Biology 30 Nervous and Endocrine System Practice Test 2026 – Comprehensive Exam Prep

The main idea here is how the hypothalamus controls the anterior pituitary. The hypothalamus sends two types of chemical signals to the pituitary: releasing factors that trigger hormone release and inhibiting factors that suppress it. When a chemical reduces the production or release of a pituitary hormone, it’s called an inhibiting factor. Examples are somatostatin, which inhibits growth hormone release, and dopamine, which inhibits prolactin release. The other terms don’t fit as well: releasing hormones stimulate release, stimulating hormones are produced by the pituitary to act on other targets, and tropic hormones are pituitary hormones that act on other endocrine glands rather than inhibiting pituitary production.