Genital Embryology Flashcards
Which ducts contribute to female genital development?
By default, mesonephric (wolffian) duct degenerates, and paramesonephric ducts develop.
What gene is responsible for male genital development?
SRY on Y chromosome. Produces testes-determining factor (TDF) –> testes develop.
What cells of the testes contribute to further male genital differentiation
Sertoli cells and Leydig cells
What role do Leydig cels play in male genital development?
Secrete testosterone, that stimulates development of mesonephric ducts.
What role do Sertoli cells play in male genital development?
Secrete Mullerian inhibitory factor - MIF - that suppresses development of paramesonephric ducts.
What are the derivates of the mesonephric ducts?
Develops into male internal structures (except
prostate)—Seminal vesicles, Epididymis,
Ejaculatory duct, Ductus deferens (SEED).
What is the remnant of mesonephric duct called in females?
Gartner duct
What are the derivatives of the paramesonephric ducts?
Develops into female internal structures—
fallopian tubes, uterus, upper portion of vagina
(lower portion from urogenital sinus).
What is the presentation of mullerian agenesis?
May present as 1°
amenorrhea (due to a lack of uterine
development) in females with fully developed
2° sexual characteristics (functional ovaries). Differentiate from imperforate hymen.
What does absence of Sertoli cells of MIF production cause?
Both male and female internal genitalia, and male external genitalia
What is the derivative of genital tubercle and urogenital sinus in males?
Male external genitalia and prostate
What induces formation of male external genitalia?
Testosterone converted to DHT by 5-a reductase.
DHT induces formation of male external genitalia and prostate.
What is the consequence of 5a reductase deficiency?
Male internal genitalia, ambiguous external genitalia until puberty, when increase in testosterone levels cause masculinization
What uterine anomalies may arise in development?
Septate uterus (incomplete resorption of septum) Bicornuate uterus (Incomplete fusion of Mullerian ducts) Uterus didelphys (Complete failure of fusion - double uterus, vagina, and cervix)
What is the effect of septate uterus on fertility?
Decreased
What is the effect of bicornuate uterus on ferility?
Incr risk of complicated pregnancy
What is the effect of uterus didelphys on fertility
Pregnancy still possible
What develops from the genital tubercle if exposed to DHT?
Glans penis, corpus cavernosum and spongiosum
What develops from the genital tubercle if exposed to estrogen?
Glans clitoris and vestibular bulbs
What develops from the urogenital sinus if exposed to DHT?
Bulbourethral glands and prostate gland.
What develops from the Urogenital sinus if exposed to estorgen?
- Greater vestibular glands of Bartholin.
- Urethral and paraurethral glands (of Skene)
What develops from the urogenital folds if exposed to DHT?
Ventral shaft of penis, penile urethra.
What develops from the urogenital folds if exposed to estrogen?
Labia minora
What develops from the labioscrotal swelling if exposed to DHT?
scrotum
What develops from the labioscrotal swelling if exposed to estrogen?
labia majora
What is hypospadias?
Opening of penile urethra on ventral (bottom) surface of penis.
What causes hypospadias?
Failure of urethral folds to fuse.
What is associated with hypospadias?
Inguinal hernia, cryptorchidism
What is epispadias?
Abnormal opening of penile urethra on dorsal (top) surface of penis.
What causes epispadias?
Faulty positioning of genital tubercle
What is associated with epispadias?
Exstrophy of the bladder
What happens to the gubernaculum in males?
anchors tests within scrotum
What happens to the gubernaculum in females?
Ovarian ligament + round ligament of the uterus
What happens to the processus vaginalis (evag of peritoneum) in males?
Forms tunica vaginalis
What happens to the processus vaginalis (evag of peritoneum) in males?
Obliterates
