Blood sugar level several interacting systems, of which hormone regulation is the most important. There are two types of mutually antagonistic metabolic hormones affecting blood glucose levels: These hormones are secreted from pancreatic islets which are bundles of endocrine tissues. There are four types of pancreatic islets, alpha (A) cells, beta (B) cells, Delta (D) cells and F cells. Glucagon is secreted from alpha cells, while insulin is secreted by beta cells. Together they regulate the blood-glucose levels through negative feedback, a process where the end product of one reaction stimulates the beginning of another reaction. In blood-glucose levels, insulin lowers the concentration
Bidder's organ Bidder's organ Bidder's organ is a spherical, brownish organ in most members of the family Bufonidae (true toads). The organ is located just in front of the kidney, or mesonephros. It is formed at the cranial tip of the male and female gonad during the larval stage. Its main function appears to be endocrine, taking part in regulating sex hormones. Normally, it contains miniature egg follicles which have the capability to mature (becoming active). Zoologists have experimented with the physiology of the organ by castrating male toads (removing the testes). In doing so, the Bidder's organ enlarges and produces viable