Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Menstrual cycle wikipedia , lookup
Xenoestrogen wikipedia , lookup
Neuroendocrine tumor wikipedia , lookup
Mammary gland wikipedia , lookup
Hyperthyroidism wikipedia , lookup
Adrenal gland wikipedia , lookup
Breast development wikipedia , lookup
Hormone replacement therapy (male-to-female) wikipedia , lookup
It is a small pea size gland situated in a hollow bony pouch, at the base of the brain, at the back of the bridge of the nose. The pituitary gland is approximately the size of a grape. It hangs by a stalk from the inferior surface of the hypothalamus of the brain. It has two functional lobes_the anterior pituitary (glandular tissue) and the posterior pituitary (nervous tissue). It is the master gland of the endocrine system and controls the functions of the other endocrine glands in the body. View that shows the pituitary gland structure . H Hoorrm moonneess ooff tthhee A Anntteerriioorr P Piittuuiittaarryy::-1) Growth hormone (GH)Muscles and bones, or somatotropin, produced by the anterior pituitary, affects the physical appearance dramatically since it determines an individual's size and height. 2) Prolactine (PRL)Mammary glands, Is producored by the anterior pituitary only after childbirth. It causes the mammary glands in the breast to develope and produce milk. 3) Follicle-stimulating hormone (FSH)Ovaries or testes, Which stimulate the gonads-the testes in males and the ovaries in females-to secrete sex hormones. 4) Luteinizing hormone (LH) Ovaries or testes, Which stimulate the gonads-the testes in males and the ovaries in females-to secrete sex hormones. 5) Thyroid-stimulating hormone (TSH)Thyroid glands, Which stimulates the thyroid to produce thyroxin. 6) Adrenocorticotropic hormone (ACTH)Adrenal cortex, Which stimulates the adrenal cortex to produce and secrete hormones. H Hoorrm moonneess ooff tthhee ppoosstteerriioorr P Piittuuiittaarryy::-*Releases hormones made by the hypothalamus. 1) OxytocinUterus and mammary glands, is another hormone made in the hypothalamus and released by the posterior pituitary. Oxytocin causes the uterus to contract and can be used to artificially induce labor. It also stimulates the release of milk form the breast when a baby is nursing. 2) Antidiuretic hormone (ADH)Kidney, also called vasopression, promotes the reabsorption of water from the kidneys, thereby preventing dehydration. The hypothalamus is believed to contain cells that are sensitive to blood solute consentrations. When these cells detect that the blood lacks sufficient water, ADH is produced by special neurosecretory cells and is transported by their fibers to the posterior pituitary, where it is released. As the blood becomes more dilute, the hormone ceases to be produced and released. View that shows anterior and posterior pituitary hormone effect . An abnormal growth of the pituitary gland is called an adenoma. It usually grows very slowly over many years. The pituitary gland sits in a very limited space and surrounded by the very important structures including blood vessels and nerves. Therefore, when an adenoma enlarges it can have a compression effect on the normal pituitary tissue which then fails to work properly. Gradually the expansion of the adenoma can press on surrounding areas causing headache and disturbed vision. Is a general metabolic hormone. It is a hormone produced by the pituitary and has effects on the various tissue of the body. In children, it is essential to reach normal growth. In adult, it is important to keep up with normal energy level and to keep body tissues (e.g. muscles, bones) healthy. Hyposecretion of GH During childhood;; leads to pituitary dwarfism Hypersecretion of GH During childhood;; leads to gigantism ** GH is produced in greatest quantities during childhood and adolescence, when most body growth is occurring, but is still produced (though lower quantities) in adults to aid in continued protein synthesis and normal cell division and replacement. If GH production increases in an adult after full height has been obtained, only the bones of the jaw, eyebrow ridges, nose, fingers, and toes respond. When these bones begin to grow, the person aquires a slightly grotesque look, with huge fingers and toes. This condition is called acromegaly. The hypothalamus, located beneath the thalamus in the lower walls and floor of the third ventricle of the brain, helps regulate the body's internal environment. For example, The hypothalamus helps control the heart rate, body temperature, and water balance, as well as the activity of the pituitary gland. The pituitary gland is small-about 1 centimeter in diameter- and lies just inferior to the hypothalamus. It has two portions: (1) the anterior pituitary, or hypothalamus, and, (2) the posterior pituitary. PPoosstteerriioorr PPiittuuiittaarryy ::-The posterior pituitary is connected to the hypothalamus by means of a stalk like structure. The hormones released by the posterior pituitary are made in nerve cell bodies in the hypothalamus. The hormones then migrate through the axons that terminate in the posterior pituitary. A Anntteerriioorr PPiittuuiittaarryy ::-The hypothalamus controls the anterior pituitary by producing hypothalamic-releasing and release-inhibiting hormones, Which are transported to the anterior pituitary by the blood within a portal system. Each of these hypothalamic hormones causes the anterior pituitary either to secrete or to stop secreting a specific hormone. The anterior pituitary produces at least six different hormones. Since these hormones have an effect on other endocrine glands, the anterior pituitary is sometimes called the master gland. View that show pituitary gland with hypothalamus . *Acromegaly is the Greek word for "extremities" and "enlargement". When the pituitary gland produces excess growth hormones, this results in excessive growth --called acromegaly. The excessive growth occurs first in the hands and feet, as soft tissue begins to swell. It most commonly affects middle-aged adults and can result in serious illness and premature death. In children the related condition is called gigantism, because long bones can still grow. The disease because of its slow and often insidious onset, is frequently not diagnosed correctly. Soft tissue swelling of the hands and feet (early sign) Brow and lower jaw protrusion (enlarging jaw and hat size). Enlarging hands (ring size). Enlarging feet (shoe size). Arthritis and carpal tunnel syndrome Teeth spacing increase. Heart failure (major medical problem). Compression of the optic chiasm leading to loss of vision in the outer visual fields Diabetes mellitus. Hypertension. Acromegaly is caused by prolonged overproduction of GH by the pituitary gland. The pituitary is a small gland at the base of the brain that produces several important hormones to control body functions such as growth and development, reproduction, and metabolism. In over 90 percent of acromegaly patients, the overproduction of GH is caused by a benign tumor of the pituitary gland, called an adenoma. These tumors produce excess GH and, as they expand, compress surrounding brain tissues, such as the optic nerves. This expansion causes the headaches and visual disturbances that are often symptoms of acromegaly. In addition, compression of the surrounding normal pituitary tissue can alter production of other hormones, leading to changes in menstruation and breast discharge in women and impotence in men. Symptoms of acromegaly vary depending on how long the patient has had the disease. The following are the most common symptoms. However, each individual may experience symptoms differently: Swelling of the hands and feet Facial features become coarse as bones grow Body hair becomes coarse as the skin thickens and/or darkens Increased perspiration accompanied with body odor Protruding jaw Voice deepening Enlarged lip, nose, and tongue Thickened ribs (creating a barrel chest) Joint pain Degenerative arthritis Enlarged heart Enlargement of other organs Strange sensations and weakness in arms and legs Snoring Fatigue and weakness Headaches Loss of vision Irregular menstrual cycles in women Breast milk production in women Impotence in men The symptoms of acromegaly may resemble other conditions or medical problems. Consult a physician for diagnosis. Patient with acromegaly—years before presentation (a) and at presentation (b) . View that shows lower jaw for patient with acromegaly . Diseased hand on the left, normal hand on the right for comparison . View for both hands R and L for a patient with acromegaly Diseased foot on the left, normal foot on the right for comparison . View for the foot for a patient with acromegaly AP and Lateral . a) Exaggerated supraorbital ridges. b) Exophthalmos. c) Enlargement of: i) Hands and Feet. ii) Mandible (separation of teeth). iii) Nose, Lips and Tongue. d) Bitemporal hemianopsia to blindness. e) Weight gain. f) Hypertension. g) Cardiomegaly. h) Hepatomegaly. i) Hypertrichosis. j) Hyperthyroidism i) Goiter. ii) Thyrotoxicosis. k) Diabetes Insipidus. Small pituitary adenomas are common. During autopsies, they are found in up to 25 percent of the U.S. population. However, these tumors rarely cause symptoms or produce excessive GH or other pituitary hormones. Scientists estimate that about 3 out of every million people develop acromegaly each year and that 40 to 60 out of every million people suffer from the disease at any time. However, because the clinical diagnosis of acromegaly often is missed, these numbers probably underestimate the frequency of the disease. Several tests are useful in diagnosing acromegaly. The most important are laboratory tests that measure the levels of GH and IGF-I in the blood. There are different ways to measure these levels accurately. You may have a series of blood tests. Or, you may have blood taken after an overnight fast and an early morning drink of a concentrated glucose solution. This is called an oral glucose tolerance test (OGTT). Other tests, such as head scans by magnetic resonance imaging (MRI) or computed tomography (CT), are designed to look for a pituitary growth or tumor, the most likely source of the excessive GH secretion. Normally, these tests are performed on an outpatient basis inside a hospital or clinic and involve no special preparation on your part. Head scans are a way to provide your health care provider with “photographs” of the inside of your head. Still other tests, such as an electrocardiogram (ECG), chest Xray, eye and visual field examination, and/or colonoscopy, will help your doctor check your overall health. These tests also usually do not require hospitalization and are performed by health care specialists in different fields. These specialists and/or technicians will send all test results directly to your health care provider. Your health care professional will then provide you with your test results, as well as specific information regarding your current levels of GH and IGF-I. You may want to understand the results of all of your tests and learn your GH and IGF-I levels so that you can become an active participant in your own treatment. *We can take two type of radiographic projection :(1) AP axial sella turcica. (2) Lateral R or L sella turcica. *The sella turcica lying in the center of the inner aspect of the base of the skull, It is a shallow depression called the Pituitary fossa and contains the pituitary gland. The anterior clinoids are on either side of the tuberculum sellae which forms anterior and upper part of the pituitary fossa. The dorsum sellae with the posterior clinoids forms its posterior boundary. The floor of the pituitary fossa appears as a white line called the lamina dura lying above the sphenoidal sinus. The location of sella turcica in the skull . *35 degree fronto-occipital view of sella turcica (pituitary fossa). It is a basic projection. Equipment required :a) 18×24 cm detail screen cassette, HD, lengthwise. b) Table bucky. c) Small foam pad. d) Small localizing cone. e) Lead protective waist apron. Patient position :- Lie the patient supine in the center of the x-ray couch. Rest the hands and arms at the side of the body. Place the back of the head in the midline in contact with the couch top or in a small foam pad if necessary. Tuck the chin well in and position the head so that the median sagittal plane and the radiographic baseline are both at right angles to the film. Immobilize the head. Place anatomical marker, collimate beam using small localizing cone and apply protection. Centering point :In the midline 7.5 cm above the nasion towards the foramen magnum . Direction of central ray Vertical with tube angled 35° towards the feet (caudal). 80 KV, 22 MAS, 100 cm F.F.D, Use grid . Special features :Expose on arrested respiration. An additional projection using a slit diaphragm or narrow collimation may be used to demonstrate the pineal gland more clearly if it appears on the initial examination. *Right lateral view of sella turcica (pituitary fossa) . It is a basic projection. Equipment required :a) 18×24 cm screens cassette, crosswise,detail. b) Table bucky. c) Sand bags. d) Foam pads. e) Small localizing cone. f) Lead protective waist apron. Patient position :- Lie the patient in the center of the x-ray couch. Turn the head to the lateral position with the side of the head in contact with the couch top in the midline. Support the raised shoulder with sandbags and pads and rest the arms in comfortable position. Adjust the head so that the median sagittal plane is parallel and the interorbital line is at right angles to the film. Immobilize the head. Place anatomical marker, collimate beam using a small localizing cone and apply protection. Centering point :2.5 cm in front of and above the external auditory meatus Direction of central ray Vertical at 90° to the film 80 kV, 10 MAS, 100 cm F.F.D, Use grid . Special features :- Expose in arrested respiration. The opposite lateral may be taken if difficulty is experienced in obtaining a satisfactory projection. The patient may also be examined in the erect position using a vertical bucky or skull unit. The goals of treatment are to reduce GH production to normal levels, to relieve the pressure that the growing pituitary tumor exerts on the surrounding brain areas, to preserve normal pituitary function, and to reverse or ameliorate the symptoms of acromegaly. Currently, treatment options include surgical removal of the tumor, drug therapy, and radiation therapy of the pituitary. a) Surgery. b) Drug therapy. c) Radiation therapy. SSuurrggeerryy:: The only way to cure pituitary acromegaly is with transsphenoidal surgery and adenoma removal. However, cure may be difficult to achieve in patients with particularly large or invasive tumors. In such instances, medical therapy and/or radiation therapy may be necessary to control GH levels. In general, the higher the pre-operative GH level, the lower the chance for cure. Longterm cure of acromegaly after transphenoidal surgery is seen in approximately 80-85% or patients with microadenomas and in approximately 50-60% of patients with macroadenomas. M Meeddiiccaall tthheerraappyy:: For patients with persistent GH elevation after surgery, octreotide or stereotactic radiosurgery or both are generally indicated. Octreotide (given three times a day by injection or by one monthly injection) achieves long-acting suppression of GH in about 70% of patients. It causes some degree of tumor shrinkage in 30-50% of patients, and often improves symptoms of soft tissue swelling, headache, joint pains and sleep apnea. The preoperative use of octreotide also may facilitate tumor removal and lessen the risks of general anesthesia. Side effects may include loose stools, malabsorption, cholelithiasis (gall stones), local pain at the injection site. Bromocriptine is a "dopamine agonist" which lowers GH secretion in about 15% of acromegalic patients. The major side effect is gastrointestinal upset. Growth hormone lowering and tumor shrinkage are seen in only 10 - 15% of patients with acromegaly. R Raaddiioo--tthheerraappyy:: For patients whose acromegaly is not controlled with surgery, both conventional (external beam) and stereotactic radiosurgery are relatively effective. However, the lowering of GH and IGF-1 levels takes significantly longer with external beam radiotherapy (average 7 years) compared to stereotactic radiotherapy (average 18 months). Also, external beam radiation reliably causes loss of normal pituitary function over 5 to 10 years. Neurologic complications such as visual loss, weakness, and memory impairment have rarely been reported with both external beam and stereotactic radiotherapy. ===================================== ============================