Page 757 - Atlas of Histology with Functional Correlations

Pars intermedia is remnant of the pouch and rudimentary in humans

Pars tuberalis surrounds the neural stalk
Neurohypophysis (posterior pituitary) consists of three parts
Median eminence is located at the base of hypothalamus
Infundibulum is the neural stalk that connects neurohypophysis to
hypothalamus

Pars nervosa is the largest portion that consists of unmyelinated axons and
pituicytes

VASCULAR AND NEURAL

CONNECTIONS OF HYPOPHYSIS

Adenohypophysis

Connection between hypothalamus of brain and adenohypophysis is vascular
Superior hypophyseal arteries form fenestrated primary capillary plexus in

median eminence
Secretory neurons in hypothalamus terminate on capillary plexus and release
hormones

Hypophyseal venules connect to secondary capillary plexus in the
adenohypophysis, forming a hypothalamohypophyseal portal system
Hypothalamus produces both releasing hormones and inhibitory hormones
for cells in adenohypophysis
Releasing or inhibitory hormones are carried via the portal system to cells in

pars distalis
Releasing hormones bind to specific receptors in cells of pars distalis

Cells and Hormones of Adenohypophysis

Based on stains, there are three cell types: acidophils, basophils, and
chromophobes
Acidophils are subdivided into somatotrophs and mammotrophs

Basophils are subdivided into thyrotrophs, gonadotrophs, and corticotrophs

Somatotrophs

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