Releasing and inhibiting hormones Releasing and inhibiting hormones Releasing hormones and inhibiting hormones are hormones whose main purpose is to control the release of other hormones, either by stimulating or inhibiting their release. They are also called liberins () and statins () (respectively), or releasing factors and inhibiting factors. The examples are hypothalamic-pituitary hormones that can be classified from several viewpoints: they are hypothalamic hormones (originating in the hypothalamus), they are hypophysiotropic hormones (affecting the hypophysis, that is, the pituitary gland), and they are tropic hormones (having other endocrine glands as their target). For example, thyrotropin-releasing hormone (TRH) is released from the hypothalamus in
Pituitary gland of the pituitary in fish, apart from the lungfish, is generally different from that in other animals. In general, the intermediate lobe tends to be well developed, and may equal the remainder of the anterior pituitary in size. The posterior lobe typically forms a sheet of tissue at the base of the pituitary stalk, and in most cases sends irregular finger-like projection into the tissue of the anterior pituitary, which lies directly beneath it. The anterior pituitary is typically divided into two regions, a more anterior "rostral" portion and a posterior "proximal" portion, but the boundary between the two is