Hypothalamus and pituitary Hormone

Pituitary gland is one of the most important intrathoracic tubules located beneath the brain and connected to the third ventricle of the brain. This small gland causes a lot of vital activity in our body. The pituitary consists of the two lobes (posterior) and the anterior (former) lobes, which are itself under the influence of the hypothalamus.

Posterior part

This part of the building has no glands, but part of the nervous system that is made up of axons. The cellular bodies of these axons are in the hypothalamus of the brain. Antidiabetic hormones and oxytocin are made in the cellular body of the hypothalamic neurons and transmitted through the axons to the posterior posterior pituitary and stored along with the neurofazin I and II proteins.

Vasopressin or antidepressant hormone (ADH)

The hormone is a peptide that stimulates water reabsorption from kidney tubes and urinary retention in the kidney. This hormone together with neurophysin II is stored in the later part of the pituitary. Lack of it leads to insipid diabetes.

Oxytocin hormone

The hormone is a peptide that causes smooth uterine muscle contraction (ease of delivery) and milk ducts (lung eruption). This hormone is reserved for neurofazine I in the later part. There are oxytocin receptors in the uterus and mammary glands. Progesterone inhibits oxytocin secretion.

Hypothalamus and pituitary hormone

Hypothalamus and pituitary hormone

Anterior part

This part forms the largest part of the adenohypophysis. The secreted hormones are called Stimulating Hormones. And are influenced by hypothalamic-release hormones. These hormones include growth hormone (GH), thyroid stimulating hormone (TSH), luteinizing hormone (LH), follicular stimulatory hormones (FSH), adrenocorticotropin hormone (ACTH) and prolactin (prolactin).

Human Growth Hormone, Somatrophic Hormone

The hormone is secreted by the cells of the previous pituitary and plays an important role in regulating growth. Growth hormone plays an important role in the body’s anabolism by increasing protein synthesis, increasing fatty acid decomposition in adipose tissue and increasing blood glucose levels. This hormone also increases the absorption of calcium, magnesium and phosphate in the body, leading to bone growth along the length and diameter of the bones.

Decreasing the growth hormone in adults causes metabolic dysfunction with increased body fat, reduced muscle mass, decreased muscle strength, reduced bone density, dynamic dysregulation of lipoprotein and carbohydrates, and altered kidney and heart function. Growth hormone releasing hormone (GRH), secreted from the hypothalamus, stimulates the release of this hormone from pituitary gland.

Clinical application:

  1. Acromegaly diagnosis and gigantism and monitoring of treatment effect (in relation to glucose suppression test)
  2. Detection of human growth hormone deficiency (in conjunction with the growth hormone stimulation test)
  3. Examining pituitary function (low and high) and monitoring the amount of growth hormone to effect treatmentExamining pituitary function (low and high) and monitoring the amount of growth hormone to effect treatment
  • Stress, physical or mental stress, exercise, food, and low blood glucose levels increase the amount of GH.
  • The amount of growth hormone increases in gigantism, acromegaly, anorexia nervosa, stress, extensive surgery, hypoglycemia, fasting, deep sleep, and exercise.
  • GH levels decrease in pituitary failure, nanism, hyperglycemia, obesity and latent sexual maturation.

Natural values:

Gentlemen: <5 ng / ml

Women: <10 ng / ml

Children: 10-0 ng / ml


Prolactin is a hormone secreted from earlier pituitary cells and has a structure similar to that of a growth hormone. The main task of prolactin is to stimulate the development of breast and to start and continue lactation.

The main inhibitor of GH is dopamine, which inhibits the secretion of this hormone from the pituitary. In humans, the levels of this hormone increase naturally during sleep, stress, exercise, sexual proximity, hypoglycemia as well as pregnancy, lactation and postpartum.

Increasing prolactin in women is usually associated with decreased libido, disorder, or menstruation, breast infections, and infertility, and in men, loss of sexual desire, breast enlargement, hypogonadism, and infertility.

  • Stress caused by bruising, trauma, surgery, or fear of blood tests and stimulation of the nipple leads to mild prolactin elevation.
  • Hook effect may be observed in rare cases of high levels of prolactin, which results in false negative results.
  • Excessive levels of prolactin may be due to the presence of macroprolactin (prolactin bound to immunoglobulin).

Natural values:

Mature men: 20-0 ng / ml

Mature Women: 25-0 ng / ml

Pregnant women: 400-20 ng / ml

  • Sampling should be done fast.
  • This test should be done at least 2 hours after waking up. Samples that are earlier than this time will show a false increase.
  • In the night before the experiment, wear plain and comfortable clothes and avoid wearing tight clothing, especially in the breast and breast.
  • It is recommended that 12 hours before the addition of nutritional supplements and biotin-containing multivitamins should not be used.


ACTH hormone secretes from the previous pituitary and increases the cortisol and aldosterone secretion from the cortical part of the adrenal gland. Cortisol is an important glucocorticoid that plays a key role in the metabolism of glucose and the body’s response to stress.Cortisol is a hormone that coordinates the functioning of the hypothalamus, pituitary, and superficial kidney. In this way, reducing cortisol levels secretes CRH from the hypothalamus and CRH, increases the secretion of the adrenocorticotropin hormone (ACTH) from the pituitary.

Measuring the amount of ACTH in the study of increasing or decreasing blood cortisol and assessing the hormonal impairment caused by impaired adrenal or pituitary function is helpful.

  • The results of measuring cortisol levels at 8:00 am and 4:00 pm often indicate that it is one third to two thirds of the morning at 4:00 pm.
  • It is best to sample the morning (8 to 6 in the morning after a comfortable night’s sleep).
  • Cortisol has a ratio of photos with ACTH levels, so that reducing cortisol, increasing ACTH, and increasing ACTH can reduce cortisol levels.
  • Typically, if the level of ACTH in an adrenal insufficiency, normal or low, is the most common cause of hypothyroidism or hypothalamic activity.
  • Increasing the production of ACTH in Addison’s disease represents an initial disorder of the adrenal gland.
  • Addison’s disease (primary failure of the adrenal gland), adenogenital syndrome (congenital adrenal hyperplasia), Cushing’s disease
  • Stress (trauma, febrile agents, hypoglycemia), monthly bleeding and pregnancy can increase ACTH and cortisol levels.
  • Exogenous corticosteroids (such as cortisone, prednisone, dexamethasone), estrogen and spirolactone reduce the level of ACTH.

Natural values:

In the morning sample: <80 pico grams per ml

In the afternoon sample: <50 pico grams per ml


The thyroid stimulating hormone (TSH) is a hormone released from the anterior part of the pituitary gland. This hormone increases the thyroid hormones secretion and increases the level of thyroid hormones by lowering the blood levels of thyroid hormones. Measuring the blood level of this hormone is very useful in treating hypothyroidism or hyperthyroidism, and it is a selective test for neonatal hypothyroidism screening.

The thyroid hormone plays a central role in controlling thyroid function and is the most useful physiological indicator of thyroid hormone activity. The main factor is determining the adjustment point in the thyroid hormones axis of the TSH.

The secretion of this hormone is regulated by the hypothalamic TRH hormone. TRH is the major stimulant for the synthesis and secretion of TSH. Approximately 15 minutes after administration of TRH, the amount of TSH secretion reaches its maximum. Reducing the levels of thyroid hormones increases TSH production and exacerbates the TRH stimulation effect on TSH. Increasing levels of thyroid hormones also rapidly and directly inhibit TSH and inhibit the TRH stimulating effect on TSH.

  • TSH, like other pituitary hormones, is secreted in rash and its secretion varies overnight at different times.
  • The level of TSH is fluctuating around the clock, with a minimum level of secretion at 10 o’clock in the morning and a maximum level of secretion of the hormone at 10 o’clock.

Increased TSH

Primary hypothyroidism


Thyroid agenesis

Congenital Curtinism

High doses of iodine

Radioactive iodine injection

Thyroid withdrawal with surgery

Severe and chronic illnesses

Reduced TSH

Secondary hypothyroidism


Suppressive doses of thyroid drugs

Artificial hyperthyroidism (thyroid medication arbitrarily inhibits TSH production)

Toxic goiter

Graves disease

Follicular stimulatory hormones (FSH) and Lotropin (LH)
FSH and LH are FSH and LH, which are glycogenic hormones that are secreted and bleeding in the early stages of the pituitary. The gonadotrophin releasing hormone (GnRH), released from the hypothalamus, regulates these hormones through the post-rolling mechanism.

FSH in women causes follicular growth of the ovary and stimulates estrogen secretion, and in men it stimulates the development of testicular sertoli cells. LH in women stimulates the release of estrogen from the follicle, ovulation, the formation of yellow corpuscles, and the release of estrogen and progesterone from it.

The level of these hormones varies in women during menstrual cycles and is secreted at different times. The maximum amount of FSH in the cycle is for the formation of the oocyte follicles, and at the same time, the LH reaches peak levels to stimulate ovulation, which results in the formation of a yellowish body that, if fertilized, can protect the fetus.

  • In women, the levels of FSH and LH vary in different stages of the menstrual cycle. So when examining the results of the test, knowing the time of the menstrual cycle is important.
  • Daily LH measurements in the time interval between women’s cycles can show the peak time of LH. It seems that the maximum fertility incidence in women occurs at this time.
  • Levels of FSH and LH in secondary failure of gonads (pituitary dysfunction or other pituitary-hypothalamic axis disorders), stress, malnutrition or physiological delay of growth and sexual differentiation are reduced.
  • Often, FSH and LH are used to diagnose menopause, initiating hormone replacement therapy

Clinical applications

Help Help with Menstrual Dysfunction
Evaluation of suspected patients with hypogonadism disorders
Predict Ovulation Time
Infertility Examination
Detection of pituitary disorders
Pre-term puberty in children




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