Question

Which one of the following pairs of organs includes purely endocrine glands?

• A. Parathyroid and adrenal
• B. Pancreas and parathyroid
• C. Thymus and testes
• D. Adrenal and ovary

Answer 1

The correct option is A Parathyroid and adrenal

The parathyroid and adrenal glands are purely endocrine glands. They pour their secretions (hormones) into the blood. The parathyroid glands secrete the parathyroid hormone. The adrenal gland is composed of the medulla and the cortex. The adrenal medulla secretes adrenaline and noradrenaline. The adrenal cortex secretes hormones called corticoids.

The pancreas is a heterocrine gland. Its secretion of the hormones insulin and glucagon into the blood is an endocrine function; and the secretion of enzymes into the digestive tract is an exocrine function.

The thymus is a part of both the endocrine system and the lymphatic system, because it secretes the hormones thymosins and T-lymphocytes differentiate inside it.

Testes and ovaries are both gonads and endocrine glands. The gonadal function of testes and ovaries is the production of gametes, sperms and eggs, respectively. The endocrine function of testes is that they produce the hormone testosterone. Ovaries produce the hormones estrogen and progesterone.