Pituitary gland

The pituitary gland is an organ or a gland that is located under the brain. In the picture above, it is the little red spot behind the eye sockets. The pituitary gland has the size of a pea. However small, it is often called the most important gland of our body.

The pituitary gland plays a vital role as a link between the nervous system and the endocrine system.

It is therefore understandable that damage to this organ may have direct consequences for the functions of other parts of the body.

Three lobes

The pituitary gland is divided into three lobes.

• the anterior lobe (pars anterior or adenohypophysis)
• posterior lobe (pars posterior or neurohypophysis)
  
• the middle lobe (pars intermedia)

Production of hormones

The pituitary gland produces a total of nine different hormones and also controls other glands in the body to produce hormones. These hormones travel through the bloodstream and are important for regulating various functions.

For example, these include growth hormones, sex hormones (for reproduction), thyroid hormones, stress hormones, hormones that regulate fluid balance (such as the ratio between drinking and urination), and hormones involved in metabolism, i.e., the conversion of food into energy.
In addition, the pituitary gland is responsible for regulating body temperature, blood pressure, and pain management, among other things.
When an elevated level of a particular hormone is detected in the blood, the pituitary gland automatically inhibits its production. Blood tests can help to better understand hormonal abnormalities and associated symptoms.

Hormones produced in the pituitary gland

• Adrenocorticotropic hormone (ACTH), also known as corticotropin
  
• Sex-stimulating hormones:
  • Luteinizing hormone LH. In women, it triggers ovulation and stimulates the production of female sex hormones, estrogen and progesterone, in the ovaries, thus contributing to menstruation and female fertility. In men, it promotes the production of testosterone.
  • Follicle-stimulating hormone: FSH. In women, it stimulates the ovaries to produce estrogen and progesterone. FSH also promotes egg maturation. In men, FSH stimulates the production and maturation of sperm.
  • Prolactin, PR. This is an hormone that stimulates breast milk production.
• Thyroid-stimulating hormone: TSH
• Growth hormone: GH
• Antidiuretic hormone: ADH or vasopressin. It regulates water and salt balance.
• Melanocyte-stimulating hormone: MSH or melanotropin. It stimulates the production of melanin = skin pigmentation/skin color and hair color and acts as an appetite suppressant in the hypothalamus.
• Oxytocin

The pituitary gland works closely together with the hypothalamus. After a stressful event, the hypothalamus produces a substance called corticotropin-releasing hormone (CRH). This hormone causes the anterior pituitary gland to produce another hormone: adrenocorticotropic hormone (ACTH), also known as corticotropin.
This substance then causes the adrenal glands to produce glucocorticoids, such as cortisol. Cortisol is an important stress hormone. If cortisol blood levels are too high or too low,
it can have many adverse health consequences for the brain, heart, and blood vessels, among other things.

PITUITARY GLAND

• Thyroid hormone TSH
• Growth hormone GH
• Adrenal cortex-stimulating hormone (ADEH), adenocorticotropic hormone (ACTH), stimulates the adrenal glands to produce cortisol.
• LH, the sex hormone, triggers ovulation, progesterone, and estrogen in women. In men, it promotes testosterone production. Follicle-stimulating hormone (FSH) promotes egg cell production in women and stimulates the ovaries to produce progesterone and estrogen; in men, it promotes sperm production and maturation.
• Antidiuretic hormone (ADH) promotes urinary retention, vasopressin.
• Melanocyte-stimulating hormone (MSH) promotes the production and release of melanin and works in the hypothalamus to suppress appetite.
• Prolactin (PR) promotes breast milk production.
• Oxytocin (cuddle hormone, bonding hormone) promotes uterine muscle contraction, important during labor, and stimulates mammary gland contraction.

In short:

Regulates hormone production.

Production of Endorphins

The pituitary gland produces three types of endorphins: α-, β-, and γ-endorphin.

Endorphins function as neurotransmitters and, among other things, as pain suppressants.

β-endorphins regulate sensory input, fine motor skills, thermoregulation, the regulation of consciousness and breathing, stress and emotions, and much more.

It is therefore understandable that damage to this organ has direct consequences for functions elsewhere in the body.

The most common problem with the pituitary gland occurs when a benign tumor develops (often referred to as an adenoma or craniopharyngioma).
Malignant tumors may also occur, but are rarer.

Injuries due to a pituitary infarction, pituitary inflammation, or traumatic brain injury to the pituitary gland are also rare.

Possible complaints due to damage to the pituitary gland

The following symptoms may be noticeable: (not in everyone, every person is different, every injury is different. Read more about lists of symptoms...)

• More emotional behavior
  

• Irritable behavior (short fuse)
  

• Mood swings
  

• Depressive moods, depression
  

• Decreased sexual desire

• Concentration problems
  

• Overstimulation, increased sensitivity to external stimuli, with the overstimulation being amplified by hormonal imbalance
  

• Memory problems
  

• Physical problems such as:
  • Extreme fatigue
    
  • Muscle fatigue
    
  • Diabetes mellitus
    
  • Diabetes insipidus: lack of or insensitivity to antidiuretic hormone due to hormonal imbalance in the brain. The hormone regulates the amount of urine excreted (diuresis).
    
  • Acromegaly, excessive growth hormone production. It causes disproportionate growth of limbs or body parts. It is called gigantism when it occurs in young people.

  • Cushing's Syndrome

    This condition involves excessive production of the adrenocorticotropic hormone ACTH, which causes the adrenal cortex to produce too much cortisol. This results in excessive cortisol levels (the stress hormone), which ultimately break down connective tissue. It can lead to muscle loss and diabetes, as well as improper fat metabolism and weight gain. It can also lead to increased urination because the other hormone, ADH (antidiuretic hormone), is inhibited. Cushing's syndrome may cause increased intracranial pressure, also known as IIH or benign intracranial hypertension. Th disease was previously called pseudotumor cerebri. It is caused by the effects of excess cortisol in the body. Many people with Cushing's become overweight, especially around the abdomen and chest. This extra fat may slow blood flow from the brain, causing increased pressure in the head. Cortisol can also affect blood vessels and blood flow, further increasing that pressure. Fortunately, this elevated blood pressure is usually reversible if the excess cortisol is treated.

     

  • Addison's disease is a condition caused by the adrenal cortex not producing enough hormones (cortisol and aldosterone) due to insufficient pituitary gland stimulation. An Addisonian crisis (due to a dangerous deficiency of the stress hormone) can put the body in a life-threatening situation.

  • Dehydration due to a deficiency of ADH /antidiuretic hormone

  • Prolactinoma is a benign tumor in the pituitary gland with excessive production of the hormone prolactin, which can cause breast milk secretion, absent menstruation in women, and low testosterone levels in men. The tumor may press on the optic nerve, causing visual disturbances and headaches.
    
  • Changes in menstruation and fertility in women: Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) together stimulate the production of the female sex hormones estrogen and progesterone in the ovaries.
  • The level of sex hormones in the body changes after a head injury. For example, women often temporarily stop menstruating after a concussion.
    
  • Menstruation may become irregular or absent due to a brain injury and a person may enter menopause and / or develop osteoporosis. See also the page on hormonal changes due to brain injury and the page on post-concussion syndrome.
  • Non-Functioning Pituitary Adenoma is a benign pituitary tumor that does not produce excess hormones. It is characterized by growth, which can compress the healthy pituitary gland and the optic nerve. Reduced control of other glands results in a hormone deficiency.
    
  • Craniopharyngioma, a benign but rare pituitary tumor. The symptoms are the same as those of a non-functioning pituitary adenoma.
    
  • Kallmann syndrome, a congenital hereditary condition that can cause a person to lose their sense of smell and delay puberty. In Kallmann syndrome, the connection between the hypothalamus and the pituitary gland is absent. As a result, the body does not produce sex hormones. It is most common in males.
    
  • Sheehan syndrome, if the mother loses a lot of blood during childbirth, the pituitary gland may be damaged or even largely die, resulting in the need for hormone replacement therapy.
  • Secondary adrenal insufficiency, when the pituitary gland functions less effectively, this may disrupt the production of adrenal hormones.
    
  • A Rathke's cleft cyst is a rare, usually benign, vesicle in the pituitary gland. See the bottom of this page for more information.

Tumor in the pituitary gland (adenoma or craniofaryngeoma)

Symptoms of a craniofaryngeoom may include: headache, blurred vision, double vision, sometimes visual impairment or blindness, (pressure on the optic nerves) to a hormonal deficiency, abnormal fatigue, poor recovery from fatigue, depression, emotional responding, reacting irritable, joint problems, Lack of puberty, weight problems, eating disorders, problems with fat metabolism and heart function. 

Also, tumors in the vicinity of the pituitary gland may put pressure onto the pituitary and thereby distort the function. Apart from the brain tumor, the cavities may be flared in that the cerebrospinal fluid can hardly be discharged.

If a tumor presses on the optic nerves (optic chiasm), it may lead to visual field loss (hemianopia).

Surgery (a transsphenoidal neurosurgical procedure) for a rare tumor, the Pituitary Neuroendocrine Tumor (PitNET), may also damage one of the cranial nerves and cause gaze palsy.

This makes it impossible for a person to look at something with both eyes simultaneously.

If a tumor presses on the hypothalamus, it may cause hypothalamic syndrome. Depending on which area of ​​the hypothalamus is affected, this can lead to eating disorders, sleep disturbances, problems with fluid balance, temperature regulation, and sexual function.

More information about the pituitary gland: http://www.pituitary.org.uk/information/what-is-the-pituitary-gland/

The pituitary foundation  

Read more about the hypothalamus

The image below explained:
The pink part in the image is the pituitary gland.
The light pink part is the anterior pituitary gland.
The dark pink part is the posterior pituitary gland.

source: https://commons.wikimedia.org/w/index.php?curid=295401

Rathke's cleft Cyst

A Rathke's cleft cyst is a rare, usually benign vesicle in the pituitary gland. 

This cyst develops from remnants of tissue from embryonic development and is often discovered incidentally during a brain scan.

A Rathke's cleft cyst usually does not cause any symptoms. However, if the cyst grows larger, it can cause headaches, hormonal problems, or vision problems because the cyst presses on surrounding tissue.
Treatment is often not necessary, but sometimes the cyst must be surgically removed.

Overview of the functions of the pituitary and hypothalamus side by side:

More information:

https://www.pituitary.org.uk/

https://pituitary.org/

https://courses.lumenlearning.com/suny-ap2/chapter/the-pituitary-gland-and-hypothalamus/

https://www.pavlatou.gr/en/hypothalamus-pituitary-gland/

https://courses.lumenlearning.com/suny-ap2/chapter/the-pituitary-gland-and-hypothalamus/