Gonads - Definition, Function & Hormones MCQ - Practice Questions with Answers

• The gonads are the sex glands; the ovaries and the testes. 
• They produce ova and sperm respectively but also secrete hormones.
• They develop from the mesoderm of the embryo. 

Ovaries:

• The ovaries are located in the pelvic cavity in close proximity to the oviducts and uterus.
• The following hormones are secreted by gonads:
  • Oestrogens
  • Progesterone
  • Relaxin
  • Inhibin/Actin

Oestrogens: 

• These are secreted by the cells of Graafian (ovarian) follicles. 
• It stimulates the development of female secondary sex characteristics during puberty and maintains them through the reproductive years of adult life. 
• It also stimulates maturation of ova (in the ovaries) and development of the uterine epithelium and the mammary glands.

Progesterone:

• It is secreted by the corpus luteum of the ovary. 
• It stimulates further development of the uterine epithelium and mammary glands.
• It is also required for the formation of the placenta and for the maintenance of pregnancy.

Relaxin:

• It is secreted by the corpus luteum only during the later stages of pregnancy.
• It helps to soften ligaments, especially those that hold the pubic symphysis together. 
• It may also affect other ligaments.

Inhibin/Actin:

• Inhibin/actin is secreted by the corpus luteum. 
• Inhibin hormone inhibits and actin hormone activates the FSH and LH production.
   

• A pair of testes is situated in the scrotum of male. 
• The connective tissue present between the seminiferous tubules in the testis contains small clusters of endocrine cells called interstitial cells or Leydig’s cells. 
• These cells secrete various male sex hormones called androgens. 
• The principal androgen is testosterone.
• Testosterone:
  • It stimulates the growth and development of male secondary sex organs.
  • Testosterone also stimulates the formation of sperm in the seminiferous tubules of the testes.
  • This hormone promotes the growth of many body tissues such as bones and muscles.