Embryology Of The Urinary System Flashcards
What layer of the embryo forms the urinary tract?
Intermediate mesoderm.
In which order do the three embryo logical kidney systems develop?
Pronephros,
Mesonephros,
Metanephros.
What is the function of the pronephros?
First kidney system, does not function to filter or excrete, but develops the pronephric duct required for the development of the mesonephric tubules.
Where is the pronephric region?
Extending from the cervical region to the cloaca
What is the function of the mesonephros?
Mesonephric tubules and duct - filter out waste but unable to conserve water. Also plays a role in the development of the male reproductive tract in the form of the vas deferens.
What is the ureteric bud?
Sprouting of intermediate mesoderm from the mesonephric duct that guides the development of the metanephros and definitive kidney.
What type of induction drives the formation of the metanephros and kidney?
Reciprocal induction - ureteric bud releases growth hormones to drive differentiation of caudal intermediate mesoderm, which in turn secretes growth hormones that act upon the ureteric bud.
What is the name given to the mesoderm that forms the nephrons?
What forms the major and minor calyces and ureter?
Metanephric blastema.
Ureteric bud
What is unique about the kidneys in their path during embryological development?
They ascend, undergoing caudal to cranial shift where they pick up innervation of nearby arteries, namely the renal arteries.
What normal anatomical variation may occur in terms of blood supply to the kidney?
Multiple supplemental arterial blood supplies alongside the renal artery.
What is renal agenesis?
Failure of the ureteric bud to interact with intermediate mesoderm. May be unilateral or bilateral.
What results in a pelvic kidney?
What results in a horseshoe kidney?
Failure of ascension (kidney still functions).
Fusion of the poles of the kidney, causing entrapment on the mesenteric artery.
What causes ectopic ureteral orifices?
Where might they occur?
Splitting of the ureteric bud, either partial or complete.
May occur into vagina or urethra, bypassing the bladder.
Where does the bladder develop from?
The cloaca of the hindgut.
What forms the urogenital sinus?
What is the UGS continuous with?
Urorectal septum.
Continuous with the umbilicus - Urachus. This closes to form the median umbilical ligament.
