Development Of Reproductive System

Question 1

What occurs during weeks 1-6?

Answer 1

Indifferent embryo

Question 2

What begins in week 7?

Answer 2

Sexual differentiation

Question 3

When can female and male genitalia be recognized?

Answer 3

Week 12

Question 4

When is phenotypic differentiation complete?

Answer 4

Week 20

Question 5

Both the mesonephric and paramesonephric ducts form in what?

Answer 5

Intermediate mesoderm of the urogenital ridge

Question 6

What are mesonephric (Wolffian) ducts?

Answer 6

Part of early kidney development (serve as early collecting ducts for the mesonephric kidney)
Open into the urogenital sinus
Will form epididymis, vas deferens, seminal vesicle and ejaculatory duct

Question 7

What are the paramesonephric (Mullerian) ducts?

Answer 7

Open to the coelomic cavity and caudally meet with each other when attaching to the urogenital sinus
Will form oviduct, uterus and upper vagina

Question 8

Describe mesonephric duct development in males

Answer 8

Leydig derived testosterone drives mesonephric ducts to form efferent ductules (from remaining mesonephric tubules), epididymis, vas deferens and seminal vesicle

Question 9

How do Sertoli cells contribute to the hormonal control of male differentiation?

Answer 9

Generate AMH that drives loss of paramesonephric ducts + androgen binding factor (spermatogonia -> spermatozoa)

Question 10

What do fetal Leydig cells produce and how does this contribute to hormonal control of male differentiation?

Answer 10

Produce testosterone (week 8-10 and driven by placental HCG) causing differentiation of mesonephric duct into epididymis, vas deferens and seminal vesicle

Question 11

A portion of testosterone secreted from fetal Leydig cells is converted to what?

Answer 11

Dihydrotestosterone (DHT) by 5-alpha reductase

This drives development of external genitalia (penis, scrotum, prostate)

Question 12

What is the seminal vesicle?

Answer 12

Buds from mesonephric duct (intermediate mesoderm of urogenital ridge)

Question 13

What does the prostate gland bud from?

Answer 13

Endoderm of UG sinus in region of pelvic urethra (week 10)

Question 14

What do the bulbourethral glands form from?

Answer 14

Endodermal buds

Question 15

Describe uterus formation

Answer 15

Fusion of inferior paramesonephric ducts form the uterus

Uterine tubes are the unfused superior portion of the paramesonephric ducts

Question 16

What are some uterus anomalies?

Answer 16

Double uterus (didelphys), bicornate uterus (incomplete fusion; two bodies one cervix), double uterus double vagina, septated uterus, unicornate uterus (one uterine tube formed) and cervical atresia

Question 17

What does the superior gubernaculum develop into in females?

Answer 17

Round L of ovary (connects ovary to uterus)

Question 18

What does the inferior portion of the gubernaculum form in the female?

Answer 18

Round L of uterus (connects uterus to labia majora)

Question 19

What do the indifferent gonads develop into?

Answer 19

Testis and ovary

Question 20

What are the primordial germ cells?

Answer 20

Spermatogonia and oocytes

Question 21

What does the urogenital sinus form?

Answer 21

Prostatic and membranous urethra, prostatic gland, bulbourethral glands in males
Membranous urethra, urethral/paraurethral glands and greater vestibular glands in females

Question 22

What does the genital tubercle form?

Answer 22

Glans penis, corpus cavernosa and spongiosum of penis

Glans clitoris, corpus cavernosa of clitoris, bulbospongiosum of vestibule

Question 23

What do the urogenital folds, urogenital plate and glans plate form?

Answer 23

Penile urethra/ventral part of penis

Labia minora in females

Question 24

What do the labioscrotal folds form?

Answer 24

Scrotum in males

Labia majora in females