Embryology Flashcards
which primitive layer do the urinary and reproductive systems develop from
the intermediate mesoderm
which ridge does the urinary tract develop from
nephrogenic
what ridge does the reproductive system develop from
gonadal ridge
What are the 3 stages of kidney development
pronephros
mesonephros
metanephros
when do pronephros form and when fo they degenerate
form in cervical region during week 4 and degenerate by the end of the week
where and when do mesonephros form
thoracic and upper lumbar regions- interim kidney until month 3
meonephric tubules develop and drain into wolffian duct of mesonephric duct which drains to cloaca
when do metanephros form
during week 5 and functional by end of 3rd month
what does the metanephric blastema form
intermediate mesoderm that forms excretory units- nephron like bowmands capsule, proximal convoluted tubules, loop of hence and distal convuluted tubules
what does the ureteric bud form
evagination of mesonephric duct, penetrates blastema and forms the duct system of collecting tubules, minor and major calyces and renal pelvis and ureter
Where do the kidneys form and when do they migrate
form in pelvis and ascend around week 9 to abdomen
do the kidneys lay in their original position when the ascend
they rotate about 90 medially
What does the urorectal septum divide
the cloaca into anterior urogenital sinus and posterior rectum/anal canal
What arises from the urogenital sinus
bladder and parts of urethra
what arises from the cranial portion of urogenital sinus
bladder and the urachus which forms median umbilical ligament
what forms the trigone region of urinary bladder
mesonephric duct
what does the middle portion (pelvic) of the urogenital sinus form in females? in males?
females it becomes the urethra
males it becomes the prostateic and membranous urethra
what forms from the caudal (phallic) portion of the urogenital sinus
males only- penile urethra
What arises from persistence of caudal renal aa during development
accessory renal aa that usually are asymptomatic but can compress ureter and cause hydronephrosis
What causes renal hypoplasia
inadewuate branching of ureteric bud and lack of differentiation of nephrons.
What is a types of renal hypoplasia
persistent fetal lobulation
What happnes in congenital cystic kidney disease whenn it is autosomal recessive
cysts form from collecting ducts- renal insufficiency
what happens in congenital cystic disease when it is autosomal dominant
cysts form from collecting ducts and nephron
what are kidney cysts
wise dilations of parts of the nephrons
what causes renal agenesis
ureteric bud fails to form and/or induce differentiation of the metanephric blastema
uni or bilateral
what primarlily causes potter sequence
bilateral renal agenesis
what does renal agensis resul in
oligohydramnios- fetus not urinating
what are secondary symptoms to oligohydramnios
hypoplastic lungs
potter facies- broad, flat nose, wide-set eyes, low-set ears, micrognathia
sometimes limb malformations like club foot
what is a horseshoe kidney
inferior poles fuse into pelvis and so ascent is blocked nu inferior mesenteric artery
what are ectopic kidneys
kidneys fail to ascend
What is the most comon malignant tumor of kidneys in children
wilms’ tumor present before age 5 due to muation in WT1 gene
How does one get a suplication of one ureter
splitting of uteric bud- someitmes can cause 2 kidneys
what is an ectopic ureter
two ureteric buds form and one is normal the other goes to abnormal site on bladder or urethra, vestibule, vagina
What occurs when the lumen of the allantois persists
urachal anomalies like a fistula, a sinus or cyst
what is a urachal fistual
entire lumen remains open so urine could leak from umbilicus
What is exstophy of the bladder
ventral body wall defect because lateral body walls do not fuse causing the mucosa to be exposed and presents with epsipadias
What is extrophy of the cloaca
ventral body wall defect when lateral body wall does not fuse causing inner epithelium to be exposed and the urorectal septum is also deficient causing exposure to rectum. imperforate anus
what is more severe extrophy of bladder or cloaca?
cloaca
