Diseases of the urinary system
Pancreas reflex The pancreas a narrow 6-inch long gland on the left side of the stomach is in the posterior and inferior abdominal cavity area. This rare condition sometimes called gigantism is usually caused by a pituitary tumor and can be treated by removing the tumor. Retrieved from " https: Minimizing stress may require a team approach; we can acknowledge its importance and leave the details to the experts. The views and nutritional advice expressed by Global Healing Center are not intended to be a substitute for conventional medical service. Over time, such arterial constriction and high blood pressure can lead to vessel damage and plaque buildup—the perfect scenario for a heart attack. The activity of the pineal gland is inhibited by stimulation from the photoreceptors of the retina.
There are several different types of hormones that vary in their chemical organization and functions. The majority of hormones are peptides. These consist of short sequences of amino acids ; examples include insulin and growth hormone. The class of hormones called steroids are synthesized from cholesterol—examples include male sex steroids such as testosterone and female sex steroids such as estrogen and progesterone.
Hormone production by an endocrine organ is regulated by complex interactions, called feedback loops, between the endocrine organ and its target organs. Feedback loops are two-way modes of communication in which a target organ also releases molecules that regulate the endocrine organ.
Feedback loops are designed to maintain hormone concentration within a normal range. Endocrine disorders in which hormone concentration becomes abnormal can be difficult to diagnose and treat because of the complexity of feedback loops. One simple way to classify endocrine disorders is based on whether a condition is due to excess production hypersecretion or underproduction hyposecretion of hormone.
Located at the base of the brain, the pituitary gland produces many hormones that regulate other organs. Because of this, the pituitary is often referred to as the "master" endocrine gland, although the term "central" endocrine gland is more correct because hormone release by the pituitary is primarily regulated by a brain structure called the hypothalamus, which acts to connect the nervous system to the endocrine system.
The hypothalamus produces hormones that stimulate or inhibit the release of pituitary hormones. The hypothalamus also produces antidiuretic hormone, which regulates water balance in the body by inhibiting urine formation by the A frontal-view scintigram of a normal human thyroid. Part of the endocrine system, the thyroid controls basal metabolic rate.
Hormones released by the pituitary include growth hormone, which increases during childhood and stimulates the growth of muscle, bone, and other tissues. Sporadic bursts in growth hormone release often result in rapid growth "spurts" associated with adolescence. Hyposecretion of growth hormone can result in dwarfism, whereas hypersecretion of growth hormone can cause gigantism and other disorders.
The pituitary also produces follicle-stimulating hormone and luteinizing hormone, which stimulate gamete production and sex steroid production in male and female reproductive organs, and prolactin, which stimulates milk formation in the mammary glands.
Located adjacent to the larynx , the thyroid gland primarily produces thyroxine and triiodothyronine, collectively referred to as thyroid hormone. Thyroid hormone stimulates growth of muscles and bones, carbohydrate metabolism, and basal metabolic rate.
Its production requires iodine; the lack of dietary iodine causes goiter, a thyroid gland that is overly enlarged in an effort to compensate for the thyroid hormone deficiency.
Effects of thyroid disorders in children and adults can differ widely. For example, hyposecretion of thyroid hormone in infants causes congenital hypothyroidism, a disease characterized by mental retardation and poor body growth; hyposecretion in adults produces myxedema, with symptoms such as lethargy , weight gain, and dry skin.
Conversely, hypersecretion of thyroid hormone in adults causes Graves' disease, a condition characterized by weight loss, nervousness, and dramatic increases in body metabolism. The thyroid also produces calcitonin, a hormone that regulates blood calcium concentration.
The adrenal glands are small organs on the apex of each kidney. The outer layers of cells in the adrenal gland, called the adrenal cortex, produce several hormones that affect reproductive development; mineral balance; fat, protein, and carbohydrate balance; and adaptation to stress. The inner part, called the adrenal medulla, secretes epinephrine and norepinephrine, which activate the sympathetic nervous system and stimulate the "fight-or-flight" response that helps the body cope with stressful situations, such as fear.
The pancreas produces insulin and glucagon, which function in opposing fashion to regulate blood sugar glucose concentration. When blood glucose level rises—for example, after eating a sugar-rich meal—insulin lowers it by stimulating glucose storage in liver and muscle cells as long chains of glucose called glycogen. Conversely, between meals, blood glucose level decreases. Verbal memory scores are frequently used as one measure of higher level cognition. These scores vary in direct proportion to estrogen levels throughout the menstrual cycle, pregnancy, and menopause.
Furthermore, estrogens when administered shortly after natural or surgical menopause prevents decreases in verbal memory. In contrast, estrogens have little effect on verbal memory if first administered years after menopause. The protective effects of estrogens on cognition may be mediated by estrogens anti-inflammatory effects in the brain. Sudden estrogen withdrawal, fluctuating estrogen, and periods of sustained low estrogen levels correlate with significant mood lowering.
Compulsions in male lab mice, such as those in obsessive-compulsive disorder OCD , may be caused by low estrogen levels. When estrogen levels were raised through the increased activity of the enzyme aromatase in male lab mice, OCD rituals were dramatically decreased. Hypothalamic protein levels in the gene COMT are enhanced by increasing estrogen levels which are believed to return mice that displayed OCD rituals to normal activity.
Aromatase deficiency is ultimately suspected which is involved in the synthesis of estrogen in humans and has therapeutic implications in humans having obsessive-compulsive disorder. Local application of estrogen in the rat hippocampus has been shown to inhibit the re-uptake of serotonin. Contrarily, local application of estrogen has been shown to block the ability of fluvoxamine to slow serotonin clearance, suggesting that the same pathways which are involved in SSRI efficacy may also be affected by components of local estrogen signaling pathways.
Studies have also found that fathers had lower levels of cortisol and testosterone but higher levels of estrogen estradiol compared to non-fathers. Estrogen may play a role in suppressing binge eating.
Hormone replacement therapy using estrogen may be a possible treatment for binge eating behaviors in females. Estrogen replacement has been shown to suppress binge eating behaviors in female mice. Women exhibiting binge eating behaviors are found to have increased brain uptake of neuron 5-HT, and therefore less of the neurotransmitter serotonin in the cerebrospinal fluid. It is also suggested that there is an interaction between hormone levels and eating at different points in the female menstrual cycle.
Research has predicted increased emotional eating during hormonal flux, which is characterized by high progesterone and estradiol levels that occur during the mid- luteal phase. It is hypothesized that these changes occur due to brain changes across the menstrual cycle that are likely a genomic effect of hormones. These effects produce menstrual cycle changes, which result in hormone release leading to behavioral changes, notably binge and emotional eating.
These occur especially prominently among women who are genetically vulnerable to binge eating phenotypes. Binge eating is associated with decreased estradiol and increased progesterone. Dysregulated eating is more strongly associated with such ovarian hormones in women with BEs than in women without BEs. The associations between binge eating, menstrual-cycle phase and ovarian hormones correlated. In rodents, estrogens which are locally aromatized from androgens in the brain play an important role in psychosexual differentiation, for example, by masculinizing territorial behavior;  the same is not true in humans.
Estrogens are responsible for both the pubertal growth spurt, which causes an acceleration in linear growth, and epiphyseal closure , which limits height and limb length, in both females and males. In addition, estrogens are responsible for bone maturation and maintenance of bone mineral density throughout life. Due to hypoestrogenism, the risk of osteoporosis increases during menopause. Women suffer less from heart disease due to vasculo-protective action of estrogen which helps in preventing atherosclerosis.
Estrogen has anti-inflammatory properties and helps in mobilization of polymorphonuclear white blood cells or neutrophils. Estrogens are implicated in various estrogen-dependent conditions , such as ER-positive breast cancer , as well as a number of genetic conditions involving estrogen signaling or metabolism, such as estrogen insensitivity syndrome , aromatase deficiency , and aromatase excess syndrome.
Estrogens, in females, are produced primarily by the ovaries , and during pregnancy, the placenta. Some estrogens are also produced in smaller amounts by other tissues such as the liver , pancreas , bone , adrenal glands , skin , brain , adipose tissue ,  and the breasts.
These tissues are not able to synthesize C19 steroids, and therefore depend on C19 supplies from other tissues  and the level of aromatase. In females, synthesis of estrogens starts in theca interna cells in the ovary, by the synthesis of androstenedione from cholesterol. Androstenedione is a substance of weak androgenic activity which serves predominantly as a precursor for more potent androgens such as testosterone as well as estrogen.
This compound crosses the basal membrane into the surrounding granulosa cells, where it is converted either immediately into estrone, or into testosterone and then estradiol in an additional step.
Hence, both granulosa and theca cells are essential for the production of estrogen in the ovaries. Estrogen levels vary through the menstrual cycle , with levels highest near the end of the follicular phase just before ovulation.
These reactions occur primarily in the liver , but also in other tissues. Estrogens are excreted primarily by the kidneys as conjugates via the urine. Estrogens are used as medications , mainly in hormonal contraception and hormone replacement therapy. The estrogen steroid hormones are estrane steroids. In , Adolf Butenandt and Edward Adelbert Doisy independently isolated and purified estrone, the first estrogen to be discovered.
Shortly following their discovery, estrogens, both natural and synthetic, were introduced for medical use.
Examples include estriol glucuronide Emmenin , Progynon , estradiol benzoate , conjugated estrogens Premarin , diethylstilbestrol , and ethinylestradiol. The word estrogen derives from Ancient Greek. It is derived from "oestros  " a periodic state of sexual activity in female mammals , and genos generating. Nevertheless, both estrogen and oestrogen are used nowadays, yet some still wish to maintain its original spelling as it reflects the origin of the word.
A range of synthetic and natural substances that possess estrogenic activity have been identified in the environment and are referred to xenoestrogens. Estrogens are among the wide range of endocrine-disrupting compounds EDCs because they have high estrogenic potency. When an EDC makes its way into the environment, it may cause male reproductive dysfunction to wildlife.
Some hair shampoos on the market include estrogens and placental extracts; others contain phytoestrogens. In , there were case reports of four prepubescent African-American girls developing breasts after exposure to these shampoos. An accompanying proposed rule deals with cosmetics, concluding that any use of natural estrogens in a cosmetic product makes the product an unapproved new drug and that any cosmetic using the term "hormone" in the text of its labeling or in its ingredient statement makes an implied drug claim, subjecting such a product to regulatory action.
In addition to being considered misbranded drugs, products claiming to contain placental extract may also be deemed to be misbranded cosmetics if the extract has been prepared from placentas from which the hormones and other biologically active substances have been removed and the extracted substance consists principally of protein. The FDA recommends that this substance be identified by a name other than "placental extract" and describing its composition more accurately because consumers associate the name "placental extract" with a therapeutic use of some biological activity.
From Wikipedia, the free encyclopedia. This article is about estrogens as hormones. For their use as medications, see Estrogen medication. Estradiol , the major estrogen sex hormone in humans and a widely used medication. Sexual motivation and hormones. Estrogen metabolism in humans   . Structures of major endogenous estrogens. Cellular and Molecular Life Sciences. Molecular and Cellular Endocrinology.
Journal of Physiology and Pharmacology. A G protein-coupled receptor for estrogen". Journal of the Society for Gynecologic Investigation. Genetic Testing and Molecular Biomarkers. Estrogen's Emerging Manly Alter Ego". Retrieved 4 March Molecular and Cellular Neurosciences.
American Journal of Physiology. Lung Cellular and Molecular Physiology. The Journal of Neuroscience.