The ultralong feedback mechanism is a feedback process in the human body that is particularly important for hormone balance. One such self-regulating feedback loop is, for example, the interplay between the thyroid hormone and the thyrotropin (TSH) it releases. If this feedback loop is disturbed, it results in diseases such as Graves’ disease, an autoimmune defect of the thyroid gland.
What is the ultralong feedback mechanism?
Thanks to the ultralong feedback mechanism, hormones control their own secretion. This is a physiological self-adjustment. At the center of this mechanism is the hypothalamus. It is a crucial control center of the human body and is located in the diencephalon. The hypothalamus keeps the human body temperature constant and is the organizer of all reflexes of food intake. The emotional and sexual behavior is determined as well as the waking and sleeping rhythm. With regard to hormones, the hypothalamus regulates when and in what quantity a certain substance is produced and released. For this purpose, special nerve cells of the hypothalamus are connected to the neighboring pituitary gland (hypophysis), whose hormones in turn form other hormones or directly supply the target organs of the body with them. The hypothalamus is where all feedback is bundled, which includes the ultralong feedback mechanism as well as the ultrashort feedback mechanism. The differences between these two mechanisms lie in opposing levels of feedback. The long or ultralong feedback mechanism establishes connections between the hypothalamus and the hormonal body periphery as well as information from the environment. Correspondingly, the short- or ultrashort-feedback mechanism serves the relations between the hypothalamus and the central nervous system. Information about altered hormone concentrations usually arrives in the brain from the body periphery. This data is transmitted from the hypothalamus to the pituitary gland. This pathway is again an ultrashort feedback mechanism. The response of hormone release from the pituitary gland then occurs via a long- or ultralong-feedback mechanism.
Function and task
Ultralong feedback is one of several feedback mechanisms and, for example, is also responsible for controlling the endocrine (hormone-producing) system. Thus, its functioning has a crucial effect on metabolic regulation, water and electrolyte stores, growth processes, blood pressure, and reproduction. In this way, the entire hormonal balance of the human body is divided into long and short regulatory circuits. In this way, it is possible to react to the organism’s respective hormone requirements at any given time and to organize the supply of the corresponding active substances. At the center is the axis between the hypothalamus and the pituitary gland. All hormonal information is passed on via this axis. Each regulatory or control circuit is directly connected to the other, so that the disruption of a single feedback mechanism inevitably leads to complications in the entire hormonal balance. This is then reflected in impairments of bodily functions. Examples of this are hyperthyroidism or hypothyroidism. These phenomena are usually the result of an oversupply or deficiency of the hormone thyrotropin. This in turn is due to a specific malfunction of the pituitary gland. An excess of thyrotropin can also indicate a tumor in the area of the thyroid gland. In this way, too, all hormone regulatory circuits are sensitively disturbed. Graves’ disease is also caused by specific disturbances in the regulatory circuits. In this case, there is hyperfunction of the thyroid gland, which is often associated with goiter formation in the area of the thyroid gland. The body’s immune system produces more antibodies; the signal for this comes from the disturbed regulatory circuits. The thyroid gland in turn reacts to this with increased activity and becomes larger due to the growth impulses. The long and ultra-long feedback mechanism carries these malformations to the periphery of the body and causes various possible diseases. An example of this is the so-called Cushing’s syndrome. Here, there is a massive disturbance of the hypothalamus-pituitary-adrenal cortex axis. Specifically, the blood sugar level may rise massively, which can lead to diabetes mellitus type 2.Severe joint wear and muscle weakness may also occur. Likewise, a so-called truncal obesity with the typical “bull neck” can develop from it.
Diseases and complaints
The ultralong feedback mechanism is part of the so-called thyrotropic regulatory circuit between the hypothalamus, pituitary gland and thyroid gland. This influences the level of thyroid hormones in the blood plasma. In this axis, the pituitary gland is responsible for the release of the hormone thyrotropin. Normally, there is a quantitative balance of thyroid hormone and thyrotropin. This balance is constantly controlled and, if necessary, regulated by the hypothalamus. To this end, it controls the production of both thyroid hormone and thyrotropin. The yardstick for maintaining this balance is the ultralong feedback mechanism. Its so-called autoregulation also levels the thyroid’s iodine uptake. If the iodine concentration in the blood is too low, the absorption of iodine in the gastrointestinal tract and thus in the thyroid is automatically increased. In the case of hypothyroidism or hyperthyroidism, the thyrotropic control loop is impaired in any case. This can be due to diseases of the thyroid gland itself, but also to a tumor, for example of the pituitary gland. The thyroid gland may also suffer from hormone resistance, either naturally or due to inappropriate use of medications. Even changes in the far periphery can have negative effects on thyroid function because they are inextricably linked by the ultralong feedback mechanism. In this case, harmful environmental influences, especially from allergens, as well as deficiencies in metabolic circulation due to the feedback effect in the thyrotropic control circuit, can also lead to serious diseases of the thyroid gland, requiring partial or total removal of this [[organ|organ]].
