Insulin signal transduction pathway is secreted after glucose enters the beta cell and that triggers several other processes in a chain reaction. While insulin is secreted by the pancreas to lower blood glucose levels, glucagon is secreted to raise blood glucose levels. This is why glucagon has been known for decades as a counter-regulatory hormone. When blood glucose levels are low, the pancreas secretes glucagon, which in turn causes the liver to convert stored glycogen polymers into glucose monomers, which is then released into the blood. This process is called glycogenolysis. Liver cells, or hepatocytes, have glucagon receptors which allow for glucagon to attach
Pituitary gland secretes hormones. All releasing hormones (-RH) referred to, can also be referred to as releasing factors (-RF). Somatotropes: Corticotropes: Thyrotropes: Gonadotropes: Lactotropes: These hormones are released from the anterior pituitary under the influence of the hypothalamus. Hypothalamic hormones are secreted to the anterior lobe by way of a special capillary system, called the hypothalamic-hypophysial portal system. There is also a non-endocrine cell population called folliculostellate cells. The intermediate lobe synthesizes and secretes the following important endocrine hormone: The posterior pituitary stores and secretes (but does not synthesize) the following important endocrine hormones: Magnocellular neurons: Hormones secreted from the pituitary gland