Development -- Genital

Question 1

Genital system develops from

Answer 1

Urogenital ridge (Intermediate mesoderm):

• Lateral: Reproductive duct
• Medial: Genital, gonadal ridge

Question 2

Timeline of genital system (broad)

Answer 2

—Male & female morphological features do not develop until week 7

—Weeks 12-14 = recognizable features of external genitalia

—Week 20 = phenotypic differentiation is complete

Question 3

When and where do the indifferent gonads appear

Answer 3

During 5th week at genital/gonadal ridge

Question 4

SRY gene encodes for

Answer 4

testes determining factor (TDF)

Question 5

Testis cords forms

Answer 5

Rete testes and tubuli recti

Question 6

Testis cords contain

Answer 6

Primordian germ cells

Sustenacular (sertoli) cells: Secrete mullerian inhibiting factor (MIF)/ anti-Mullerian hormone (AMH)

Question 7

Mullerian inhibiting factor function

Answer 7

—Suppresses the development of paramesonephric ducts

Question 8

Mesoderm between testis cords:

Answer 8

Interstitial (leydig) cells

Question 9

Leydig cell function

Answer 9

Secrete testosterone

Question 10

Function of 5a reductase

Answer 10

Converts testosterone to dihydrotestosterone (DHT)

•DHT required for male external genitalia differentiation

Question 11

Fibrous band extending from caudal pole of testes to scrotum

Answer 11

Gubernaculum

Question 12

Peritoneal diverticulum that penetrates abdominal wall in inguinal region

Answer 12

Processus vaginalis (testes pull it down, testes posterior)

Question 13

Adult remnant of processus vaginalis

Answer 13

Tunica Vaginalis

Question 14

Cryptochordism

Answer 14

Undecended testes

Question 15

In ovary development, Primitive sex cords are replaced by

Answer 15

cortical cords

Question 16

In females, gubernaculum forms:

Answer 16

—Proper ovarian ligament

—Round ligament of the uterus

Question 17

Types of genital ducts (m/f)

Answer 17

Male: Mesonephric (wolffian) ducts

Female: Paramesonephric (mullerian) ducts

Question 18

Fusion of paramesonephric ducts forms:

Answer 18

uterovaginal primordium

Question 19

Mesonephric duct forms:

Answer 19

Epididymis

Ductus deferens

Seminal vesicle

Ejaculatory duct

Question 20

Mesonephric tubules

Answer 20

Efferent ductules of testes

Question 21

Paramesonephric duct remnant in males

Answer 21

Prostatic utricle

Question 22

Remnants of mesonephric ducts & tubules in females

Answer 22

Question 23

Cranial paramesonephric form

Answer 23

Uterine tubes

Question 24

Caudal paramesonephric ducts form

Answer 24

Fused in midline to form uterovaginal primordium

Forms uterus, cervix, and upper vagina

As a consequence, broad ligament is formed

Question 25

Sinus tubercle in women forms when:

Answer 25

Uterovaginal primordium contacts urogenital sinus – induces formation of sinovaginal bulbs

Question 26

What forms the lower vagina

Answer 26

The vaginal plate (formed by fusion of sinovaginal bulbs)

Question 27

Answer 27

Question 28

Lower urogenital sinus in males forms:

Answer 28

Proximal penile urethra, membranous urethra, & prostatic urethra

Question 29

Prostate gland forms

Answer 29

—Endodermal outgrowths from the prostatic urethra

Question 30

Bulbourethral gland forms from:

Answer 30

Endodermal outgrowths from the spongy urethra

Question 31

Scrotum forms from

Answer 31

Genital swellings enlarge and grow toward each other until they fuse

Question 32

Answer 32

Question 33

Female urethra forms from:

Answer 33