Disease Flashcards
(40 cards)
Disease Focus
Disorders of the endocrine system are caused by underproduction (hyposecretion) or overproduction (hypersecretion) of hormones. In general, hyposecretion is treated with drug therapy in the form of hormone replacement. Hypersecretion is generally treated with surgery. Most hormone deficiencies result from genetic defects in the glands, surgical removal of the glands, or production of poor-quality hormones. For diagnosis, treatment, and management of endocrine disorders, the medical services of a specialist may be warranted. Endocrinology is the branch of medicine concerned with endocrine glands and hormones. The physician who specializes in the diagnosis and treatment of endocrine disorders is known as an endocrinologist.
Thyroid Disorders
Thyroid gland disorders are common and may occur at any time during life. They may be the result of a developmental problem, injury, disease, or dietary deficiency.
Deficiency of thyroid hormone (hypothyroidism) that develops in infants is called____. If not treated, this disorder leads to mental retardation, impaired growth,___ body temperatures, and abnormal___ formation. Usually these symptoms do not appear at birth because the infant has received thyroid hormones from the mother’s blood during fetal development. When hypothyroidism develops during adulthood, it is known as____. The signs and symptoms of this disease include edema, low blood levels of T3 and T4, weight gain, cold intolerance, fatigue, depression, muscle or joint pain, and sluggishness.
cretinism
low
bone myxedema
______is a condition in which the thyroid gland produces excessive amounts of thyroid hormone. The most common form is____ disease, also known as ____toxicosis/autoimmune hyperthyroidism, an autoimmune disorder in which the immune system produces autoantibodies that stimulate the production of excessive thyroid hormone. Another cause of hyperthyroidism is the formation of nodules or lumps on the thyroid gland (toxic nodular or multinodular hyperthyroidism), causing the excess production of thyroid hormone.
Hyperthyroidism
Graves
Thyro
Signs and symptoms of hyperthyroidism include an elevated metabolic rate, abnormal weight loss, excessive ____iration, muscle weakness, and emotional instability. Also, the eyes are likely to protrude (_____almos) because of edematous swelling in the tissues behind them. (See Fig. 14-3.) At the same time, the thyroid gland is likely to enlarge, producing____. Treatment for hyperthyroidism may involve drug therapy to block the production of thyroid hormones or surgical removal of all or part of the thyroid gland. Another method for treating this disorder is to administer a sufficient amount of radioactive____ to destroy the thyroid secretory cells.
Graves exophth
goiter
iodine
Parathyroid Disorders
As with the thyroid gland, dysfunction of the parathyroids is usually characterized by inadequate or excessive hormone secretion. Insufficient production of parathyroid hormone (PTH), called hypoparathyroidism, may be caused by primary parathyroid dysfunction or____ blood calcium levels. This condition can result from an injury or from surgical removal of the glands, sometimes in conjunction with thyroid surgery. The primary effect of hypoparathyroidism is a decreased blood calcium level (___). Decreased calcium causes muscle twitches and spasms (____).
elevated hypocalcemia tetany
Excessive production of PTH, called hyperparathyroidism, is commonly caused by a benign tumor. The increase in PTH secretion leads to demineralization of bones (osteitis fibrosa cystica), making them porous (osteoporosis) and highly susceptible to fracture and deformity. When this condition is the result of a benign glandular tumor (adenoma) of the parathyroid, the tumor is removed. Excess PTH also causes calcium deposits in the kidneys
Adrenal Gland Disorders
The adrenal cortex and adrenal medulla have their own structures and functions and their own sets of associated disorders.
Adrenal Cortex
The adrenal cortex is mainly associated with Addison disease and Cushing syndrome.
Addison Disease
Addison disease, also called corticoadrenal insufficiency, is a relatively uncommon chronic disorder caused by a deficiency of cortical hormones. It commonly results from damage to or atrophy of the adrenal cortex. Hypofunction of the adrenal cortex interferes with the body’s ability to handle internal and external stress. Other clinical manifestations include muscle weakness, anorexia, gastrointestinal symptoms, fatigue, hypoglycemia, hypotension, low blood sodium (hyponatremia), and high serum potassium (hyperkalemia). If treatment for this condition begins early (usually with adrenocortical hormone therapy), the prognosis is excellent. If untreated, the disease will continue a chronic course with progressive but relatively slow deterioration. In some patients, the deterioration may be rapid.
Cushing Syndrome
Cushing syndrome is a cluster of symptoms produced by excessive amounts of cortisol, adrenocorticotropic hormone (ACTH), or both circulating in the blood. (See Fig. 14-5, page 490.)
Causes of this excess secretion include the following:
• Long-term administration of steroid drugs (glucocorticoids) in treating such diseases as rheumatoid arthritis, lupus erythematosus, and asthma
• Adrenal tumor, resulting in excessive production of cortisol
• Cushing disease, a pituitary disorder caused by hypersecretion of ACTH from an adenoma in the anterior pituitary gland.
Regardless of the cause, Cushing syndrome alters carbohydrate and protein metabolism and electrolyte balance. Overproduction of mineralocorticoids and glucocorticoids causes blood glucose concentration to remain high, depleting tissue protein. In addition, sodium retention causes increased fluid in tissues, leading to edema.
These metabolic changes produce weight gain and may cause structural changes, such as a moon-shaped face, grossly exaggerated head and trunk, and pencil-thin arms and legs. Other symptoms include fatigue, high blood pressure, and excessive hair growth in unusual places (hirsutism), especially in women. The treatment goal for this disease is to restore serum cortisol to normal levels. Nevertheless, treatment varies with the cause and may necessitate radiation, drug therapy, surgery, or a combination of these methods.
Adrenal Medulla
No specific diseases can be traced directly to a deficiency of hormones from the adrenal medulla. However, medullary tumors sometimes cause excess secretions. The most common disorder is a neoplasm known as pheochromocytoma, which produces excessive amounts of epinephrine and norepinephrine. Most of these tumors are encapsulated and benign. These hypersecretions produce high blood pressure, rapid heart rate, stress, fear, palpitations, headaches, visual blurring, muscle spasms, and sweating. Typical treatment consists of antihypertensive drugs and surgery.
Pancreatic Disorders
By far, the most common pancreatic disorder is diabetes. Diabetes is a general term that, when used alone, refers to diabetes mellitus (DM). DM is a chronic metabolic disorder of impaired carbohydrate, protein, and fat metabolism resulting from insufficient production of insulin or the body’s inability to use insulin properly. When body cells are deprived of glucose, their principal energy fuel, they begin to metabolize proteins and fats. Fat metabolism produces ketones, which enter the blood, causing a condition called ketosis. Hyperglycemia and ketosis are responsible for the host of troubling and, commonly, life-threatening symptoms of diabetes mellitus. Although genetics and environmental factors, such as obesity and lack of exercise, seem significant in the development of this disease, the cause of diabetes is not always clear. Diabetes mellitus occurs in two primary forms: type 1 and type 2.
Type 1 Diabetes
Type 1 diabetes is an autoimmune disease. It is usually diagnosed in children and young adults. In type 1 diabetes, the body does not produce a sufficient amount of insulin. Like all autoimmune diseases, it requires constant monitoring and medicating. Blood glucose levels are monitored by the patient several times a day using a glucometer to determine the amount of insulin needed to control blood sugar levels. The patient administers insulin injections as needed. Insulin injections should be administered in a different subcutaneous site each time to avoid injury to the tissues. (See Fig. 14-6.)
Type 2 Diabetes
In type 2 diabetes, either the body’s cells are resistant to insulin or the pancreas is deficient in producing insulin. In both cases, the body’s cells do not absorb glucose, and it remains in the blood, causing hyperglycemia. Type 2 diabetes is the most common form and is distinctively different from type 1. Its onset is typically later in life; however, it has become more prevalent in children as the incidence of obesity has increased. Risk factors include a family history of diabetes and obesity. Treatment for type 2 diabetes includes exercise, diet, weight loss, and insulin or oral antidiabetic agents, if needed. (See Table 14-6.)
Oncology
Oncological disorders of the endocrine system vary based on the organ involved and include pancreatic cancer, pituitary tumors, and thyroid carcinoma. Pancreatic Cancer
Most carcinomas of the pancreas arise as epithelial tumors (adenocarcinomas) and make their presence known by causing obstructions and local invasion. Because the pancreas is richly supplied with nerves, pain is a prominent feature of pancreatic cancer, whether it arises in the head, body, or tail of the organ.
type 1 diabetes
• Symptoms usually start in childhood or young adulthood.
• Patients commonly seek medical attention because they experience serious symptoms associated with a high blood glucose level.
• Episodes of low blood glucose level (hypoglycemia) are common.
• Prevention is not possible.
type 2 diabetes
• The disease is usually discovered during a routine checkup, commonly before symptoms occur.
• It is commonly diagnosed in adulthood, but an increasing number of children are being diagnosed with the disease.
• There are no episodes of low blood glucose level, unless the person is taking excessive insulin or certain diabetes medicines.
• Healthy lifestyle measures to prevent or delay onset include maintaining a healthy weight, eating sensibly, and exercising regularly.
Both types of diabetes greatly increase a person’s risk for a range of serious complications. Although monitoring and managing the disease can prevent complications, diabetes remains the leading cause of blindness and kidney failure. It also continues to be a critical risk factor for heart disease, stroke, and foot or leg amputations. The prognosis in pancreatic cancer is poor, with only a 2% survival rate in 5 years. Pancreatic cancer is the fourth leading cause of cancer death in the United States. The highest incidence is among people ages 60 to 70. The etiology is unknown, but cigarette smoking, exposure to occupational chemicals, a diet high in fats, and heavy coffee intake are associated with an increased incidence of pancreatic cancer.
Pituitary Tumors
Pituitary tumors are abnormal growths that develop in the pituitary gland. Some pituitary tumors cause excessive production of hormones that regulate important functions of the body. Other pituitary tumors can restrict normal function of the pituitary gland, causing it to produce lower levels of hormones. The vast majority of pituitary tumors are noncancerous (benign) growths known as adenomas. Adenomas remain confined to the pituitary gland or surrounding tissues and do not spread to other parts of the body. As the tumor grows, it can cause a variety of symptoms, including compression of nearby nerves, resulting in vision problems. Treatment involves removing the tumor, especially if it is pressing on the optic nerves, which could cause blindness.
Removal of pituitary tumors commonly occurs through the nose and sphenoid sinuses (transsphenoidal hypophysectomy). Other treatment modalities include restoring normal hormone levels or radiation therapy to shrink the tumor. These treatments occur in combination with surgery or for patients who cannot tolerate surgery.
Thyroid Carcinoma
Cancer of the thyroid gland, or thyroid carcinoma, is classified according to the specific tissue that is affected. In general, however, all types share many predisposing factors, including radiation, prolonged TSH stimulation, familial disposition, and chronic goiter. The malignancy usually begins with a painless, commonly hard nodule or a nodule in the adjacent lymph nodes accompanied by an enlarged thyroid. When the tumor is large, it typically destroys thyroid tissue, which results in symptoms of hypothyroidism. Sometimes the tumor stimulates the production of thyroid hormone, resulting in symptoms of hyperthyroidism. Treatment includes surgical removal, radiation, or both.
diabetes insipidus (DI)
dī-ă-BĒ-tēzĭn-SĬP-ĭ-dŭs
Disorder characterized by excessive thirst (polydipsia) and excessive urination (polyuria) due to inadequate production of antidiuretic hormone (ADH)
diuresis
dī-ū-RĒ-sĭs
di-: double
ur: urine
-esis: condition
Increased formation and secretion of urine
Diuresis commonly occurs in diabetes mellitus. Alcohol and coffee are common diuretics that increase formation and secretion of urine.
