Development of the Urinary System Flashcards
intermediate mesoderm
nephrotome.
gives rise to the nephric structures of the embryo, portions of the suprarenal glands, gonads, and genital duct system
urogenital ridge
longitudinal elevation of mesoderm from transverse folding
divisions of urogenital ridge
nephrogenic cord–urinary system
gonadal ridge– genital system
three sets of nephric system that develop craniocaudally from nephrogenic cord
pronephroi–rudimentary and nonfunctional
mesonephroi– functions briefly during the early fetal period, excretory units and ducts
metanephroi–forms the permanent kidneys, most caudal
parts of the pronephric ducts used by next set of kidneys
mesonephric ducts, creates metonephric diverticulum (or uteric bud)
mesonephroi
excretory organs that appear late in 4th week, caudal to pronephroi. well developed, interim kidneys.
parts of the mesonphric kidneys
glomeruli and tubules
tubules open into bilateral mesonephric ducts (from pronephric ducts)
embryonic precursors to the efferent ductules of the testes
mesonphric tubules
functional adult derivatives of the mesonephric tubules
efferent ductules of testis
paradidymis
epoophoron
paroophoron
where do mesonphric ducts open into?
urogenital sinus (cloaca)
adult derivative of mesonephric ducts
appendix of epididymis/vesiculosa
duct of epididymis/epoophoron
ductus deferens/longitudinal duct; gartner duct
ureter, pelvis, calices, and collecting tubules of kidneys
ejaculatory duct and seminal gland
two parts of the metanephroi
excretory–metanephrogenic blastema (metanephric mass of mesenchyme), derived from caudal part of the nephrogenic cord
collecting–ureteric bud (metanephric diverticulum), from mesonephric duct near its entrance into cloaca
reciprocal induction
branching of the urteric bud– dependent on induction by the metanephric mesenchyme
differentiation of the nephrons depends on induction by the collecting tubules.
derivatives of nephronic cord and mesonephric duct as two functional parts of kidneys
nephronic cord–excretory, metanephrongenic blastema
mesonephric duct–collecting, uretic bud
collecting portion of kidney (ureteric bud)
ureter renal pelvis major and minor calyces collecting ducts collecting tubules
excretory portion (nephron) (metanephric blastema)
bowman’s capsule
proximal convoluted tubule
loop of henle
distal convoluted tubule
the second branching of ureteric bud and it’s stalk
stalk of ureteric bud= ureter
5-8=minor calices
second set of branching make minor calices coalesce via intussusception
development of the excretory portion of kidney
caudal part of the nephrogenic cord–>metanephrogenic blastema–>(meta)nephric vesicles elongate to (meta)nephric tubules which develop into the nephron (proximal/distal convoluted tubules, bowman’s capsule, loop of henle) due to invagination of proximal ends of glomeri
what constitutes a nephron
proximal and distal convoluted tubules, nephron loop (henle loop), glomerulus and capsule
when is the upper limit of glomeruli reached?
32nd week, nephron formation is complete at term. 2 million nephrons.
week nine, glomerular filtration begins
which convoluted tubule contains arched collecting tubule
distal convoluted
urine productivity
10-11th week begins
late pregnancy–500ml of urine added daily
700-1000ml by week 37
positional changes of kindeys
metanephric structures in pelvis, ventral to sacrum
ascent
medial rotation
retroperitoneal positioning
relocation of the kidneys to the abdomen and movement farther apart
disproportionate growth of the embryo’s body caudal to the kidney. this makes them contact suprarenal gland. normal adult position by 9th week.
during kidney ascension, they also
medially rotate 90 degrees, ventral location of hilum is changed to anteromedially
changes in blood supply to the kidneys
renal arteries (common illiac branches) from descending abdominal aorta distal end of aorta new branches from the aorta and the caudal branches of renal vessels disappear=permanent renal arteries