Final answer:
The hypothalamic-pituitary portal system transports blood and neurohormones between the hypothalamus and the anterior pituitary without returning to the heart.
Step-by-step explanation:
The hypothalamic-pituitary portal system is a specialized vascular structure that connects the hypothalamus with the anterior pituitary. This portal system comprises a network of blood vessels that transport neurohormones directly from the hypothalamus to the anterior pituitary, allowing the hypothalamus to regulate the secretion of hormones by the anterior pituitary. It is important to note that this system does not involve transport of blood to the heart before reaching the anterior pituitary. Unlike the anterior pituitary, the posterior pituitary does not receive hormones through this portal system; instead, it stores hormones produced by the hypothalamus and releases them into the bloodstream in response to neural signals.
The correct answer to the student's question is, therefore, that the hypothalamic-pituitary portal system transports blood and neurohormones between the hypothalamus and the anterior pituitary. This transport is essential for the regulation of many physiological processes, including growth, metabolism, and stress responses.