hypothalamic-hypophyseal portal system
Pronunciation: hy-po-tha-LAM-ic hy-po-FIZ-ee-al POR-tal
Specialized vascular network that carries releasing hormones from the hypothalamus to the anterior pituitary.
Full Definition
The hypothalamic-hypophyseal portal system is a unique vascular arrangement consisting of two capillary networks connected by portal vessels. The primary capillary plexus is located in the median eminence where hypothalamic neurons release their hormones. These hormones are then carried via portal veins to the secondary capillary plexus in the anterior pituitary, where they regulate hormone secretion from specific cell types. This system allows direct hypothalamic control of anterior pituitary function.
Usage
Usage note: Portal system unique to anterior pituitary; posterior pituitary has direct neural connections.
In Context
- "Disruption of the hypothalamic-hypophyseal portal system can cause multiple pituitary hormone deficiencies." — Neurosurgery complication report
- "The hypothalamic-hypophyseal portal system was visualized using contrast-enhanced MRI." — Imaging study methodology