Question 15

Antidiuretic hormone is not a tropic hormone.

Antidiuretic hormone (ADH) primarily functions to regulate water balance in the body, rather than stimulating other endocrine glands. Unlike tropic hormones, which target other glands to release hormones, ADH acts directly on the kidneys.

A) Somatotropin

Somatotropin, also known as growth hormone, is not classified as a tropic hormone. It primarily stimulates growth and cell reproduction directly rather than influencing other endocrine glands to release hormones.

B) Follicle-stimulating hormone

Follicle-stimulating hormone (FSH) is a tropic hormone that stimulates the gonads to produce sex hormones and gametes. This hormone plays a crucial role in regulating reproductive processes, making it a classic example of a tropic hormone.

C) Antidiuretic hormone

Antidiuretic hormone (ADH) does not qualify as a tropic hormone because it does not act on other endocrine glands. Instead, it directly affects the kidneys to promote water reabsorption, thereby regulating fluid balance in the body.

D) Thyroid-stimulating hormone

Thyroid-stimulating hormone (TSH) is a tropic hormone that stimulates the thyroid gland to produce and release thyroid hormones. Its action on the thyroid makes it a prime example of how tropic hormones function to regulate other endocrine glands.

Conclusion

Antidiuretic hormone is definitively not a tropic hormone due to its direct action on the kidneys rather than influencing other glands. In contrast, follicle-stimulating hormone and thyroid-stimulating hormone are clear examples of tropic hormones because they stimulate other endocrine glands. Somatotropin, while significant in growth regulation, also does not fit the definition of a tropic hormone, solidifying option C as the correct choice.