1. Kidney embryology Flashcards
intermediate mesoderm gives rise to
urogenital ridge
Urogenital ridge gives rise to … (and then )
nephrogenic ridge –> develops into 3 steps of nephric structure —> a. pronephros b . mesonephros c. metanephros
sets of nephric structure ( and area)
- pronephros ( upper - cranial most)
- mesoneprhros ( middle)
- metanephros ( lower -caudal most)
pronephros - time
apperas at week 4 and then degenerates
pronephros - function
not functional in humans 5
pronephros develops by
the differentiation of mesoderm within the nephrogenic cord to form pronephric tubules and the pronephric duct
mesonephros develops by
the differentiation of mesoderm within the nephrogenic cord to form mesonephric tubules and the mesonephric duct (wolffian duct)
mesonephric duct is AKA
Wolffian duct
mesonephros function
- interim kidney for 1st trimester
2. later contributes to male genital center ( mesonephric duct)
mesonephros - regression
most of mesonephric tubules regress, but the mesonephric duct ( Wolffian duct ) persists to open into urogenital sinus
Metanephros time
1st appears in5th week of gestation –> nephrogenesis continuous through 32-36 weeks of gestation
metanephros is functional in fetus in (time)
week ten
metanephros is consist by
- ureteric bud
2. metanephric parenchyma ( metanephric blastema)
metanephros is consist by … ( developed by)
- ureteric bud –> derived from caudal end of mesonephric duct
- metanephric parenchyma ( metanephric blastema)–. condensation of mesoderm within nephrogenic cord
metanephros is consist by (gives rises generally )
- ureteric bud –. collecting system
2. metanephric parenchyma ( metanephric blastema)—> nephron
ureteric bud gives rise to ( explain )
collecting system : it penetrates metanephric mesoderm to form the ureter, pelvises , calyces, collectind ducts
ureteic bud is fully canalized at
10th week
aberant interaction between ureteric bud and metanephric mesoderm may result
several congenital malformations of kidney
renal - DCT
distal concoulate tubule
MC of renal system obstruction ( hydronephrosis ) in fetus (and why)
ureteropelvic junction - last to canalize
kidney embryology - last to canalize
ureteropelvic junction
• The kidneys of a 4-week-old human embryo are examined. The development of which structure is expected to be seen?
The pronephros
• After week 4, what happens to the pronephros?
The pronephros degenerates
During which trimester of fetal development does a structure that eventually contributes to the male genital system arise?
During the first trimester, the mesonephros, which later contributes to male genital system, begins to develop
• What fetal structure functions as the interim kidney for the first trimester?
Mesonephros
• A researcher wishes to physically block development of the ureteric bud. Where must he stall development?
The caudal end of the mesonephros
What adult structures in the urinary tract are derived from the ureteric bud?
• Collecting ducts, calyces, pelvises, and ureters
• What adult structures in the urinary tract are derived from the metanephric mesenchyme?
Structures in the kidney, from the glomerulus to the distal convoluted tubule
• What is the most common cause of hydronephrosis in a fetus? Why?
Ureteropelvic junction obstruction; the ureteropelvic junction is the last structure to canalize
• The interaction of which two structures/tissues in the developing kidney induces proper differentiation and formation of the renal tubules?
Ureteric bud and metanephric mesenchyme (aberrant interaction leads to congenital malformations)
• The ____ (pronephros/mesonephros/metanephros) appears at week 5 of gestation and is permanent.
Metanephros
• After formation of the ____, nephrogenesis continues through weeks 32–36 of gestation.
Metanephros
