Urogenital System Development Flashcards
what layer is the kidney derived from?
intermediate mesoderm
where does the kidney development begin? does it migrate? if so, where to?
starts in the pelvis, and ascends to the abdomen
what do both of the kidneys and the gonads arise from?
the urogenital ridge (Intermediate mesoderm)
Specifically, what does the kidney come from?
the nephrogenic cord/nephrotome– its the tissue in the center of the urogenital ridge
what is the pronephros? where is it located? what does it connect to?
transient epithelial cords in the cranial intermediate mesoderm that connect to a pronephric duct which extends towards the cloaca (disappears in humans)
What is the mesonephros derived from?
upper thoracic to upper lumbar intermediate mesoderm
what does the mesonephros consist of?
renal glomeruli and renal tubules which open into the cloaca
what does the ureteric bud arise from?
the mesonephric duct
What is considered the definitive kidney? how is it formed (from what)?
the metanephros; the ureteric bud arises from the mesonephric duct and grows into the sacral intermediate mesoderm (at the metanephric blastema) where it induces the definitive kidney
What happens to the mesonephric tubules/ducts once the metanephros is formed?
they stop producing fluid and end up being involved in the development of the genital system
what is the metanephric blastema? what does it form?
a zone of the sacral intermediate mesoderm that once the ureteric bud grows into it, induces development of renal structures; IT FORMS THE NEPHRONS
what does the ureteric bud become?
the ureter, renal pelvis, calyces, and collecting ducts (tubules) of the kidney
Describe the reciprocal induction of the ureteric bud and metanephric blastema
the ureteric bud induces the metanephric blastema to form from the sacral intermediate mesoderm, and the metanephric blastem induces the ureteric bud to branch (into the ureter, calyces etc.)
Describe the results of branching of the ureteric bud
the first few generations of branching forms the major calyces, the next form minor calyces, and the next form the collecting tubules of the kidney
What does each blastema cap form?
a vesicle that lengthens in a tubular manner; one end forms the bowman’s capsule and surrounds the glomerulus, the rest forms the proximal convoluted, loop of henle, and distal convoluted tubules
what is the function of the kidney (in utero)?
produce and excrete fluid BUT DOES NOT REMOVE WASTE! the waste produces are removed by the placenta! The main function is to PRODUCE AMNIONIC FLUID!!
what can renal agenesis or urethral obstruction lead to?
oligohyrdaminos
Intermediate mesoderm in the sacral region gives rise to ________.
metanephros
the ureteric bud is derived from __________.
mesonephric duct
list the derivatives of the metanephric blastema
nephrons
when do the permanent kidneys begin to function?
9-10 weeks
failure of the kidneys to develop bilaterally results in _________.
oligohydraminos, hypoplastic lungs
what causes the retroperitoneal ascent of the kidneys?
actual migration of the kidney and expansion of the caudal region of the embryo
what supplies the kidneys as they ascend?
common iliac arteries then the lower abdominal aorta and finally the renal arteries
What causes renal agenesis?
faulty inductive interaction between the uteric bud and the metanephric mesoderm
Is unilateral agenesis symptomatic?
NO
What does renal agenesis cause?
do not produce aminonic fluid therefore oligohydraminos
What is congenital polycystic kidney disease? what are the two forms?
= numerous fluid filled-cysts form in the kidneys
- autosomal dominant = slow progression
- recessive form = early renal failure in infancy/childhood
what are common faulty migrations of the kidney?
- Pelvic kidney
2. Horseshoe kidney
What is horseshoe kidney? what arrests kidney ascent?
when the kidneys are fused at their INFERIOR POLES; the inferior mesenteric artery arrests kidney ascent
Do abnormal renal arteries present any clinical symptoms?
NO
What causes duplication of a ureter? where does the second ureter insert?
due to slitting of the ureteric bud; one ureter enters ectopicaly into the vagina, vestibule, or urethra
Due to the migration of the kidneys, other arteries in the pelvis and abdomen supply them before normal renal arteries from the abdominal aorta supply them. This may result in variation of the supply to the kidney if some of these earlier arteries persist. You might then see renal arteries arising from __________.
- common iliacs
2. loweradbominal aorta
How does a horseshoe kidney develop and what crosses over it?
inferior poles fuse as kidneys ascend; inferior mesenteric artery crosses the middle of the fused kidney
what divides the cloaca? what does it divide it into?
divided by the urorectal septum into a dorsal ANORECTAL canal and ventral UROGENITAL sinus
what lines the cloaca?
endoderm
what is the cloacal membrane divided into? do they rupture?
anal and urogenital membranes
what is the bladder and uretha derived from?
the UG sinus (the cloaca gets subdivided into a UG sinus and anorectal anal)
what is the epithelial lining for the bladder and urethra derived from?
the endoderm of the urogenital sinus
what is the muscle/CT of the bladder and urethra derived from?
the mesoderm that surrounds the UG sinus
What are all of the parts of the UG sinus derived from?
endoderm
what are the three parts of the UG Sinus?
- Vesical part
- pelvic part
- phallic part