- The hypothalamo-pituitary axis is the connection between hypothalamus and pituitary:
- vascular with the anterior pituitary, via the portal hypophyseal vessels;
- neural with the posterior pituitary, via the hypothalamo-hypophyseal tract.
Portal Hypophyseal Vessels
- The connection between hypothalamus and anterior pituitary is vascular, via the portal hypophyseal vessels.
- These are a true portal system: blood passes from capillaries to capillaries without traversing the heart.
- Releasing hormones from the hypothalamus (hypophysiotropic hormones) reach the anterior pituitary via this hypophyseal portal circulation.
Path of the blood