Endocrinology Health Guide The endocrine system is a complex collection of hormone-producing glands that control basic body functions such as metabolism, growth and sexual development. The amount of hormones produced by each gland is carefully balanced. Too much or too little of a certain hormone can have effects throughout the body and cause various endocrine disorders. Many of the hormones produced by the endocrine glands interact with each other to maintain balance. The endocrine system consists of: pituitary gland - secretes hormones to stimulate the adrenals, thyroid, pigment-producing skin cells and gonads (ovaries and testes). Also secretes a growth hormone, an antidiuretic hormone, prolactin (a hormone which affects milk production after childbirth) and oxytocin (a hormone which plays a role in childbirth). hypothalamus - secretes hormones that stimulate or suppress the release of hormones in the pituitary gland. pancreas - secretes insulin and glucagon, which affect the body's absorption of glucose, the body's main source of energy. adrenal cortex - secretes hydrocortisone, which affects metabolism. Also secretes androgen hormone and aldosterone, which affect blood pressure and saline balance. thyroid gland - secretes thyroxin, triiodothyronine and calcitonin, which affect metabolism, body heat, and bone growth. parathyroid glands - secretes a parathyroid hormone, which affects calcium levels in the blood. gonads - the male and female reproductive glands (testes and ovaries). The testes secrete testosterone, which stimulate sperm production and other male characteristics. The ovaries secrete estrogen and progesterone, which affect many aspects of the female body, including menstrual cycles and pregnancy. The exocrine glands actually secrete their substances through ducts to particular areas. Examples of exocrine glands include the salivary glands and the sweat glands. The endocrine glands, on the other hand, secrete the hormones they produce directly into the bloodstream. Most endocrine glands are controlled by trophic (stimulating) hormones secreted by the pituitary gland. The pituitary gland, in turn, is controlled by hormones secreted by the hypothalamus in the brain. Acromegaly What is acromegaly? 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. Acromegaly affects mostly middle-aged adults. Untreated, the disease can lead to severe illness and death. What are the symptoms of acromegaly? 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. How is acromegaly diagnosed? Due to the subtlety of the symptoms, acromegaly is often not diagnosed until years later. In addition to a complete medical history and medical examination, diagnostic procedures for acromegaly may include: serial photos taken over the years to observe physical changes in the patient x-rays to detect bone thickening blood tests to check the growth hormone level Treatment for acromegaly: Treatment of acromegaly depends on the cause of the disease. Ninety percent of acromegaly cases are caused by benign tumors on the pituitary gland. Because the tumor is compressing the pituitary gland, the hormone production can be altered. Some other acromegaly cases are caused by tumors of the pancreas, lungs, or adrenal glands. The goal of treatment is to restore the pituitary gland to normal function, producing normal levels of growth hormone. Specific treatment for acromegaly will be determined by your physician based on: your overall health and medical history extent of the disease your tolerance for specific medications, procedures, or therapies expectations for the course of the disease your opinion or preference Treatment may include removal of the tumor, radiation therapy, and injection of a growth hormone blocking drug. Left untreated, acromegaly can lead to diabetes mellitus and hypertension. The disease also increases a patient's risk for cardiovascular disease and colon polyps that may lead to cancer. Diabetes Insipidus FACT: Though produced by the hypothalamus, the portion of the brain that stimulates the pituitary gland, the antidiuretic hormone, is actually stored and released into the blo ction of the antidiuretic hormone by the hypothalamus, the portion of the brain that stimulates the pituitary gland. Normally, the antidiuretic hormone controls the kidneys' output of urine. Diabetes insipidus causes excessive thirst and excessive production of very diluted urine. Causes of diabetes insipidus: Diabetes insipidus can be caused by several conditions, including: malfunctioning hypothalamus malfunctioning pituitary gland damage to hypothalamus or pituitary gland during surgery brain injury tumor tuberculosis blockage in the arteries leading to the brain encephalitis meningitis sarcoidosis (a rare inflammation of the lymph nodes and other tissues throughout the body) What are the symptoms of diabetes insipidus? The following are the most common symptoms. However, each individual may experience symptoms differently: excessive thirst excessive urine production dehydration The symptoms of diabetes insipidus may resemble other conditions or medical problems. Consult a physician for diagnosis. How is diabetes insipidus diagnosed? In addition to a complete medical history and medical examination, diagnostic procedures for diabetes insipidus may include: urine tests blood tests water deprivation test (to observe if dehydration occurs) Treatment of diabetes insipidus: Treating diabetes insipidus depends on what is causing the disease. Treating the cause usually treats the diabetes insipidus. Specific treatment for diabetes insipidus will be determined by your physician based on: your overall health and medical history extent of the disease your tolerance for specific medications, procedures, or therapies expectations for the course of the disease your opinion or preference Treatment may i nclude modified antidiuretic hormone drugs or drugs to stimulate the production of the antidiuretic hormone. Anatomy of the Endocrine System hypothalamus What are hormones? Hormones are chemical substances created by the body that control numerous body functions. They actually act as "messengers" to coordinate functions of various body parts. Most hormones are proteins consisting of amino acid chains. Some hormones are steroids, fatty cholesterol-produced substances. Functions controlled by hormones include: activities of entire organs growth and development reproduction sexual characteristics usage and storage of energy levels of fluid, salt and sugar in the blood The hypothalamus is located in the brain, at the base of the optic chiasm. It secretes hormones that stimulate or suppress the release of hormones in the pituitary gland, in addition to controlling water balance, sleep, temperature, appetite, and blood pressure. pineal body The pineal body is located below the corpus callosum, a part of the brain. It produces the hormone melatonin. pituitary The pituitary gland is located at the base of the brain. No larger than a pea, the gland controls many functions of the other endocrine glands. thyroid and parathyroids The thyroid gland and parathyroid glands are located in front of the neck, below the larynx (voice box). The thyroid plays an important role in the body's metabolism. Both the thyroid and parathyroid glands also play a role in the regulation of the body's calcium balance. thymus The thymus is located in the upper part of the chest and produces Tlymphocytes (white blood cells that fight infections and destroy abnormal cells). adrenal gland The pair of adrenal glands are located on top of both kidneys. Adrenal glands work hand-in-hand with the hypothalamus and pituitary gland. kidney The pair of kidneys are located near the middle of the back, just below the rib cage. The kidneys process the blood to sift out waste products and extra water. This waste and extra water becomes urine, which is stored in the bladder. pancreas The pancreas is located across the back of the abdomen, behind the stomach. The pancreas plays a role in digestion, as well as hormone production. ovary A woman's ovaries are located on both sides of the uterus, below the opening of the fallopian tubes (tubes that extend from the uterus to the ovaries). In addition to containing the egg cells necessary for reproduction, the ovaries also produce estrogen and progesterone. testis A man's testes are located in a pouch that hangs suspended outside the male body. The testes produce testosterone and sperm.