What structure connects the hypothalamus to the anterior pituitary?

• A. Infundibulum
• B. Optic nerve
• C. Corpus callosum
• D. Pineal stalk

Answer: (A)

Connecting the hypothalamus to the anterior pituitary relies on the hypothalamic-hypophyseal portal system that runs through the infundibulum, also known as the pituitary stalk. Hypothalamic neurons release releasing and inhibitory hormones into a primary capillary network in the hypothalamus; these hormones travel through portal vessels in the infundibulum to a secondary capillary plexus in the anterior pituitary, where they regulate the release of hormones like ACTH, TSH, GH, prolactin, and FSH/LH. This portal arrangement lets the hypothalamus exert precise control over the anterior pituitary with minimal dilution. The other structures don’t serve this regulatory connection: the optic nerve handles vision, the corpus callosum links the cerebral hemispheres, and the pineal stalk connects the pineal gland but doesn’t regulate anterior pituitary hormone release.