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Hormones of metamorphosis

Changes in our body in subsequent developmental stages happen mainly because of the hormones secreted by 3 endocrine glands: pituitary gland, testicles and ovaries. Pituitary gland produces growth hormonegrowth hormonegrowth hormone, which speeds up the digestion of spare fats and glycogen, increases the absorption of calcium and phosphates needed for building bones, and stimulates cells to multiply. Its work causes a child's silhouette to become more slender, and the body to become taller. Growth hormone deficiency in childhood, caused by decreased pituitary function, leads to dwarfism. A child suffering from this condition will be no taller than 140‑150 cm in adult years. The condition may be prevented when the patient is given growth hormone. Too much of the growth hormone, caused by the increase in pituitary gland functioning, may lead to gigantism. Kids with this problem grow faster than their peers and very often they are over 205 cm when they are adults.

Acromegaly is a hormonal disorder that develops when your pituitary gland produces too much growth hormone during adulthood. When this happens, bones increase in size, including those of hands, feet and face. If excess growth hormone is produced during childhood the result is gigantism.

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Ilustracja przedstawia porównanie proporcji sylwetki ludzkiej pod wpływem hormonu wzrostu. Na osi X stoją cztery szare postacie mężczyzn. Na osi Y zaznaczono podziałkę wzrostu w centymetrach. Pierwsza postać jest niska. Za mała ilość hormonu wzrostu w dzieciństwie spowodowała karłowatość przysadkowatą. Drugi od lewej to mężczyzna o prawidłowym wzroście. Ilość hormonu w okresie wzrostu była odpowiednia. Trzeci mężczyzna, najwyższy z nich, poddany został w dzieciństwie działaniu za dużej ilości hormonu wzrostu. Cierpi na gigantyzm. U ostatniej z sylwetek wystąpiła akromegalia, gdy u osób dorosłych po zakończeniu wzrostu jest zbyt duża ilość hormonu wzrostu.

Growth hormone, together with sex hormones produced by gonads – testosteronetestosteronetestosterone (produced mainly in testicles) and estrogensestrogensestrogens (produced mainly in ovaries) contributes to our body’s development in puberty. Gonads stay dormant until we enter puberty, when their secretion increases. Higher levels of sex hormones causes the development of sex organs and shapes the characteristic silhouette of our body.

Hormones that control metabolism

ThyroxinethyroxineThyroxine secreted by the thyroid has partial influence on our development and growth. It speeds up metabolism, increases the pace of burning fat in tissues, raises sugar level in blood and body temperature. Thyroxine deficiency can lead to suppression of growth and mental development, low metabolism, whereas too much of thyroxine leads to weakening of the body, heart problems, nervousness, increased appetite and hot flashes.

InsulininsulinInsulin and glucagonglucagonglucagon are responsible for processes of transforming sugars. The hormones work in an antagonistic way and are secreted by the cells of the pancreas. They maintain correct level of glucose in our blood, which should be around 70‑110 mg in 100 ml of blood on an empty stomach. Insulin lowers the sugar level in blood, whereas glucagon is responsible for raising it. The amount of insulin depends on the level of glucose – the higher the level, the more insulin is produced. Lack of insulin leads to diabetesdiabetesdiabetes. This disease can damage the kidneys, cardiovascular system and even cause sight loss. Treatment of diabetes is based on a special diet focused on regular meals, limiting sweets and using insulin and other drugs that lower the level of blood in the body.

Hormone of fight and flight

AdrenalineadrenalineAdrenaline is one of the hormones produced by adrenal glands. It is usually produced in small amounts. Its amount increases very quickly when we are stressed and when there are factors that disturb the homestasis of our organism. For example, in life threatening situations, this hormone initiates a number of processes that mobilize the organism and that allow us to fight or flight. Under the influence of adrenaline, the amount of blood that reaches the heart, muscles, brain and skin is increased. At the same time, the blood vessel of the abdomen become narrower, e.g. the vessels that are around the intestine. This limits digestion. Because of adrenaline, the frequency and strength of heart contractions is increased, same with blood pressure. We take quicker breaths, glucose level in blood increases. Muscle cells receive a lot of fuel and oxygen, thanks to which they are able to make a lot of effort, in extreme situations this effort is described as superhuman.

The influence of medicine and hormones on our body

Lowered amount of hormones in blood may cause various diseases. In order to alleviate the results of decreased amount of hormones or force a gland to work, we use hormone‑based drugs. E.g. in order to restore the homestasis in our body caused by decreased functioning of the ovaries and estrogen deficiency during menopause, the hormone replacement therapy is used. This means that the patients receive physiological amounts of estrogen in order to replenish its deficiency.

Some hormones have strong anti‑inflammatory and stimulating properties. Cortisol is given in acute allergic reactions, whereas adrenaline – in heart problems. Hormonal medicine used in motor system diseases are anabolic steroid, e.g. testosterone used as a medicine that stimulates muscular development. Taking hormonal medicine is connected with serious side effects, which is why the medicine should be taken under doctor’s supervision.

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Schemat przedstawia typowe objawy wybrane konsekwencje przyjmowania testosteronu. W centrum schematu napis: Some effects of taking testosterone without a doctor’s supervision. Wymienione efekty: increased blood pressure, infertility, heart attack, baldness-acne, trouble with erection, mood swings.

Summary

• Correct development of the body depends on hormone levels.

• Adrenaline is responsible for initiating processes that mobilize the organism, either to fight or to flight.

• Insulin and glucagon work antagonistically, regulating the sugar level in the blood.

Keywords

homeostasis, insulin, glucagon

Glossary