Urogenital System: Embryology Flashcards
When does the Pronephros appear?
Appears: 4th week and then degenerates
When does the Mesonephros appear?
Late in the four week and is functional until the 11th week
When does the Metanephros appear?
Appears during the 5th week; prior to degeneration of the Mesonephros.
It is functional and definitive
What is the Uteric Bud, and what structures does it give rise to?
Uteric Bud (Aka: Metanephric Bud), outgrowth of the Mesonephric Duct.
Gives rise to the Ureter, Renal Pelvis, Major & Minor Caycles and Collecting tubules
What are the two sources that the Kidney is dervied from and what are the general aspects of the kidney that they give rise to.
1) Metanephric Mesoderm (Metanephric Blastema): Excretory units
2) Uteric Bud (Metanephric Duct): Collecting system
What are the specific structures derived from the Uteric Bud?
Collecting System:
Ureter, Pelvis, Major Calyces, Minor Calyces, and Collecting Tubules
What are the specific structures derived from the Metanephric Blastema?
Excretory Units: Renal Vesicles, Bowman’s Capsule, PCT, DCT, and Loop of Henle
What are some of the characteristics of Renal Agenesis?
- Affects males more than females
- Other Kidney will hypertrophy to compensate
- Suspected in infants w/ one Umbilical A.
- Asymptomatic
What is the embryological mechanism and some of the characteristics of bilateral renal agenesis?
1) Uteric Bud didn’t form or degenerated
2) Associated w/ Oligohydraminos & Seen in 20% of Potter sequence patients
What are some of the characteristics of a Duplex Kidney?
Duplex Kidney: Results from abnormal division of the uteric bud.
X-ray: See two ureters
The adult position of the kidneys is achieved by what timeline?
Also, where do the fetal kidneys develop?
Adult Position: 9 weeks
Fetal Kidney: develops in the Pelvis
The ascent of the kidney is due to what?
Caudal growth in the fetus
What are some of the charaacteristics associated with Autosomal recessive Polycystic Kidney disease?
Also, what is the primary mutation in this disease?
1) Both kidneys contain many small cysts.
- Renal insufficiency
- 25% associated with pulmonary hypoplasia
2) Mutation of the PKHD1 gene
What is the ureter derived from?
Mesonephric and Metanephric Ducts
What is the bladder dervied from?
Hindgut endoderm
What is the Trigone dervied from?
Mesoderm
Specially, the fusion of the lower parts of the mesonephric ducts.
What are the Vas Deferens derived from?
Persistence of the Mesonephric ducts in males
What is the Allantois and some of its characteristics?
Also, what does it become?
Allantois: It is an overextension of the bladder (derived from the urogenital sinus)
It will go into the umbilical cord.
Becomes the Urachus (fibrous remnant), which then becomes the median umbilical ligament
What seperates the Urogenital Sinus and the Anal Canal?
Urorectal septum
What are the three regions of the Urogential Sinus?
1) Vesicle Part:
2) Pelvis Part:
3) Phallic Part
What does the Vesicle part of the Urogenital Sinus produce?
The bladder
What does the pelvic part of the Urogenital Sinus produce?
Females: Urethra
Male: Prostatic Urethra and Membranous Urethra
What does the Phallic part of the Urogenital Sinus produce?
Females: Vaginal vestibule
Males: Spongy Urethra
What does the Genital Tubercle give rise to?
Penis or Clitoris
A urachal cyst is due to persistence of the what structure?
Allantois
What are some characteristics associated with a patent Urachus?
Pee coming out of the belly button
What are some characteristics of a Urachal sinus?
Deep valley at the belly button
What are some characteristics of Exstrophy of the bladder?
Also, what is the embyrological mechanism for this?
1) Defective close of the ventral abdominal wall.
- exposure of the mucosa of the posterior wall of the bladder
2) Not enough Mesoderm migrating; improper folding of the lateral wall (4th week)
What are some of the characteristics associated with Epispadias?
What is the embryological mechanism?
1) Two penises or opening on dorsal side
2) Improper location of the genital tubercle; occurring caudally to the clochal membrane
What structure is the Medulla dervied from?
Neural Crest; Chromaffin system
What structure is the Capsule of the suprarenal glands derived from?
Mesonephric mesoderm
What is the cortex of the suprarenal gland derived from?
Coelomic Epithelium (Somatic mesoderm)
