Overview of Endocrine Glands

Endocrine glands space glands that have no duct and also release their secretions directly into the intercellular liquid or right into the blood.

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Learning Objectives

Differentiate amongst the varieties of endocrine glands (pituitary , thyroid, parathyroid, adrenal, and also pancreas) in the endocrine system

Key Takeaways

Key PointsThe key endocrine glands are the pituitary (anterior and also posterior lobes), thyroid, parathyroid, adrenal (cortex and also medulla), pancreas, and also gonads.The parathyroid glands are four masses that tissue, two installed posteriorly in every lateral mass of the thyroid gland.The kidnize lies follow me the lower curvature that the stomach, near to where it meets the an initial region of the small intestine, the duodenum.Key Termsadrenal gland: This gland is responsible for releasing hormone in solution to tension through the synthesis of corticosteroids, such as cortisol and catecholamines (epinephrine (adrenaline) and norepinephrine), and the production of androgens.thyroid: one of the largest endocrine glands, it is responsible because that the cheap of thyroxine i m sorry controls how easily the body provides energy, provides proteins, and is perceptible to various other hormones.

Endocrine glands are ductless and release your secretions directly into the intercellular liquid or into the blood. A repertoire of endocrine glands makes up the endocrine system: the pituitary (anterior and also posterior lobes), thyroid, parathyroid, adrenal (cortex and also medulla), pancreas and gonads.


Endocrine glands in the person head and neck: The endocrine mechanism is the mechanism of glands, every of i beg your pardon secretes different varieties of hormones straight into the bloodstream (some that which room transported along nerve tracts) to regulate the body.

Pituitary Gland

The hypothalamus renders up the lower region of the diencephalons and also lies just above the brain stem. The pituitary gland (hypophysis) is uncovered in the inferior component of the brain, attached come the bottom that the hypothalamus by a slender stalk dubbed the infundibulum.

The pituitary gland consists of two major regions, the anterior pituitary gland (adenohypophysis) and the posterior pituitary gland (neurohypophysis). The hypothalamus additionally controls the glandular cheap of the pituitary gland.

Posterior Pituitary Gland

Communication between the hypothalamus and also the posterior pituitary occurs with neurosecretory cell that span the short distance between them. Hormones developed by the cabinet bodies of the neurosecretory cells room packaged in vesicles and transported v the axon and also stored in the axon terminals the lie in the posterior pituitary.

When the neurosecretory cells are stimulated, the activity potential generated triggers the relax of the stored hormones from the axon terminals to a capillary network within the posterior pituitary. 2 hormones—oxytocin and antidiuretic hormone (ADH)—are produced and released this way.

Anterior Pituitary Gland

The anterior pituitary is associated in sending hormones that manage all other hormones that the body. That is lobe is obtained from dental ectoderm and also is composed of glandular epithelium.

Communication between the hypothalamus and also the anterior pituitary occurs with hormones (releasing hormones and inhibiting hormones) the are developed by the hypothalamus and delivered to the anterior pituitary via a portal network that capillaries. The releasing and also inhibiting hormones are created by dedicated neurons of the hypothalamus dubbed neurosecretory cells.

These hormones space released into a capillary network that offers the anterior pituitary. The hormones then diffuse native this secondary plexus into the anterior pituitary, whereby they initiate the manufacturing of certain hormones by the anterior pituitary.

Thyroid Gland

This is one of the biggest endocrine glands in the body. That is positioned top top the neck just below the larynx and also has 2 lobes, one ~ above either side of the trachea.

It is involved in the production of the hormone T3 (triiodothyronine) and also T4 (thyroxine). This hormones rise the metabolic task of the body‘s cells.

The thyroid also produces and also releases the hormone calcitonin (thyrocalcitonin) that contributes come the regulation that blood calcium levels. Thyrocalcitonin or calcitonin to reduce the concentration that calcium in the blood, where most of the is save on computer in the bones.


There are four parathyroid glands, all situated on the thyroid gland. Among its most crucial functions is to regulate the body’s calcium and also phosphorus levels.

All four glands likewise secrete parathyroid hormone, or PTH, which reasons calcium come be released from the bones earlier into the extracellular fluid. PTH is released directly into the bloodstream and travels to its target cells, i m sorry are frequently quite much away and found in bone, kidneys, and also the cradle system.

Calcitonin, a hormone produced by the thyroid gland that likewise regulates ECF calcium levels, serves to against the calcium-producing impacts of PTH.

Adrenal Glands


Adrenal glands: These space responsible for releasing hormones in an answer to anxiety through the synthesis of corticosteroids such together cortisol, and also catecholamines such as epinephrine (adrenaline) and also norepinephrine.

The adrenal glands are a pair the ductless glands located over the kidneys. With hormonal secretions, castle regulate numerous essential bodily features including biochemical balances that affect athletic training and general stress response.

The glucocorticoids include corticosterone, cortisone, and hydrocortisone or cortisol. This hormones offer to wake up the switch of amino acids into carbohydrates, a process known as gluconeogenesis, and also the formation of glycogen by the liver. They likewise stimulate the development of reserve glycogen in the tissues, such as in the muscles.


The pancreas is a an extremely important body organ in the digestive and also the circulatory equipment that helps to keep our blood sugar levels. It is thought about to be part of the gastrointestinal system due to the fact that it produces digestive enzymes. These room released into the little intestine to help in to reduce food particles to straightforward elements that deserve to be soaked up by the intestine and also used by the body.

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It has another, very different duty in the it develops insulin, glucagon, and other hormone that space sent right into the bloodstream to control blood sugar levels and also other activities throughout the body.