Embryology

Question 1

Male & female homologous structures developing from:

Urogenital sinus

Answer 1

M: Prostate, bladder, urethra, Cowper’s or Bulbourethral gland

F: Skene’s glands, bladder, urethra, lower ⅔ vagina, Bartholin’s gland

Question 2

Male & female homologous structures developing from:

Genital tubercle

Answer 2

M: Penis, bulb of penis, glans penis, crus of penis

F: Clitoris, vestibular bulbs, clitoral glands, clitoral crura

Question 3

Male & female homologous structures developing from:

Gubernaculum

Answer 3

M: Gubernaculum testis

F: Round ligament of uterus

Question 4

Male & female homologous structures developing from:

Urogenital folds

Answer 4

M: spongy urethra

F: labia minora

Question 5

Male & female homologous structures developing from:

Labioscrotal folds

Answer 5

M: Scrotum

F: Labia majora

Question 6

Male & female homologous structures developing from:

Mesonephric (wolffian) ducts

Answer 6

M: Rete testis, epididymus, vas deferens, seminal vesicle

F: Rete ovarii, Gartner’s duct

Question 7

Male & female homologous structures developing from:

Paramesonephric (mullerian) ducts

Answer 7

M: Appendix testis, prostatic utricle

F: Fallopian tubes, uterus, upper ⅓ vagina

Question 8

Which cell originates 2 haploid cells in male & female?

Answer 8

Primary spermatocyte

Primary oocyte

Question 9

Number of chromosomes & chromatids in a pre-antral oocyte?

Answer 9

2n, 4c (46 chromosomes, 2 copies of each chromosome)

Question 10

Number of chromosomes & chromatids in an oocyte just before ovulation?

Answer 10

• 1n, 2c (23 chromosomes, 2 copies)
• Secondary oocyte + 1^st polar body

Question 11

What is most important to prevent polyspermia?

Answer 11

Cortical reaction

Exocytosis of cortical granules from the ooplasm and renders the zona refractory to penetration by more than a single sperm