9.1 Embryology And The Development Of The Urinary System Flashcards
What is the functional unit of the kidney
Nephron
How does urine drain into the bladder?
Ureter
Where does arterial blood supply to the kidneys stem from?
Abdominal aorta
How many kidney systems form in early embryological life?
3 - pronephros, mesonephros, metanephros
Where do kidney systems develop from?
Intermediate mesoderm
What is the 1st kidney system that develops?
The pronephros
Where does the pronephros develop?
In the cervical region
What is the clinical significance of the pronephros?
Provides useful data on kidney development
What is the function of the pronephros?
Has no clinical function
Forms the duct of the next developmental stage
What is the urogenital ridge?
Region of intermediate mesoderm that gives rise to both the embryonic kidney and gonad
What structures form the embryonic kidney?
Mesonephric tubules
Mesonephric duct
Why does the kidney need to upgrade from the embryonic kidney?
As the embryonic kidney cannot conserve water
What are the important functions of the mesonephros?
• Mesonephric duct has important role in the development of the reproductive system in the male mesonephros
• Mesonephric duct sprouts the ureteric bud which induces
development of the definitive kidney
What is the ureteric bud?
It’s a sprout from the mesonephric duct.
Undifferentiated intermediate mesoderm caudal to the mesonephros
What is the importance of the ureteric bud?
Later forms the ureter
Induces development of undifferentiated mesoderm close by into the true kidney, which can conserve water. Metanephros develops
Why does the maintenance of the mesonephros vary?
Is maintained in males by androgens secreted by developing testis. Degrades in females
What structure is derived from the metanephric blastema?
Kidney
What structure forms the collecting aspects of the kidney?
The ureteric bud of the mesonephric duct
What structures does the ureteric bud form in a developed kidney?
Minor calyx
Major calyx
Renal pelvis
Ureter
What primitive structure forms the excretory part of the kidney?
Metanephric blastema
Where does the metanephric kidney first appear?
In the pelvic region, near the cloaca
Describe the movement of the kidneys during development
Caudal to cranial shift (ascent)
Crosses the arterial fork formed by vessels returning blood from the foetus into the placenta