Which of the following is sex hormone ?

Question

Accepted Answer

The correct option is 3:
Testosterone and Estrogen are correctly identified as the sex hormones among the given choices. These hormones are classified as steroid hormones, meaning they are derived from cholesterol, and their primary function is to regulate sexual development, drive, and reproduction. Testosterone is the principal androgen, predominantly synthesized by the Leydig cells in the testes of males, but also in the adrenal glands and ovaries. It drives the development of male primary sex characteristics during puberty, such as the growth of the penis and testes, and secondary characteristics like deepening of the voice, body hair growth, and increased muscle mass. Estrogen, primarily in the form of estradiol, is the main female sex hormone, produced mainly by the ovarian follicles. Estrogen is crucial for the development of female secondary sex characteristics, including breast growth and the widening of the hips, and plays an indispensable role in regulating the menstrual cycle and supporting pregnancy. Both hormones are fundamental for gamete production and the maintenance of reproductive health in their respective sexes.

The incorrect option is 1:
Thyroid stimulating hormone, or TSH, is not a sex hormone. TSH is a glycoprotein hormone produced and secreted by the anterior pituitary gland, which is located at the base of the brain. Its primary and singular function is to act upon the thyroid gland, stimulating it to produce and release the thyroid hormones, Thyroxine (T4) and Triiodothyronine (T3). These thyroid hormones are critical regulators of the body's overall metabolism, energy levels, growth, and development across nearly all tissues. Therefore, TSH is correctly categorized as a tropic hormone, meaning it acts on another endocrine gland, rather than being directly involved in reproductive or sexual differentiation.

The incorrect option is 2:
Insulin is categorized as a metabolic hormone, and not a sex hormone. This peptide hormone is produced by the beta cells within the islets of Langerhans in the pancreas. Insulin's main role is to regulate the concentration of glucose in the blood, primarily by facilitating the uptake of glucose from the bloodstream into cells of the liver, muscle, and fat tissue for use as energy. Furthermore, it promotes the storage of excess glucose as glycogen and fat. Disruption of insulin production or function leads to conditions like diabetes mellitus. While essential for overall energy metabolism that supports all bodily functions, insulin has no direct role in establishing or maintaining primary or secondary sexual characteristics.

The incorrect option is 4:
Parathormone, also known as parathyroid hormone or PTH, is certainly not a sex hormone. This is a crucial hormone for mineral homeostasis, secreted by the small parathyroid glands located in the neck near the thyroid. The main function of parathormone is to maintain blood calcium and phosphate levels within a very narrow range. It achieves this by promoting the release of calcium from bone, increasing calcium reabsorption by the kidneys, and enhancing the activation of Vitamin D, which in turn boosts intestinal calcium absorption. Therefore, PTH’s actions are entirely focused on regulating calcium metabolism and bone health, placing it distinctly outside the category of hormones that govern sexual function and reproduction.