Question

Explain the development of sex organs in men and female.

Answer 1

Hint: The development of the reproductive system is a part of prenatal development. Around the fourth week of the fetus, gonads differentiate into either testes or ovaries.

Complete Answer:
Internally there are two undifferentiated gonads and two pairs of parallel ducts: Wolffian(develops into parts of the male reproductive system, such as the epididymis and the vas deferens) and Müllerian ducts (forms the female internal sexual organs).
(I) If testes are developed, the hormone they secrete causes the Müllerian duct to degenerate and almost vanish and causes the Wolffian duct to develop into the sperm-carrying tubes and related organs.
(II) If ovaries are developed, the Wolffian duct degenerates, and the Müllerian duct elaborates to form the fallopian tubes, uterus, and part of the vagina. The external genitalia starts changing according to the sex.

- The genital projection becomes either a penis or a clitoris. In the female, the groove below the clitoris remains open to form the vulva. The folds on both sides of the groove become the inner lips of the vulva (the labia minora).
- In the male these folds grow together, converting the groove into the urethral tube of the penis. The ridge-like swellings on either side remain apart in the female and constitute the large labia (labia majora), but in the male, they grow together to form the scrotal sac into which the testes subsequently descend.
- During puberty, the reproductive system matures and the secondary sexual characteristics appear. The ovaries and testes begin producing much larger amounts of hormones.

Note: If the embryo has XX chromosomes, the primordial gonad cells proliferate to form ovaries in which the primary oogonia will develop. However, if the embryo has XY chromosomes, then the gene called SRY (Sex-Determining gene on Y-chromosome), present on Y-chromosome will initiate a cascade of a process to start the development of testes.