Endocrine gland
Definition
noun, plural: endocrine glands
Any of the ductless glands secreting hormones that are released directly into the circulation and influence metabolism and other bodily functions
Supplement
The endocrine system is one of the biological systems of humans and other vertebrates. It is comprised of the endocrine glands.
The endocrine glands are ductless glands that release secretions (hormones). They do not require ducts to reach and influence target cells. The endocrine glands release hormones into the blood or lymph to reach and act on specific cells of organs. These glands aid in controlling the bodily metabolic activity, as well as serve as chemical messengers that allow cells to communicate with one another. Nevertheless, the endocrine glands are not the only tissues that secrete hormones. Autocrines (tissues that secrete chemical messengers that act on the cell that secretes them) and paracrines (tissues that secrete chemical messengers that act on nearby cells) are not considered endocrine glands. Hormones released by endocrine glands into the circulation and act on distant cells employ a form of chemical signaling referred to as endocrine signaling.
The major human endocrine glands include:
• hypothalamus
• pituitary gland
• thyroid gland
• pancreas
• adrenal glands
• pineal gland
• gonads
• ovaries
• testes
• parathyroid gland
The endocrine glands may be contrasted to the exocrine glands that also secrete hormones. However, the exocrine glands (e.g. salivary gland, sweat, gland, etc.) make use of ducts. The liver and the pancreas are considered both an endocrine gland and an exocrine gland. Some of the substances are released through ducts and others are released into the bloodstream.
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Principles of Hormonal Control Systems
Hormones are essential in the regulation of the activity of the various biological systems of the human body. The inefficiency of any of these hormonal control systems may lead to the improper functioning of the body. In this tutorial, get to know the different classes of hormones, metabolism, mechanism, and control of hormone secretions. ..
Hormone Production
Hormones are chemical messengers produced by specialized glands and they were produced by switching on the genes designed to produce them. This tutorial looks at how genes control the production of hormones within the endocrine system of animals.
Animal Growth Hormones
Hormones are produced in the endocrine glands of animals. The pituitary gland and hypothalamus are the most important in regards to the regulation of growth and development. Know the different hormones of animals in this tutorial.
Movement of Molecules Across Cell Membranes
Molecules move within the cell or from one cell to another through different strategies. Transport may be in the form of simple diffusion, facilitated diffusion, active transport, osmosis, endocytosis, exocytosis, epithelial transport, or glandular secretion. This tutorial provides elaborate details on each of these mechanisms. Find out how. ..
Control of Growth & Development
Control of Growth & Development tutorials look at how the genetic makeup determines the biological processes on a day to day basis. Various hormones are also described. Animals and plants produce hormones to incite and regulate their growth. However, growth is not only genetic and hormonal in nature. It may also depend on external factors.
Digestion and Absorption of Food
The gastrointestinal system breaks down particles of ingested food into molecular forms by enzymes through digestion and then transferred to the internal environment by absorption. Find out more about these processes carried out by the gastrointestinal system through this tutorial.