Term
| 1 Hormones: Adrenocorticotropin (ACTH) 1 |
|
Definition
| "ACTH stimulates the production of cortisol by the adrenal glands. Cortisol, a so-called "stress hormone" is vital to our survival. It helps to maintain blood pressure and blood glucose levels." |
|
|
Term
| 1 Hormones: Antidiuretic hormone (ADH) 1 |
|
Definition
| ADH, also called vasopressin, "regulates water balance. If this hormone is not released properly, it can lead to too little hormone (called diabetes insipidus), or too much hormone (called syndrome of inappropriate ADH). Both of these conditions affect the kidneys. Diabetes insipidus is different from the more well-known diabetes mellitus (or type II diabetes), which affects the levels of glucose in our bodies." |
|
|
Term
| 1 Hormones: Follicle-stimulating hormone (FSH) 1 |
|
Definition
| "FSH promotes sperm production in men and stimulates the ovaries to enable ovulation in women. Luteinizing hormone and follicle-stimulating hormone work together to cause normal function of the ovaries and testes." |
|
|
Term
| 1 Hormones: Growth Hormone 1 |
|
Definition
| "GH stimulates growth in childhood and is important for maintaining a healthy body composition and well-being in adults. In adults it is important for maintaining muscle mass as well as bone mass. It also affects fat distribution in the body." |
|
|
Term
| 1 Hormones: Luteinizing hormone (LH) 1 |
|
Definition
| LH regulates testosterone in men and estrogen in women. |
|
|
Term
|
Definition
| "Prolactin stimulates milk production from the breasts after childbirth to enable nursing." It also affects sex hormone levels from ovaries in women and from testes in men. |
|
|
Term
| 1 Hormones: Thyroid-stimulating hormone 1 |
|
Definition
| "TSH stimulates the thyroid gland, which regulates the body's metabolism, energy, growth, and nervous system activity. This hormone is also vital to our survival" |
|
|
Term
| 1 Pituitary Gland Overview 1 |
|
Definition
| The pituitary gland is a tiny organ, the size of a pea, found at the base of the brain. As the master gland of the body, it produces and secretes many hormones that travel throughout the body, directing certain processes stimulating other glands to produce different types of hormones. The pituitary gland controls biochemical processes important to our well-being. |
|
|
Term
|
Definition
| The most frequent cause of pituitary disorders is pituitary gland tumors. "The pituitary gland is made of several cell types. Sometimes these cells grow too much or produce small growths." |
|
|
Term
|
Definition
| "These growths are called pituitary tumors, and they are fairly common in adults. These are not brain tumors and are not a form of cancer. In fact, cancerous tumors of this sort are extremely rare. Pituitary tumors, however, can interfere with the normal formation and release of hormones." |
|
|
Term
|
Definition
| Two types of tumors exist - secretory and non-secretory. "Secretory tumors produce too much of a hormone, creating an imbalance of proper hormones in the body. Non-secretory tumors cause problems because of their large size or because they interfere with normal function of the pituitary gland." |
|
|
Term
| 1 Pituitary Tumors: Causes 1 |
|
Definition
| Hypersecretion: Too much of any hormone secreted into the body is usually caused by a secretory pituitary gland tumor. Many secretory tumors make too much prolactin, the hormone that triggers milk production in new mothers. Other tumors may affect the adrenal glands, making too much of the hormones that stimulate them and causing a hormone imbalance. Tumors also can make excess growth hormone or too much of the hormone that stimulates the thyroid gland leading to overproduction of thyroid hormones. |
|
|
Term
| 1 Pituitary Tumors: Causes 1 |
|
Definition
| Hyposecretion: Too little of any hormone secreted into the body is usually caused by a non-secretory pituitary gland tumor, which interferes with the ability of the normal pituitary gland to create hormones. It can, however, also be caused by a large secretory tumor. Hyposecretion can also happen with surgery or the radiation of a pituitary gland tumor. |
|
|
Term
| 1 Pituitary Tumors: Causes 1 |
|
Definition
| 5.Tumor mass effects - As a pituitary gland tumor grows and presses against the normal pituitary gland or other areas in the brain, it may cause headaches, vision problems, or other health effects related to hyposecretion. Tumor mass effects can be seen in any type of pituitary tumor that grows large enough. Injuries, certain medications, and other conditions can also affect the pituitary gland. Loss of normal pituitary function also has been reported after major head trauma. |
|
|
Term
|
Definition
| The anterior pituitary synthesizes and secretes important endocrine hormones, such as ACTH, TSH, PRL, GH, endorphins, FSH, and LH. These hormones are released from the anterior pituitary under the influence of the hypothalamus. Hypothalamic hormones are secreted to the anterior lobe by way of a special capillary system, called the hypothalamic-hypophyseal portal system. |
|
|
Term
|
Definition
| "The anterior pituitary is divided into anatomical regions known as the pars tuberalis, pars intermedia, and pars distalis. It develops from a depression in the dorsal wall of the pharynx (stomodial part) known as Rathke's pouch." |
|
|
Term
|
Definition
| It is sometimes called the master gland of the body because all the other endocrine glands depend on its secretions for stimulation |
|
|
Term
| 2 Pituitary Gland Overview 2 |
|
Definition
| "In vertebrate anatomy the pituitary gland, or hypophysis, is an endocrine gland about the size of a pea and weighing 0.5 g (0.02 oz.). It is a protrusion off the bottom of the hypothalamus at the base of the brain, and rests in a small, bony cavity (sella turcica) covered by a dural fold" |
|
|
Term
| 2 Pituitary Gland Overview 2 |
|
Definition
| It is considered a master gland. The pituitary gland secretes hormones regulating homeostasis, including tropic hormones that stimulate other endocrine glands. It is functionally connected to the hypothalamus by the median eminence. |
|
|
Term
|
Definition
| Located at the base of the brain, the pituitary is composed of two lobes: the anterior pituitary (adenohypophysis) and the posterior pituitary (neurohypophysis). The pituitary is functionally linked to the hypothalamus by the pituitary stalk, whereby hypothalamic releasing factors are released and, in turn, stimulate the release of pituitary hormones. Although the pituitary gland is known as the master endocrine gland, both of its lobes are under the control of the hypothalamus.If there are problems with the pituitary gland, it can cause an irregular condition know as gigantisism. |
|
|
Term
|
Definition
The posterior pituitary stores and releases:
"Antidiuretic hormone (ADH, also known as vasopressin and AVP, arginine vasopressin), the majority of which is released from the supraoptic nucleus in the hypothalamus" |
|
|
Term
|
Definition
The posterior pituitary stores and releases:
Oxytocin, most of which is released from the paraventricular nucleus in the hypothalamus |
|
|
Term
|
Definition
| The pituitary is the center of human sexuality and reproduction. Other parts of the body do most of the work but the pituitary initiates and controls the processes. |
|
|
Term
|
Definition
| The pituitary regulates mood, behavior and a startling number of mental and emotional health issues. (Bi-polarity has been linked to the pituitary gland). |
|
|
Term
|
Definition
| The pituitary regulates mood, behavior and a startling number of mental and emotional health issues. (Bi-polarity has been linked to the pituitary gland). |
|
|
Term
|
Definition
| It is located between the eyes, behind the bridge of the nose, just below the brain. The pituitary lies within a bony depression in the skull called the sella turcica , which sits below the optic chia sm , the area where nerves from the eyes (the optic nerves) cross and enter the brain. |
|
|
Term
| 3 Pituitary Gland Overview |
|
Definition
| It is often referred to as the “master” gland of the body, because it produces hormones (proteins that are released into the body that influence the function of other organs) that control several other glands throughout the body, including the thyroid gland, the adrenal glands, and the sex organs (ovaries and testicles). |
|
|
Term
| 3 Pituitary Gland Overview 3 |
|
Definition
| The pituitary gland is a small gland, approximately the size and shape of a pea. It is located between the eyes, behind the bridge of the nose, just below the brain. The pituitary lies within a bony depression in the skull called the sella turcica , which sits below the optic chia sm , the area where nerves from the eyes (the optic nerves) cross and enter the brain |
|
|
Term
| 3 Pituitary Gland Overview 3 |
|
Definition
| The pituitary gland is divided into two main portions: the larger anterior pituitary (at the front) and the smaller posterior pituitary (at the back). Each of these portions has different functions, producing different types of hormones. It is rare for tumors to develop in the posterior lobe of the pituitary gland. |
|
|
Term
| 3 Pituitary Gland Overview 3 |
|
Definition
| The pituitary itself is controlled by another gland called the hypothalamus , which sits just above the pituitary gland. In response to various signals from the body, the hypothalamus sends hormones directly down a channel to the pituitary gland, telling the pituitary to produce and release its hormones into the bloodstream so they can act on various organs throughout the body. |
|
|
Term
|
Definition
| In response to various signals from the body, the hypothalamus sends hormones directly down a channel to the pituitary gland, telling the pituitary to produce and release its hormones into the bloodstream so they can act on various organs throughout the body. |
|
|
Term
|
Definition
| The pituitary itself is controlled by another gland called the hypothalamus , which sits just above the pituitary gland. |
|
|
Term
| 4 Disorders: Empty Sella Syndrome |
|
Definition
| "the sella is the structure that surrounds the pituitary gland; it may increase in size and put pressure on the pituitary; rarely, the pituitary gland shrinks in response and hormone production decreases, leading to hypopituitarism." |
|
|
Term
| 4 Disorders: Growth Hormone Deficiency 4 |
|
Definition
| from a variety of causes; in children it causes delayed growth and short stature; in adults it can lead to muscular weakness, fatigue, decreased bone mass, and obesity. |
|
|
Term
| 4 Disorders: Hyperprolactinemia 4 |
|
Definition
| a pituitary tumor that secretes prolactin or a tumor that prevents the regulation of prolactin production; can cause galactorrhea and amenorrhea, and in men decreased sex drive and impotence. |
|
|
Term
| 4 Disorders: Hypopituitarism 4 |
|
Definition
| "from a variety of causes including tumors, trauma, decreased pituitary blood supply, infection, sarcoidosis, an autoimmune process, radiation, surgical removal of the pituitary, or a side effect of pituitary surgery; results in a general decrease in pituitary hormone production." |
|
|
Term
| 4 Disorders: Pituitary Tumors 4 |
|
Definition
| "may be hormone-secreting or non-secreting; most are benign; may cause visual disturbances and headaches as they grow and compress surrounding tissues; often results in excessive amounts of one pituitary hormone and decreases in others." |
|
|
Term
| 4 Disorders: What can go wrong 4 |
|
Definition
| Pressure from a tumor can cause headaches, visual disturbances, loss of vision, fatigue, weakness, and seizures, as well as a host of signs and symptoms related to diminished hormone production. |
|
|
Term
| 4 Disorders: What can go wrong? 4 |
|
Definition
| The most common problem with the pituitary is the development of a tumor. While most are benign, they can produce excessive amounts of a specific pituitary hormone, crowd out the production of other hormones, and compress surrounding tissues. Blood vessels and the optic nerves are in close proximity to the pituitary gland |
|
|
Term
| 4 Disorders: What can go wrong? 4 |
|
Definition
| "Other pituitary disorders can arise from inherited genetic mutations, be congenital, be due to trauma or an impaired blood supply, due to surgical or radiation treatment of a previous pituitary disorder, due to a malignant tumor (rare), or be due to causes that are not yet well understood. The hormone deficiencies and excesses from these disorders can produce a variety of symptoms depending on which hormones and target tissues are affected." |
|
|
Term
| 4 Disorders: What can go wrong? 4 |
|
Definition
| "TSH in turn stimulates thyroid hormone production by the thyroid gland. If the thyroid gland is dysfunctional and cannot produce adequate amounts, then blood thyroid hormone levels will remain below normal even though the hypothalamus and pituitary are promoting production. The result is excessive amounts of TSH and deficient thyroid hormone concentrations." |
|
|
Term
| 4 Disorders: what can go wrong? 4 |
|
Definition
| "When the hypothalamus is dysfunctional, pituitary hormone production is often affected. Excess or deficient hormone production by the pituitary may also occur if the glands “downstream” from it are dysfunctional. For example, normally the hypothalamus detects thyroid hormone deficiency in the blood and stimulates the pituitary to produce TSH." |
|
|
Term
| 4 Rare Disorders: Acromegaly and Gigantism 4 |
|
Definition
| "excess growth hormone production, usually due to a tumor; when it occurs in childhood, it causes gigantism associated with excessive bone growth and abnormally tall stature; in adults, it causes acromegaly, with increases in bone thickness, coarsened facial features, enlarged hands and feet, carpal tunnel syndrome, headaches, sweating, sleep apnea, fatigue, and hypertension." |
|
|
Term
| 4 Rare Disorders: Craniopharyngioma 4 |
|
Definition
| the most common tumor that develops close to the pituitary gland in children; benign but may put pressure on the pituitary, causing hypopituitarism, headaches, visual disturbances, and delayed growth. |
|
|
Term
| 4 Rare Disorders: Diabetes Insipidus 4 |
|
Definition
| "decreased production of ADH by the hypothalamus; patient’s kidneys don’t conserve water and concentrate urine; patient is thirsty and has frequent, dilute urination." |
|
|
Term
| 4 Rare Disorders: Kallman’s Syndrome 4 |
|
Definition
| deficient release of GnRH (gonadotropin-releasing hormone) leads to lack of FSH and LH production; causes delayed or absent puberty; associated with no sense of smell; occurs only in males. |
|
|
Term
| 4 Rare Disorders: Nelson’s Syndrome 4 |
|
Definition
| "may result when both adrenal glands are removed as part of the treatment for Cushing’s Disease; a pituitary tumor develops that produces ACTH and can cause darkening of the skin due to increased production of melanocyte stimulating hormone (MSH)." |
|
|
Term
| 4 Rare Disorders: Pituitary Infarction 4 |
|
Definition
| restricted blood supply to the pituitary gland; may cause gland tissue damage and lead to hypopituitarism. |
|
|
Term
| 4 Rare Disorders: Sheehan’s Syndrome 4 |
|
Definition
| "the pituitary gland increases in size during pregnancy; can cause pituitary infarction when there is an acute drop in blood pressure." |
|
|
Term
| 4 Rare Disorders:Multiple Endocrine Neoplasia 4 |
|
Definition
| "an inherited genetic mutation that increases the risk of developing tumors in the pituitary and in other endocrine glands." |
|
|
Term
| 4 Rare disorders: Cushing’s Disease 4 |
|
Definition
| Cushing’s syndrome symptoms caused by a pituitary tumor that produces excess ACTH and leads to excess exposure to the adrenal gland hormone cortisol; symptoms vary but include: upper body obesity, a rounded face, thin skin, pink streaks on the abdomen, muscular weakness, osteoporosis, high blood sugar, and high blood pressure. |
|
|
Term
|
Definition
| The endocrine system is an integrated system of small organs that involve the release of extracellular signaling molecules known as hormones. |
|
|
Term
|
Definition
| "The endocrine system is instrumental in regulating metabolism, growth, development and puberty, tissue function, and also plays a part in determining mood." |
|
|
Term
|
Definition
| "The field of medicine that deals with disorders of endocrine glands is endocrinology, a branch of the wider field of internal medicine." |
|
|
Term
|
Definition
| "Endocrine glands regulate your body chemistry by releasing hormones directly in to the blood system, which stimulate or inhibit activity in the target cells. They are like remote-control devices for your body's many cells and systems" |
|
|
Term
|
Definition
| " It would be far too complicated to communicate with each cell in the body directly, so instead the brain controls similar types of cells using hormones released in to the blood stream." |
|
|
Term
|
Definition
| "To give you an example of how this works, imagine your sudden rise in heart rate when danger threatens or an emergency situation arises - this is caused by another 'remote control' hormone: adrenaline. This hormone, released by the adrenal gland on top of your kidney, has a very immediate and noticeable effect on your body. The hormones released from the pituitary gland are way less dramatic and not nearly as instantaneous, but work in a similar fashion and are critical to your overall health and well-being." |
|
|
Term
|
Definition
| The pituitary gland is sometimes called the "master" gland of the endocrine system, because it controls the functions of all the other endocrine glands. This "Master Gland" role makes the pituitary gland quite important, despite its small size. |
|
|
Term
|
Definition
| The medical term is hypophysis (from the Greek, "lying under") which refers to the gland's position on the underside of the brain |
|
|
Term
|
Definition
| The term "pituitary" is in reference to secretion, but has come to be synonymous with, and easier to say, than "hypophysis". |
|
|
Term
|
Definition
| The hypothalamus is the bottom part of the brain that connects and communicates with the pituitary gland via nerve fibers. |
|
|
Term
|
Definition
| "This area of the brain functions as the main control center for the autonomic nervous system by regulating sleep cycles, body temperature, appetite, etc., and that acts as an endocrine gland by producing hormones, including the releasing factors that control the hormonal secretions of the pituitary gland." |
|
|
Term
|
Definition
| "Concentrated chemical substances, or hormones, which control 10 to 12 functions in the body, have been obtained as extracts from the anterior pituitary glands of cattle, sheep, and swine." |
|
|
Term
|
Definition
| Eight hormones have been isolated, purified, and identified; all of them are peptides, that is, they are composed of amino acids. |
|
|
Term
|
Definition
| "Growth hormone (GH), or the somatotropic hormone (STH), is essential for normal skeletal growth and is neutralized during adolescence by the gonadal sex hormones. " |
|
|
Term
|
Definition
| "The two gonadotropic hormones are follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Follicle-stimulating hormone stimulates the formation of the Graafian follicle in the female ovary and the development of spermatozoa in the male. The luteinizing hormone stimulates the formation of ovarian hormones after ovulation and initiates lactation in the female; in the male, it stimulates the tissues of the testes to elaborate testosterone. In 1975 scientists identified the pituitary peptide endorphin, which acts in experimental animals as a natural pain reliever in times of stress." |
|
|
Term
|
Definition
| "Endorphin and ACTH are made as parts of a single large protein, which subsequently splits. This may be the body's mechanism for coordinating the physiological activities of two stress-induced hormones. The same large prohormone that contains ACTH and endorphin also contains short peptides called melanocyte-stimulating hormones. These substances are analogous to the hormone that regulates pigmentation in fish and amphibians, but in humans they have no known function." |
|
|
Term
|
Definition
| "Research has shown that the hormonal activity of the anterior lobe is controlled by chemical messengers sent from the hypothalamus through tiny blood vessels to the anterior lobe." |
|
|
Term
|
Definition
| In lower vertebrates this part of the pituitary secretes melanocyte-stimulating hormone, which brings about skin-color changes. In humans, it is present only for a short time early in life and during pregnancy, and is not known to have any function. |
|
|
Term
|
Definition
| "Two hormones are secreted by the posterior lobe. One of these is the antidiuretic hormone (ADH), vasopressin. Vasopressin stimulates the kidney tubules to absorb water from the filtered plasma that passes through the kidneys and thus controls the amount of urine secreted by the kidneys. The other posterior pituitary hormone is oxytocin, which causes the contraction of the smooth muscles in the uterus, intestines, and blood arterioles." |
|
|
Term
|
Definition
| "Oxytocin stimulates the contractions of the uterine muscles during the final stage of pregnancy to stimulate the expulsion of the fetus, and it also stimulates the ejection, or let-down, of milk from the mammary gland following pregnancy." |
|
|
Term
|
Definition
| "Pituitary functioning may be disturbed by such conditions as tumors, blood poisoning, blood clots, and certain infectious diseases." |
|
|
Term
|
Definition
| Conditions resulting from a decrease in anterior-lobe secretion include dwarfism, acromicria, Simmonds's disease, and Fröhlich's syndrome. |
|
|
Term
|
Definition
| "Dwarfism occurs when anterior pituitary deficiencies occur during childhood; acromicria, in which the bones of the extremities are small and delicate, results when the deficiency occurs after puberty" |
|
|
Term
|
Definition
| "Simmonds's disease, which is caused by extensive damage to the anterior pituitary, is characterized by premature aging, loss of hair and teeth, anemia, and emaciation; it can be fatal." |
|
|
Term
|
Definition
| "Oversecretion of one of the anterior pituitary hormones, somatotropin, results in a progressive chronic disease called acromegaly, which is characterized by enlargement of some parts of the body. Posterior-lobe deficiency results in diabetes insipidus." |
|
|
