Renal Embryology Flashcards
What gives rise to the kidneys and genitalia
Intermediate mesoderm
What specifically gives rise to the nephron
The mesonephric tube
What are the three kidneys in order of development
Pronephros Mesonephros (functional) Metanephros (definitive/true)
When does the pronephros form and degenerate
Forms and degenerates in the 4th week
Where does the pronephros form
In the cervical region of the embryo and heads to the cloaca
When does the mesonephros appear and when it is functional until
Appears in late 4th week and is functional until 11 - 12 weeks
What does the mesonephros ultimately become
The male genitalia
When does the metanephros form
Week 5
What are the two parts of the metanephros
Ureteric bud
Aka: metanephric duct aka metanephric diverticulum
Metanephrogenic blastema (mass)
What does the glomeruli arise from
The dorsal aorta
Bowman’s capsule and the mesonephric tubules arise from what
Intermediate mesoderm
The mesonephric duct induces what
mesonephric Nephrons to form in the adjacent nephogenic cord
The ureteric bud is an outgrowth of what
The mesonephric duct
What is the metanephric blastema derived from
The nephrogenic cord
What does the ureteric bud give rise to
The ureter
Renal pelvis
Major and minor calyces
Collecting tubules
What does the metanephric blastema GRT
Renal vesicles
Bowman’s capsule
PCT/DCT
LoH
The ureteric bud contacts the metanephric blastema and gives rise to what first
The renal pelvis
What does the ureteric bud GRT second and third
Major and then minor calyces
What does the metanephros nephron originate as
A vesicle within the blastemic cap surrounding the ampulla of the collecting duct
What is the role of the formation of the collecting ducts
When these are formed from the ureteric bud, it causes a signal to be sent to the metanephros blastema to begin production of the nephron and rest of the kidney system
Who does unilateral renal agenesis usually affect? And what is presented
Usually affects males
Usually no L kidney
What happens in bilateral renal agenesis? What causes this
No kidneys
Usually caused by oligohydramnios
What does a duplex kidney result from
Abnormal division of the ureteric bud
When are the kidneys positioned by in adults
Week 9
What causes the kidneys to ascend in the fetus
The caudal growth of the embryo
During the ascent, kidneys do what? What does this allow for
Rotate 90 degrees. This allows for the hilum to be facing the Ao.
What causes a pelvic (ectopic) kidney
Results from the lattice of vessels from the posterior cardinal V. Blocking the ascent
What causes a horseshoe kidney
The inferior poles of the kidney are fused, and thus the kidney is unable to get pass the IMA and stays at L3
Define autosomal recessive polycystic kidney disease
Occurs due to a mutation of the PKHD1 gene
Both kidneys have small cysts
Renal insufficiency results from this
Can be associated with pulmonary hypoplasia/oligohydramnios
Define multicystic dysplastic kidney disease
Abnormal development of the renal system
The cysts are a dilatation of the LoH, this could be an issue with the metanepheros blastema
In the adult, the ureter only arises from what
The metanephric duct (ureteric bud)
The bladder is formed from what
Hindgut Endoderm
What is the trigone and what is it formed from
Is the incorporation of the mesonephric duct into the bladder wall
Comes from mesoderm
What makes up the urogenital and anal membrane
Endo/ecto -derm
What separates the urogenital membrane from the anal membrane
The uro-rectal septum
Define the allantois and what does it GRT
This is an extension of the hindgut endoderm into the bladder
Gives rise to the urachus and the median umbilical L.
What specifically gives rise to the bladder (within hindgut endoderm)
The vesicle part of the urogenital sinus
What does the pelvis part of the urogenital sinus GRT
Urethra (f) Prostatic urethra (m)
What does the phallic part of the urogenital sinus GRT
Lining of the vaginal vestibule (f)
Spongy urethra (m)
When does exstrophy of the bladder occur?
During body folding of the 4th week
What causes exstrophy of the bladder
Defective closure of the ventral abdominal wall due to the mesoderm not migrating between the endo/ecto -derm on the anterior body wall
What is the chromaffin system formed from
NC Cells
What is the surarenal caspule formed from
Meonephric mesoderm
How does the cortex of the AG form
Comes from the coelomic epithelium of the somatic mesoderm in the 6th week.
First wave makes the fetal cortex
Second wave makes the adult cortex
