Vessel
Hypophyseal portal system
Vessels carrying hypothalamic signals to the anterior pituitary
High-yield
Long portal vessels descend from the median eminence; shorter vessels connect lower stalk or posterior-lobe capillaries with the anterior lobe. Portal flow is its principal supply, but purely portal perfusion is an oversimplification of human vascular anatomy.
Overview
Two capillary networks connected by portal veins create a short vascular route from the hypothalamus to anterior pituitary cells. Factors released near the median eminence enter portal blood and reach the gland before dispersing through the general circulation.
Reference facts
- Origin
- The primary plexus receives superior hypophyseal arterial blood around the median eminence and upper infundibulum.
- Course
- Portal veins travel along the stalk into the secondary capillary network of the adenohypophysis.
- Branches
- Long and short portal vessels link different parts of the hypothalamic-pituitary vascular network.
- Supplies
- Delivers hypothalamic regulatory factors and much of the anterior pituitary's perfusion.
- Drains to
- Blood leaves the anterior pituitary through hypophyseal veins toward the cavernous sinuses.
Clinical correlation
Stalk damage can reduce anterior pituitary stimulation while raising prolactin by interrupting dopamine delivery, provided functioning lactotrophs remain. The resulting deficiencies depend on the extent and location of damage.
Frequently asked questions
Where does the hypophyseal portal system originate?
The primary plexus receives superior hypophyseal arterial blood around the median eminence and upper infundibulum.
What does the hypophyseal portal system supply?
The hypophyseal portal system supplies the delivers hypothalamic regulatory factors and much of the anterior pituitary's perfusion.
Where does blood from the hypophyseal portal system go?
The hypophyseal portal system drains to the blood leaves the anterior pituitary through hypophyseal veins toward the cavernous sinuses.
What are the branches of the hypophyseal portal system?
Branches of the hypophyseal portal system include the long and short portal vessels link different parts of the hypothalamic-pituitary vascular network.