Development of the Urinary System Flashcards
What are the kidneys derived from?
Intermediate mesoderm
What is the earliest nephric stage?
Pronephros
What appears after the pronephros?
Mesonephros
What drives the development of the mesonephros?
Pronephric duct
Where does the pronephric duct extend from and to?
Cervical region to the cloaca
What is the urogenital ridge?
Region of intermediate mesoderm giving rise to both the embryonic kidney and the gonad
True or False:
The mesonephros can both produce urine and conserve water
False
Cannot conserve water
What is the importance of the mesonephric duct?
Developent of the male reproductive system
What does the mesonephric duct have that induces development of the definitive kidney?
Ureteric bud
What is the importance of the ureteric bud?
Induces development of the true kidney - metanephros
What does the ureteric bud later form?
Ureter
Why do the kidneys need to ascend?
Metanephric kidney first appears in the pelvic region so has to undergo a cadal to cranial shift
When does the metanephros arise?
5th week of gestation
What are accessory renal arteries?
Embryological arteries that fail to regress as the kidney ascends
What happens if the ureteric bud fails to interact with the intermediate mesoderm?
Renal agenesis
What is a pelvic kidney?
When a kidney fails to ascend and remains in the pelvis
What is horseshoe kidney?
Where two developing kidneys fuse into a single horshoe-shaped structure
How can horseshoe kidney occur?
If kidneys become too close together during their ascent and become fused underneath the inferior mesenteric artery
What is an ectopic ureter?
Ureter that does not connect with the bladder (eg drains into urethra or vagina instead)
What is the dilated structure that the hindgut ends in called?
Cloaca
What is the urogenital sinus?
Created from hindgut by urorectal septum
Ventral part of cloaca after it is split
What does the urachus go on to form?
Median umbilical ligament
What does the superior part of the urogenital sinus connect to?
Umbilicus
What does the majority of the urogenital sinus differentiate to form?
urinary bladder
What does the inferior part of the urogenital sinus devleop into?
Urethra
What 4 parts is the male urethra divided into?
1) Pre-prostatic
2) Prostatic
3) Membranous
4) Spongy
In males, what is the pre-prostatic urethra?
Part that leaves bladder before entering body of prostate
In males, what is the prostatic urethra?
Part of urethra that runs through prostate
In males, what is the membranous urethra?
Part of urethra that passes through peritoneum
In males, what is the spongy urethra?
Part of urethra that runs along the shaft of the penis
What is hypospadias?
Defect in fusion of urethral folds so the urethra opens onto the ventral surface rather than at the end of the glans
