UG Development 4 Flashcards
Describe the embryological/anatomical basis of ectopic pregnancy, hypospadius, cystic structures around the testis or ovary, and fistulas/cysts/sinuses related to abnormal UG sinus development.
1
Q
What happens to the genital tubercle and labioscrotal folds in the male and female?
A
- Male - genital tubercle becomes the penis and labioscrotal folds become the scrotum
- Female - genital tubercle becomes the clitoris and labioscrotal folds become the labia majora
2
Q
What are the origins of the penile urethra?
A
- Ventral fusion of the phallic part of the UG sinus
- invaginates in the ventral surface of genital tubercle
- UG folds incorporated into ventral surface
- Epithelial invagination of the tip of the penis
- forms the navicular fossa
3
Q
In the female what happens to the urogenital sinus and folds?
A
-
Lower UG sinus becomes:
- urethra
- vestibule
- greater vestibular glands
- paraurethral glands
- Urogenital folds become the labia minora
4
Q
What happens in hypospadius?
A
- A condition in the newborn where the penile urethra is open to the ventral surface of the penis
- Occurs if the two primordia of the penile urethra do not join
5
Q
How do fistulas/cysts/sinuses form?
A
- Improper division of the cloaca results in fistulas:
-
Female - between rectum and:
- perineum
- vestibule
- vagina
-
Male - between rectum and:
- perineum
- urethra
- bladder
-
Female - between rectum and:
- Cysts, sinus, fistulas of the allantois if it fails to fully become the urachus
6
Q
How do Gartner cysts form?
A
- From the improper closure of the mesonephric ducts (Gartner ducts)
- Paramesonephric duct cysts are the equivalent in males