The role and characteristics of endocrine system

The The role and characteristics of endocrine system neurohormones are released within a set of veins that connects the hypothalamus to the pituitary gland the hypophyseal-portal circulationand therefore the neurohormones reach the pituitary gland in high concentrations.

Hypogonadism Hypogonadism is a testicular disorder associated with low testosterone. Stimulates the adrenal gland to produce several related steroid hormones Luteinizing hormone LH and follicle-stimulating hormone FSH: The largest and most vital endocrine glands that will be covered in this chapter are the pituitary gland, thyroid gland, parathyroid glands, adrenal glands and the pancreas.

Thyroid hormones also help maintain normal blood pressureheart rate, digestion, muscle tone, and reproductive functions.

The release of the hormone testosterone is integral to the healthy development of male physical characteristics. Symptoms of acute pancreatitis most commonly begins with abdominal pain in the middle or upper left part of the abdomen and abdominal pain may increase after eating or lying flat the back.

This is important not only because nutrients are delivered to the gland by the blood vessels but also because the gland cells that line these vessels are able to detect serum levels of specific hormones or other substances that directly effect the synthesis and secretion of the hormone the gland produces.

Pancreatitis simply means inflammation of the pancreas. A special case is that of the pheromonea substance generated by an organism that influences, by its odour, the behaviour of another organism of the same species.

Stimulates the thyroid gland to produce thyroid hormones A lack of thyroid hormones either because of a defect in the pituitary or the thyroid itself is called hypothyroidism.

An Overview of the Testes

In addition, some organs function both as exocrine glands and as endocrine glands. The hypothalamus also secretes a hormone called somatostatin, which causes the pituitary gland to stop the release of growth hormone.

The end result of the two negative feedback loops is that, under ordinary circumstances, hormone production by target glands and the serum concentrations of target gland hormone are maintained within very narrow limits but that, under extraordinary circumstances, this tight control can be overridden by stimuli originating outside of the endocrine system.

In the pituitary gland, the target gland hormone acts to decrease the secretion of the appropriate pituitary hormone, which results in less stimulation of the target gland and a decrease in the production of hormone by the target gland. This form of control is known as paracrine control.

These hormones control the development of female characteristics for example, breast growthand they are also involved in reproductive functions for example, menstruationpregnancy.

An often-quoted example is the musky scent of the females of many species, which provokes sexual excitation in the male. Parathyroid Glands The parathyroid glands are two pairs of small glands embedded in the surface of the thyroid gland, one pair on each side.

Anatomy of the Endocrine System

The pancreas has digestive and hormonal functions. Endocrine glands and the hormones they secrete help to regulate metabolic processes.

These nerve cells are considered true endocrine cells because they produce and secrete hormones that enter the circulation to reach their target cells. Most hormones are one of two types: Exocrine glands secrete another category of substances. The traditional core of an endocrine system consists of an endocrine gland, the hormone it secretes, a responding tissue containing a specific receptor to which the hormone binds, and an action that results after the hormone binds to its receptor, termed the postreceptor response.

The simplest level of control over endocrine gland secretion resides at the endocrine gland itself. It may even result in the secretion of another hormone.

Hormones and the Endocrine System

The inner part, or adrenal medulla, produces hormones called catecholamines for example, adrenaline. They help to regulate water balance, electrolyte balance, and blood pressure.

Luteinizing hormone LH stimulates testosterone production. Neurotransmittersa group of chemical compounds of variable compositionare secreted at all synapses junctions between nerve cells over which nervous impulses must travel. Hypothalamus The hypothalamus is located in the lower central part of the brain.

Primary refers to a defect with the testicles, and secondary involves a problem in the pituitary gland that indirectly affects testosterone production.

While simple direct hormonal effects on human behaviour are difficult to document because of the complexities of human motivation, there are many convincing demonstrations of hormone-mediated behaviour in other life-forms. Prostaglandins mediate important biological effects in almost every organ system of the body.

The hypothalamus sends a signal to the pituitary gland to release gonadotrophic substances follicle stimulating hormone and luteinizing hormone. Growth hormone deficiency in adults results in problems in maintaining proper amounts of body fat and muscle and bone mass.

Hormones act on their target tissues by binding to and activating specific molecules called receptors. Growth factors are substances that stimulate the growth of specific tissues. Some endocrine glands, such as the thyroid gland and the islets of Langerhans in the pancreasare derived from cells that arise in the embryonic digestive system.

Anatomy of the Testes The testes are twin oval-shaped organs about the size of a large grape. Maintaining libido Maintaining muscle strength and mass Promoting healthy bone density The hypothalamus and pituitary gland control how much testosterone the testes produce and secrete. National Library of Medicine Each endocrine gland also has a rich supply of blood vessels.

They release parathyroid hormone, which plays a role in regulating calcium levels in the blood and bone metabolism. This response mechanism involves the interruption of the primary feedback loop to allow the serum concentrations of hormones to be increased or decreased in response to environmental stresses that activate the nervous system.Hormones and the Endocrine System.

See related health and response to injury, stress, and environmental factors. Consider the following hormones and their role in the workings of the endocrine system: Where the hormone is produced. Hormone(s) secreted. Hormone function Affects development of female sexual characteristics.

The endocrine system is made up of glands that produce and secrete hormones, chemical substances produced in the body that regulate the activity of cells or organs. These hormones regulate the body's growth, metabolism (the physical and chemical processes of the body), and sexual development and.

Start studying General Characteristics of the Endocrine System. Learn vocabulary, terms, and more with flashcards, games, and other study tools. General Characteristics of The Endocrine System The endocrine system is basically a group of glands called endocrine glands that secrete hormones into the internal environment of our body.

Hormones diffuse from the interstitial fluid into the bloodstream, and act on target cells. The testes are twin endocrine glands that release testosterone, a hormone necessary for the normal development of male physical characteristics, such as muscle mass and hair growth.

This article overviews testes function in the endocrine system. Function of the endocrine system The nature of endocrine regulation Endocrine gland secretion is not a haphazard process; it is subject to precise, intricate control so that its effects may be integrated with those of the nervous system and the immune system.

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The role and characteristics of endocrine system
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