from collecting tubules to glomerulus
What are the components of the interim kidneys?
Glomeruli and mesonephric tubules
What structures does the metanephric blastema give rise to? (4)
- DCT
- Loop of Henle
- PCT
- Renal corpuscle
What is the relation between collecting tubules and metanephric blastema?
Metanephric blastema surrounds newly formed collecting tubules –> mesenchymal cells transform themselves and form metanephric vesicles
When is the kidney lobulated?
During the fetal stage, lobulation disappears in infancy
What does it mean if lobulation persists in adulthood, too?
Caused by incomplete fusion of the developing renal lobules
What is the location of the metanephric kidneys?
They lie close to each other in the pelvis
What is the rotation of the kidneys like?
- The caudal part of the embryo grows away from the kidneys so that the kidneys occupy progressively higher cranial levels
- As the kidneys change their position and “ascend”, they rotate medially almost 90o
- By the 9th week, the kidneys come in contact with the suprarenal glands as they attain their adult position
Initially, the renal arteries are branches of what?
The common iliac arteries
Later on, where do the kidneys start receiving blood from?
The distal end of the aorta
Where do the kidneys receive their most cranial arterial branches from?
The abdominal aorta eventually becomes the renal arteries