The unique structure of the human brain and its possibilities are of interest of scientists. So, a tiny division of the gray matter – the pituitary gland, weight in gram is enough – acts as the Central element of the endocrine system. Producing specific substances called «hormones of the pituitary gland» regulates growth, protein synthesis, functioning of the endocrine glands. The dimensions of this unpaired body increase during pregnancy in women not returning after giving birth to the original state.
The structure and functions of pituitary gland
The pituitary gland – an anatomical entity (body) oval shape, whose dimensions depend on individual characteristics. The average length reaches 10 mm, the width is a couple mm larger. The pituitary gland is located in saddle bags (the Turkish saddle) of the sphenoid bone of the skull. Has a small weight – from 5 to 7 mg, and in women it is more developed. Experts link the situation with the luteotropic mechanism generating prolaktinom responsible for the development of maternal instincts, the work of the mammary glands.
Fixing the connecting shell holds the body of the «Turkish saddle.» The interaction of the various parts of the brain, especially the hypothalamus, the pituitary gland is performed by means of feet in the funnel of the diaphragm. Being a single establishment, this gland is divided into:
- the anterior part, occupying up to 80% of the body;
- rear division, stimulating neurosecretory production;
- the middle part is responsible for the functions of fat burning.
What hormones produces
The pituitary gland and the hypothalamus are interrelated departments of the human brain combined in the hypothalamic-pituitary system, which is responsible for the action of endocrine mechanisms. «Hierarchy» of the last built in logic: glands and hormones of the pituitary gland interact on the principle of the inverse relationship: when suppressing the excess production of certain substances, the brain normalizes hormonal balance of the body. The shortage is compensated by injecting into the blood of the required number. That produces the pituitary gland?
The anterior pituitary
The anterior lobe of the pituitary gland has the properties to produce tropic (regulatory) hormones that consist of endocrine cells in glandular type. Coordinating the activity of peripheral glands secretion – pancreatic, thyroid, sex, adenohypophysis «acts» under the influence of the hypothalamus. From the functions of the anterior lobe depends on the growth, development, reproduction, lactation mammals.
Adrenocorticotropic substance produced by the pituitary gland, stimulates the adrenal hormones. ACTH indirectly acts as a «trigger» release into the blood of cortisol, cortisone, estrogen, progesterone, androgens. Normal levels of these hormones provides the successful counteraction of the organism to stress situations.
These substances have a close connection with the sex glands and are responsible for the mechanisms of reproductive abilities. The pituitary gland produces gonadotropic substances:
- Follikulostimulirutee, the quantity of which depends on the maturation of ovarian follicles in women. The male body is under their influence helps to develop sperm cells, regulates the healthy functioning of the prostate.
- Luteinizing: female estrogen which participated in the processes of ovulation and maturation of the corpus luteum, and male androgens.
Synthesized by the anterior lobe of the pituitary gland, thyroid stimulating substances (TSH) are coordinators of the thyroid gland in the production of thyroxine, triiodothyronine. Differing diurnal changes of indicators, these hormones affect the heart, blood vessels, mental activity. Metabolic processes is impossible without the participation of thyroid hormones.
Growth hormone (GH) stimulates the formation of protein structures in the cell, whereby the development, growth of human organs. Growth hormone acts on the anterior pituitary processes in the body indirectly through the thymus and liver. The functions of this hormone include control over the production of glucose, adherence to lipid balance.
The awakening of maternal instincts, the normalization of the processes of appearance of milk in women in the postpartum period, protection from conception during lactation is a partial list of properties characteristic synthesized by the pituitary luteotropic hormone. Prolactin is a stimulator of tissue growth, the coordinator of the metabolic functions of the body.
Located separately from the front, adherent to the posterior part of the pituitary gland, the average share is the source of the formation of two types of polypeptide hormones. They are responsible for the pigmentation of the skin, its reaction to exposure to UV radiation range. Producing melanocytestimulating substances depends on reflex influence of light on the retina.
The posterior lobe
«Taking» and accumulating hormones of the hypothalamus, neurohypophysis (posterior division) becomes a source of education:
- Of vasopressin. The most important substance that regulates the activity of the genitourinary, nervous, cardiovascular systems. This antidiuretic hormone acts on reabsorbiruetsa function of the renal tubules, holding water. The result of a deficiency of vasopressin becomes advancing dehydration, similar in symptomatology with diabetes mellitus.
- Oxytocin. Is responsible for smooth muscle contraction of the uterus during childbirth. Stimulates sexual arousal.
The connective tissue of the intermediate lobe of the pituitary gland presents the alpha and beta intermediary affecting the pigmentation of the surface layers of the epidermis, as well as corticotropin-immune peptides that are responsible for memory function. A feature of this Department is the ability to produce basophil cells, stimulates the burning of fat in the body – lipotropin.
Which pass the tests for hormones of the pituitary gland
Problems caused by impaired functioning of the pituitary gland, result in unpleasant consequences imbalances of health. The occurrence of individual symptoms is a significant reason to consult an endocrinologist. According to the results of a personal interview at the reception, discussing current complaints and the examination, the physician must order a special examination:
- In the lab:
- A blood test for hormones. By stimulating the production of certain substances, the pituitary gland of a healthy person produces such a number, which helps to maintain hormonal background in norm.
- The sample with the use of an antagonist of dopamine («the pleasure hormone») is metoclopramide. Helps to identify abnormalities in activity of the pituitary gland due to a tumor.
- At the eye doctor. Study of the fundus reflects the probability of formation of pituitary adenomas. Features locations of the body such that when the existence of the factors of compression is rapidly deteriorating vision.
- With the neurosurgeon, neurologist. The presence of headaches is one of the signs of the disorder of the functioning of the pituitary gland. In such cases, should carry out studies using MRI or CT.
The value of hormone levels
The results of the studies on hormones reflect the major changes in the hormonal balance under which the endocrinologist individually selects a map of the treatment:
- The lack of a separate appointed special hormone replacement therapy. Treatment involves intake of drugs, which are synthetic analogues of rare substances.
- The overabundance of hormones of the pituitary gland is often linked to the formation of tumors. The medication is intended to affect the reduction of pressure of the tumor.
Conservative treatment is popular but not the only method of normalization of the activity of the hypothalamic-pituitary system. The development of benign tumors in most cases occurs at a very slow pace. In cases of progression of the adenoma can be applied operative intervention, and in its malignant degeneration in radiation therapy is appointed.
That reduces the production
Causes changes in the production of hormones by the pituitary gland are:
- At high level the main factor of imbalance of metabolism performs an adenoma is a tumor with benign nature. Has a high level secreted by the pituitary gland hormones in the blood. Dangerous progressive development.
- The education deficit of the hormones produced by the pituitary gland, influenced by:
- genetic/congenital disease;
- blood flow disorders, hemorrhage;
- meningitis (encephalitis) in history;
- trauma, blows to the head.
The effects of increasing and decreasing standards
Hormones of the brain pituitary directly or indirectly affect the activity of the gonads, endocrine system, protein synthesis and melanin. Changes of the optimal ratio of these substances lead to negative consequences, as causes of diseases:
- Hypothyroidism (or hyperthyroidism) – thyroid dysfunction.
- Acromegaly (gigantism) or dwarfism.
- Of hyperprolactinemia. In men impotence causes in women – infertility.
- Gipopithuitarizme the deficit produced by the pituitary gland hormones. The consequences are delay of sexual development in adolescents.
- Diabetes insipidus. Characterized by the inability of tubules to absorb water, filtered by the renal glomeruli with the same level of glucose in the blood.
Video: diseases of the pituitary and adrenal glands
Abnormal development from birth, genetic mutations, the appearance of tumors in the brain provoke a decrease (Hypo) or increase (Hyper-) production of hormones. Genetic/hereditary features of the disease are manifested enhanced or delayed growth of body parts – gigantism, dwarfism. Crashing the production of tropic hormones of the pituitary gland cause diseases of the adrenal, thyroid, gonads. Learn how depends on the internal secretion of the body from functioning of the hypothalamic-pituitary system, looking at the video.