A gland refers to an organ that prepares and releases hormones that perform specific functions inside the body. Endocrine and exocrine glands release only the substances that are prepared inside the bloodstream. The endocrine glands are The glands that make up the endocrine system to produce chemical messengers known as the hormones that travel via the blood to various parts of the body. Major endocrine glands are like the pituitary, thyroid, parathyroid, thymus, and adrenal glands. The hypothalamus releases either hormones or electrical messages towards the pituitary gland. Instead they release hormones that carry signals to other glands. This system is able to maintain its own balance. When the hypothalamus detects the increasing level of hormones from a target organ, then it sends a message to the pituitary gland to stop the secretions of certain hormones. When the pituitary stops releasing hormones, then it leads the target organ to stop producing their hormones. The continuous adjustment of these hormone levels allows the body to function normally.
Nine different types of Endocrine Glands
Nine different types of the Endocrine System are:
There are different glands that form the endocrine system. The hypothalamus, pituitary gland, and pineal gland are the ones that are present in the brain. The thyroid and parathyroid glands are situated in the neck region. The thymus is located in between the lungs, the adrenals are situated on the top of the kidneys, and the pancreas is present behind the stomach. Lastly, the gonads are located in the pelvic region.
Hypothalamus: it is an organ that connects our endocrine system with the nervous system. Its main aim is to control the pituitary gland to start or stop making hormones.
Pituitary gland: it is also known as the endocrine system’s master gland. Pituitary gland uses the information which it receives from the brain and further controls other glands in the body about how to function. This gland prepares many important hormones, comprising growth hormone; prolactin, that is involved in helping the breastfeeding moms to make milk; antidiuretic hormone(ADH) (vasopressin), this controls blood pressure and also functions to control body water balance through its effect on the kidney, corticotropin /ACTH: adrenocorticotropic hormone- these hormones stimulates the adrenal glands to produce certain hormones, thyroid-stimulating hormone (TSH), that helps in stimulating the production and secretion of thyroid hormones, oxytocin hormone functions in ejection of milk during breastfeeding; and luteinizing hormone, manages oestrogen in women and testosterone in men.
Pineal gland: It produces a chemical known as melatonin that helps to maintain the sleep-wake cycle of the body.
Thyroid gland: This gland produces thyroid hormone that helps to control the growth and metabolism. If production in this gland is lowered (it leads to a condition known as hypothyroidism), then the process of growth and metabolism happens more slowly. It also reduces the heart rate of a person. People might get constipated. And they may gain weight. If the production is increased (leads to hyperthyroidism) the process speeds up. In such a case the heart rate accelerates. Person suffers from diarrhoea. And they tend to lose weight without trying. The thyroid gland also makes the hormone calcitonin, that contributes in bone strength and by helping calcium to get accumulated inside the bone.
Parathyroid: it is a set of four small glands situated behind the thyroid. They play a functional role in bone health. This gland helps control your levels of calcium and phosphorus.
Thymus: this gland produces white blood cells known as the T-lymphocytes that fight against infections and are important as the child’s immune system develops. The thymus begins to reduce in size after puberty.
Adrenals: they are also known as the “fight or flight” hormone adrenaline (also referred to as epinephrine), both of these glands also produce hormones known as the corticosteroids. They mainly affect the metabolism heart rate, oxygen intake, blood flow, and sexual function, among other things.
Pancreas: This organ represents a part of both our digestive and endocrine systems. It helps the digestive enzymes in the breakdown of food. It also produces the hormones insulin and glucagon. Both of these hormones ensure that a person has the right amount of sugar in a person’s bloodstream and the cells.
Gonads – The male reproductive gonads, or testes, and female reproductive gonads, or ovaries, releases steroids that generally affect the growth and development and also functions to regulate the reproductive cycles and behaviours. The main types of gonadal steroids are androgens, oestrogens, and progestin, all of which are present in both males and females but at varying levels.
Conclusion
The term “gland” does not necessarily mean that the organ is part of the endocrine system. For example, sweat glands, salivary glands, glands in mucus membranes, and mammary glands are known as exocrine glands, since they secrete substances other than hormones and they secrete the substances into ducts, instead secreting them directly into the bloodstream. Here we come to an end of this topic. We hope that you were able to get a clear concept regarding endocrine glands.