primary capillary plexus

The upper hypophyseal arteries form the primary capillary plexus that supplies blood to the median eminence.

CRH is produced by parvocellular neuroendocrine cells within the paraventricular nucleus of the hypothalamus and is released at the median eminence from neurosecretory terminals of these neurons into the primary capillary plexus of the hypothalamo-hypophyseal portal system.

The axons of the parvocellular neurosecretory neurons of the PVN project to the median eminence, a neurohemal organ at the base of the brain, where their neurosecretory nerve terminals release their hormones at the primary capillary plexus of the hypophyseal portal system.