Anterior pituitary hormones.
<P>
   Hormone  production  in  the  anterior  pituitary (adenohypophysis) is
   controlled  by releasing and inhibiting hormones from the hypothalamus
   via portal vessels.
<P>
   Many   adenohypophysis   hormones  in  turn  have  tropic  effects  by
   regulating other hormones.
<P>
   Nontropic   hormones   act  directly  on  target  cells,  and  include
   prolactin, which stimulates milk production in the breast.