Question 12

Antidiuretic hormone is not a tropic hormone.

Tropic hormones are those that stimulate other endocrine glands to release their hormones. Antidiuretic hormone (ADH) primarily regulates water balance in the body rather than stimulating other glands.

A) Somatotropin

Somatotropin, also known as growth hormone, is not classified as a tropic hormone because it primarily acts directly on tissues to promote growth rather than stimulating other glands. However, it does play a role in metabolic processes.

B) Follicle-stimulating hormone

Follicle-stimulating hormone (FSH) is a tropic hormone as it stimulates the gonads to produce sex hormones and facilitate gamete production. This direct stimulation of other endocrine glands classifies it firmly within the tropic category.

C) Antidiuretic hormone

Antidiuretic hormone (ADH) is primarily involved in regulating the body's water balance by acting on the kidneys to promote water reabsorption. It does not stimulate other endocrine glands, which disqualifies it from being a tropic hormone.

D) Thyroid-stimulating hormone

Thyroid-stimulating hormone (TSH) is a tropic hormone because it prompts the thyroid gland to produce and release thyroid hormones. Its role in stimulating another gland aligns perfectly with the characteristics of tropic hormones.

Conclusion

Antidiuretic hormone is definitively the correct answer as it does not stimulate other glands, unlike follicle-stimulating hormone and thyroid-stimulating hormone, which are both tropic hormones. Somatotropin, while it influences growth, does not act as a tropic hormone in the same manner. Thus, all other options either fit the definition of tropic hormones or primarily act on target tissues.