krinein = to separate; formation of internal secretions (= hormones) with release into blood or lymph stream.

An internal gland secretion--directly into the blood stream.

relating to cells or glands which secrete a substance directly into the bloodstream. The substance is delivered by the blood to anywhere in the body it is needed.

This term applies to organs whose function is to secrete active biochemicals into the blood circulation that effects other distant organs. Usually there is a feed-back system that turns the secreting off when the desired effect has occurred.[close window