Neurosonology Practice Exam

This item tests how glands communicate signals—whether they use systemic hormonal release (endocrine) or other modes. The thyroid is an endocrine gland because it releases thyroid hormones into the bloodstream, and these hormones travel throughout the body to regulate metabolism and development. Exocrine glands secrete into ducts or surfaces, which is not how the thyroid operates. Neural signaling uses nerve impulses rather than circulating hormones, and paracrine signaling affects nearby cells locally, not distant tissues. Since thyroid hormones act systemically via the blood, the thyroid fits the endocrine category.