Renal Embryology

kschmidt's version from 2015-12-18 07:16


Question Answer
common developmental origin - anatomically and embryologicallyurinary and genital systems; their ductal systems (from mesodermal ridge on posterior abdominal wall)
most of the urinary system develops fromintermediate mesoderm and urogenital sinus
intermediate mesoderm is locatedbetween paraaxial and lateral mesoderm; extends along dorsal body wall of embryo
urogenital sinus is the ? part of the cloacaendodermal
kidney and ureter develop from intermediate mesoderm
urinary bladder and urethra develop fromurogenital sinus
urorectal septum divides the hindgut intourogenital sinus (ventral) and anal canal (cranial part)/rectum (dorsal)
the cloaca is an endodermal cavity, constituting the expanded lower part of the hindgut
the cloaca receives theallantois and its yolk sac diverticulum
ectodermal component of cloacal membrane isproctodeum
the urorectal septum is ? tissuemesenchymal tissue
the urorectal septum fuses withcloacal membrane
cloacal membrane is divided intourogential membrane and anal membrane
ectodermal depression proctodeum appears at theanal membrane
Pronephrons appear when and where?early in week 4 in cervical region; transitory/nonfunctional; degenerate except pronephric duct
proliferation of the cells of the intermediate mesdoderm proliferate and formnephrogenic cords
mesonephros develop where and when?late in week 4; thoracolumbar region
mesonephros are functional for how long?about 4 weeks
mesonephros consist of mesonephric tubules and open into mesonephric (used to be pronephric) ducts
mesonephric ducts eventually formductus deferens and duct of epididimy
metanephros (primodrium of permanent kidneys) develop where and when? functional when?sacral region, early week 5; week 9 (urine formation begins)
metaphrenic diverticulum or uteric bud form fromthe caudal end of the MESOphrenic duct
metanephric mass of intermediate mesoderm captsthe uteric bud and forms the permanent kidney
the uteric bud/metanephric diverticulum gives rise toureters, renal pelvis, calices, and collecting tubules (weeks 5-8)
first 4 divisions of uteric bud merge and form major calyces (next 4 - minor calcyces)
nephrons develop mostly in 3rd trimester, before birth
excretory part includesnephron - bowman's capsule, PCT, LOH, DCT (develops from metanephros)
conducting part includescollecting tubules, minor/major calyces, pelvis of ureter, and ureter
what must become continuous to form the uriniferous tubulesmetanephric tubules and collecting tubules
development of kidney occurs in the pelvis
kidneys start at with their hila facing ? and receive branches of the ?ventrally; common iliac artery
relative ascent of the kidneys is due to caudal growth of the embryo
with kidney ascent, there is a 90 degree rotation to bring hila medially and kidneys end in lumbar region (differential growth)
after common iliac artery, kidneys receive blood supply fromlower aorta, middle aorta, suprarenal glands (stop further acent of kidneys)
by week 9, the kidneys are what way directionally?anteromedial
arteries that persist from kidney ascent are calledaccessory renal arteries or end arteries
accessory arteries are locatedabove or below hilum and may enter kidney directly at upper or lower pole
if accessory renal arteries enter kidney at lower pole, crossing over the ? may occur, resulting in ?ureter; obstruction of ureter --> hydronephrosis
potential implications of end arteriesif damaged, ischemia of the part of the kidney supplied