A summary of the various endocrine organs, their hormones, and their functions is given in Table 1 in "The Hypothalamus and Pituitary Glands." Also listed are some organs whose major function is not the secretion of hormones, but which, nonetheless, contain some specialized cells that produce hormones. These organs include the heart, the gastrointestinal tract, the placenta, the kidneys, and the skin.
In addition, all cells (except red blood cells) secrete a class of hormones called eicosanoids.
These hormones are paracrines,
or local hormones, that primarily affect neighboring cells. Two groups of eicosanoids, the prostaglandins (PGs) and the leukotrienes (LTs), have a wide range of varying effects that depend on the nature of the target cell. Eicosanoid activity, for example, may impact blood pressure, blood clotting, immune and inflammatory responses, reproductive processes, and the contraction of smooth muscles.