Urinary System Development Flashcards
(27 cards)
What germ layer gives rise to the urogenital ridge?
intermediate mesoderm
How many kidneys develop from each nephrogenic cord?
3
what are the names of the 3 early kidneys?
pronephros, mesonephros, and metanephros
What becomes the functional kidney in adult mammals?
metanephros
What do the tubules of the mesonephros and pronephros drain into?
the pronephric and mesonephric duct
describe the similar development of pronephros and mesonephros
nephrogenic cord segments into tubules that drain into duct, tubules eventually disintegrate
What do mesonephric tubules surround?
glomeruli - vascular proliferation produced by branch of dorsal aorta
What does the mesonephric duct persist as in the adult?
the epididymis and ductus deferens
Where does the metanephros originate in the body and where does it move to?
originates in pelvic region and moves cranially into abdomen
What are the 2 sources the metanephros originates from?
ureteric bud and metanephrogenic mass
What does the ureteric bud develop into?
ureter, renal pelvis, and collecting ducts
What does the metanephrogenic mass develop into?
nephrons
What forms cell cords in early nephron formation?
mesodermal cells of the metanephrogenic mass
what do cell cords in the metanephrogenic mass become?
metanephric tubules and eventually nephrons
what happens at the ends of a metanephric tubule in nephron formation?
one end surrounds a capillary glomerulus to become a glomerular capsule and the other end connects to a collecting duct
What are the 3 characteristic regions of a nephron?
proximal segment, thin loop, distal segment
metanephric tubule differentiates into these
What divides the cloaca?
the urorectal septum
what does the dorsal cloaca become?
rectum, anal canal, and anal membrane (anus)
what does the ventral cloaca become?
urogenital sinus and urogenital membrane (urogenital orifice)
what is the urachus and where does it attach?
it’s the intraembryonic stalk of the allantois and it attaches to the cranial urogenital sinus
what creates the trigone region?
the mesonephric duct and ureter openings switch places. The ureters move cranially and leave behind longitudinal muscles.
What becomes the urethra?
the caudal urogenital sinus
cranial is bladder
Describe female urethra development
mid urogenital sinus becomes urethra
caudal urogenital sinus becomes vestibule
Describe male urethra development
mid urogenital sinus becomes pelvic urethra
caudal urogenital sinus becomes elongated penile urethra
