EX3 Embryology - Urinary System Flashcards
What germ layer is the urinary system derived from
intermediate mesoderm
True or False
The intermediate mesoderm becomes retroperitoneal
True
What is first formed from the intermediate mesoderm
bilateral urogenital ridge
What are the two portions of the urogenital ridge
nephrogenic cord
gonadal ridge
This is the lateral portion of the urogenital ridge; responsible for urinary structures
nephrogenic cord
This is the medial portion of the urogenital ridge; responsible for genital structures
gonadal ridge
What are the three stages of kidney development
pronephros
mesonephros
metanephros
This stage of kidney development begins early in week 4 and is present for only a few days
pronephros
This stage of kidney development is from weeks 4-10, becoming functional at week 6
mesonephros
This stage of kidney development is from week 5 and beyond, developing into the definitive kidney and is function at weeks 9/10
metanephros
The pronephros develops bilaterally in which region
cervical
The pronephros consist of what type of tissue
a solid rod of intermediate mesoderm connected to epithelial-lined buds
The mesonephros develops in which region
throacolumbar
What does the mesonephros use to guide its formation
the pronephros
What three things make up the mesonephros
mesonephric duct
mesonephric tubules
mesonephric vesicles
The mesonephric duct functions as what in adults
the ductus deferens in males
The mesonephric tubule functions as what in adults
efferent ductules of testes
The mesonephric tubule elongates to act as what
the tubular part of nephron
The mesonephric vesicle functions as what
Bowman’s casule; contains the glomerulus
True or False
There are 45-50 glomeruli per mesospheric kidney
False; there are only 10-15
In which direction does the mesonephros grown
caudally toward the cloaca
Once the mesonephros contacts the cloaca what happens
it hollows out (caudal to cranial)
the ureteric bud (metanephric diverticulum) forms
What initiates the formation of the metanephros
the mesonephros contacting the cloaca
What are the two components of the metanephros
ureteric bud (metanephric diverticulum) metanephrogenic blastema
The metanephrogenic blastema is derived from what tissue
mesenchyme of nephrogenic cord
The ureteric bud gives rise to what portion of the kidney
collecting portion; ureter renal pelvis major and minor calyces collecting tubules
The blastema gives rise to what portion of the kidney
extretory protion; distal convoluted tubule loop of hence proximal convoluted tubule Bowman's capsule
What is reciprocal induction
communication between the ureteric bud and blastema is required for kidney development
True or False
The kidneys descend into proper position
False; they ascend to reach the suprarenal glands
What is the original blood supply of the kidneys
common iliac artery
What is the final blood supply of the kidneys
right and left renal artery
Failure of the temporary blood supply of the kidneys to regress leads to what
accessory renal arteries common occurrence (~25% of adults have 2-4 aa)
This is when the poles of the kidneys (usually inferior) fuse together blocking the ascent due to blockage of the IMA
horseshoe kidney
The urorectal septum divides the cloaca into what components
urogenital sinus (ventrally) anorectal canal (dorsally)
What urogenital sinus derives into what components in males and females
urinary bladder (and allantosis) urethra
The urogenital sinus derives into what components in males
prostate
bulbourethral glands
The urogenital sinus derives into what components in females
vestibule or vagina
vestibular glands
This closes off to form the urachus (fibrous cord)
allantosis
This coveres the obliterated urachus in the adult
median umbilical fold
What type of urachal abnormalities can exist
urachal cyst
urachal sinus
urachal fistula
This develops from the distal portions of the mesonephric ducts as they are incorporated into the posterior wall of the urinary bladder
trigone
What is meant by “water under the bridge”
the ureter is below the mesenepric duct (future vas deferens)
This results from failure of anterior abdominal wall to close
urinary bladder exstrophy (exposed to enternal environment)
This results from the failure of one or both of the kidneys to form (ureteric bud fails or reciprocal induction fails)
renal agenesis
Renal a genesis can lead to what
oligohyraminos (too little amnionic fluid) potter syndrome (from bilateral)
True or False
Potter syndrome is 100% fatal
True; leads to the lack of development of other organs and causes deformities
True or False
A crosses renal ectopia kidney (2 on one side) is more common than a pelvic kidney
False; a crosses renal ectopia is 1/10,000 and a pelvic kidney is 1/1,000
