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Adenosine: sleep propensity increases in the course of wakefulness: the longer the previous wakefulness period is, the longer and deeper (measured as delta power in EEG recordings) is the following sleep. The mechanisms that regulate the need of sleep at the cellular level are largely unknown. The inhibitory neuromodulator, adenosine, is a promising candidate for a sleep-inducing factor: its concentration is higher during wakefulness than during sleep, it accumulates in the brain during prolonged wakefulness, and local perfusions as well as systemic administration of adenosine and its agonists induce sleep and decrease wakefulness. Adenosine receptor antagonists, caffeine and theophylline, are widely used as stimulants of the central nervous system to induce vigilance and increase the time spent awake.
(www.biopsychiatry.com/adenosine.htm)
Adrenal Glands: when you think about the adrenal glands, you should think about stress. Stress can take many forms: taking an examination, recovering from a broken bone, running away from an invading army, or maintaining proper levels of energy substrates in the face of even mild starvation. The adrenal glands produce three major classes of hormones, each of which aid in dealing with the multitude of small and large stresses faced by animals and people almost daily.
(http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocrine/adrenal/)
Antidiuretic Hormone (ADH), Aldosterone, and Osmolarity: the primary effect of ADH is to limit the amount of water being lost in urine, by increasing the amount of water being reabsorbed into the blood. The ADH targets the cells of the tubules and collecting ducts, which causes an increase of permeability of the cell surfaces, where the water then leaves the renal tubules by means of osmosis. With more fluid being reabsorbed, the blood volume increases while the solutes concentration becomes more diluted. As soon as the osmolarity of the blood and body fluids is reduced, with more fluid being reabsorbed by the tubules in the kidneys, the receptors in the hypothalamus are no longer stimulated and the level of ADH stimulation is reduced, which then in turn signals to the kidneys to start excreting more water in the urine production until the blood osmolarity increases enough for the cycle to be started again. ADH is not the only hormone that helps with the regulation of kidney function - aldosterone (from the adrenal cortex) as well as parathyroid hormone (from the parathyroid glands) affects the balance and regulation of electrolyte content of the blood and body fluids. When aldosterone is present in the blood, the distal renal tubules increase their re-absorption of sodium and the secretion of potassium. With this action, more water is retained in the body and a person with high aldosterone content can have “puffy” features from the increased water volume. Aldosterone is secreted by the adrenal glands when the level of the potassium in the blood is increased, as well as the self-regulatory action of the kidneys by means of the renin-angiotensin system.
(www.anytestkits.com/kidney-functions-regulating-of-it.htm)
Cortisol: an important hormone in the body that is secreted by the adrenal glands. It is involved in the following functions and more: proper glucose metabolism, regulation of blood pressure, insulin release for blood sugar maintenance, immune function, inflammatory response. Normally, it’s present in the body at higher levels in the morning, and at its lowest at night. Although stress isn’t the only reason that cortisol is secreted into the bloodstream, it has been termed “the stress hormone” because it’s also secreted in higher levels during the body’s ‘fight or flight’ response to stress, and is responsible for several stress-related changes in the body.
(http://stress.about.com/od/stresshealth/a/cortisol.htm)
Endocrine System: the nervous system sends electrical messages to control and coordinate the body. The endocrine system has a similar job, but uses chemicals to “communicate”. These chemicals are known as hormones. A hormone is a specific messenger molecule synthesized and secreted by a group of specialized cells called an endocrine gland. These glands are ductless, which means that their secretions (hormones) are released directly into the bloodstream and travel to elsewhere in the body to target organs, upon which they act.
(http://biology.clc.uc.edu/courses/bio105/endocrin.htm)
Endorphins: neurotransmitters found in the brain that have pain-relieving properties similar to morphine. There are three major types of endorphins: beta endorpins, found primarily in the pituitary gland; and enkephalins and dynorphin, both distributed throughout the nervous system. Endorphins interact with opiate receptor neurons to reduce the intensity of pain: among individuals afflicted with chronic pain disorders, endorphins are often found in high numbers. Many painkilling drugs, such as morphine and codeine, act like endorphins and actually activate opiate receptors. Besides behaving as a pain regulator, endorphins are also thought to be connected to physiological processes including euphoric feelings, appetite modulation, and the release of sex hormones. Prolonged, continuous exercise contributes to an increased production and release of endorphins, resulting in a sense of euphoria that has been popularly labeled “runner’s high.”
(www.bartleby.com/65/en/endorphi.html)
Estrogen: a hormone that comprises a group of compounds, including estrone, estradiol and estriol. It is the main sex hormone in women and is essential to the menstrual cycle. Although estrogen exists in men as well as women, it is found in higher amounts in women, especially those capable of reproducing. Estrogen contributes to the development of secondary sex characteristics, which are the defining differences between men and women that don’t relate to the reproductive system. In women, these characteristics include breasts, a widened pelvis, and increased amounts of body fat in the buttock, thigh and hip region. Estrogen also contributes to the fact that women have less facial hair and smoother skin then men. Estrogen is manufactured mostly in the ovaries, by developing egg follicles. In addition, estrogen is produced by the corpus luteum in the ovary, as well as by the placenta. The liver, breasts and adrenal glands may also contribute to estrogen production, although in smaller quantities.
(www.wisegeek.com/what-is-estrogen.htm)
Histamine: a hormone/chemical transmitter involved in local immune responses, regulating stomach acid production and in allergic reactions as a mediator of immediate hypersensitivity. When released from mast cells, histamine causes vasodilatation and an increase in permeability of blood vessel walls. These effects, in turn cause the familiar symptoms of allergy including a runny nose and watering eyes. When released in the lungs, histamine causes the airways to swell shut in an attempt to close the door on offending allergens and keep them out. Unfortunately, the ultimate result of this response is the wheezing and difficulty in breathing seen in people with asthma- an occasionally deadly allergic complication, which kills an estimated 4000 Americans yearly.
(www.hon.ch/Library/Theme/Allergy/Glossary/histamine.html)
Hormone Replacement Therapy: a treatment for women who have reached or passed menopause, which often is referred to as "the change of life." HRT involves taking doses of one or two female hormones, estrogen and progesterone.
(www.ehealthmd.com/library/hrt/HRT_whatis.html)
Hormones: a chemical substance synthesized and released by a cell (cells) transported through the circulatory system that has a regulatory effect on other cells. Hormones are involved regulatory processes such as control of metabolism, growth, water balance etc. Hormones do not act alone but are usually regulated through other endocrine cells or the nervous and paracrine systems and vice versa.
(www.zoo.utoronto.ca/zoo344s/hormone.htm)
Pituitary: a gland that is sometimes called the "master" gland of the endocrine system, because it controls the functions of the other endocrine glands. The pituitary gland is no larger than a pea, and is located at the base of the brain. The gland is attached to the hypothalumus (a part of the brain that affects the pituitary gland) by nerve fibers. The pituitary gland itself consists of three sections: the anterior lobe, the intermediate lobe, the posterior lobe.
(www.umm.edu/endocrin/pitgland.htm)
Prednisone: a glucocorticoid. Glucocorticoids are adrenocortical steroids, both naturally occurring and synthetic, which are readily absorbed from the gastrointestinal tract. Prednisolone is a white to practically white, odorless, crystalline powder. It is very slightly soluble in water; soluble in methanol and in dioxane; sparingly soluble in acetone and in alcohol; slightly soluble in chloroform.
(www.rxlist.com/cgi/generic/prednisolone.htm)
Progesterone: one of the hormones in our bodies that stimulates and regulates various functions. Progesterone plays a role in maintaining pregnancy. The hormone is produced in the ovaries, the placenta (when a woman gets pregnant) and the adrenal glands. It helps prepare your body for conception and pregnancy and regulates the monthly menstrual cycle. It also plays a role in sexual desire.
(www.healthywomen.org/healthtopics/progesterone)
Thyroid: a small gland, normally weighing less than one ounce, located in the front of the neck. It is made up of two halves, called lobes, which lie along the windpipe (trachea) and are joined together by a narrow band of thyroid tissue, known as the isthmus. The thyroid is situated just below your "Adams apple" or larynx. During development (inside the womb) the thyroid gland originates in the back of the tongue, but it normally migrates to the front of the neck before birth. Sometimes it fails to migrate properly and is located high in the neck or even in the back of the tongue (lingual thyroid) This is very rare. At other times it may migrate too far and ends up in the chest (this is also rare). The function of the thyroid gland is to take iodine, found in many foods, and convert it into thyroid hormones: thyroxine (T4) and triiodothyronine (T3). Thyroid cells are the only cells in the body which can absorb iodine. These cells combine iodine and the amino acid tyrosine to make T3 and T4. T3 and T4 are then released into the blood stream and are transported throughout the body where they control metabolism (conversion of oxygen and calories to energy). Every cell in the body depends upon thyroid hormones for regulation of their metabolism.
(www.endocrineweb.com/thyfunction.html)
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