Mod 10 Endocrine Disorders Flashcards
Hypopituitarism (pituitary insufficiency)
Etiology: pituitary tumor, complications following brain surgery, or radiation of a brain tumor. Caused by trauma, ischemia, infarction, or hemorrhage. Sheehan’s syndrome is pituitary ischemia
Patho: tropic hormone production is reduced –> target gland hormone production is decreased
CM: The signs and symptoms of pituitary insufficiency are dependent upon which tropic hormones are not secreted
The most serious concerns are adrenal insufficiency, hypothyroidism, and diabetes insipidus (DI)
Weakness, weight loss, and hypotension caused by adrenal insufficiency, or weight gain, sluggishness, and depression caused by hypothyroidism. Lack of ADH causes excessive urination and dehydration, a syndrome known as DI.
Diabetes Insipidus (hypo pituitary)
Central DI = occurs because of a lack of secretion of ADH from the posterior pituitary
Nephrogenic DI = occurs when the kidney fails to respond to ADH.
Etiology: tumors or head trauma that causes injury of the posterior pituitary
Patho: Nephron does not perform antidiuresis (the nephron does not reabsorb water from the tubule fluid) Results in the body loses high amounts of water in the urine –> polyuria and highly dilute urine. The bloodstream loses water, which concentrates its sodium content, causing hypernatremia, polyuria, dilute urine, and dehydration
CM: dehydration and hypernatremia. The patient will report frequent urination (polyuria) and thirst (polydipsia)
Dehydration leads to neurological problems: confusion, disorientation, seizures
SIADH (Syndrome of inappropriate antidiuretic hormone) (hyper pituitary)
Hyponatremia and hyposmolality of the blood from excessive secretion or action of ADH
Etiology: NS disorders such as stroke and meningitis, lung and colon cancer, emphysema and pneumonia.
SIADH can be a side effect of brain injury, brain surgery, or may be secreted by tumors (lung cancer).
Patho: ADH is synthesized by the hypothalamus and transmitted via nerve tracts to the posterior pituitary, where it is stored and secreted. Essential for fluid balance in the body, ADH stimulates reabsorption of water at the collecting duct of the nephron. SIADH causes excess water reabsorption into the bloodstream. This excess water creates hypervolemia, dilutional hyponatremia, and highly concentrated urine.
CM: fluid volume overload and dilutional hyponatremia, including fatigue, weakness, confusion, and headache
Goiter (hypothyroid)
An enlargement of the thyroid gland with or without symptoms of thyroid dysfunction
*What does iodine have to do with this?
Iodine levels are decreased in body –> thyroid hormone synthesis is diminished bc iodine is necessary in the synthesis of thyroid hormone.
Low iodine levels cause low thyroid hormone manufacture, which the pituitary senses and then attempts to compensate for by increasing TSH, which incites goiter formation.
Hypothyroidism
Insufficient levels of the thyroid hormones T3 and T4
Etiology: thyroid gland produces insufficient amounts of thyroid hormone. Risk factors include age older than 50 years; female gender; pregnancy; autoimmune disease; radiation to the neck; family history; and certain drugs, including radioactive iodine, amiodarone, interferon alpha, interleukin, and lithium.
Patho: antibodies bind to the TSH receptor, there is an absence of the normal response of T3 and T4 synthesis and secretion
CM: Reduction in the conversion of carotene to vitamin A causes hypercarotenemia, which gives skin a yellow-orange tint. A puffy face occurs because of accumulation of sodium and water from protein/polysaccharide complex deposits. A characteristic hoarse voice also develops. Reduced levels of low-density lipoprotein (LDL) receptors in the liver lead to elevations in cholesterol and triglycerides. Anemia. cold intolerance, weight gain, lethargy, and fatigue. Other symptoms include memory deficits, poor attention span, muscle cramps, constipation, decreased fertility, puffy face, hair loss, and brittle nails. In the adult, severe hypothyroidism is called myxedema
Hyperthyroidism
Excessive secretion of the thyroid hormones T3 and T4. The most common etiology is Graves’ disease
Etiology: Graves’ disease, subacute thyroiditis, an inflammation of the thyroid gland that causes release of excessive thyroid hormone, Toxic multinodular goiter, also called Plummer’s disease
Patho: thyroid gland secretes an excessive amount of thyroid hormone. Thyroid-stimulating antibodies bind to and activate thyrotropin receptors within the thyroid gland, causing the gland to enlarge and continually synthesize thyroid hormones
CM: nervousness, insomnia, sensitivity to heat, and weight loss
Hyper parathyroid
Etiology: excessive secretion of PTH that affects calcium homeostasis in the body
Patho: caused by an adenoma. The growth in the parathyroid gland causes excessive secretion of PTH with resulting high levels of calcium in the blood. Any disorder that causes hypocalcemia can cause stimulation of the parathyroid gland and resultant hyperparathyroidism.
CM: excessive levels of calcium. The most common effects of hypercalcemia include muscle weakness, poor concentration, neuropathies, hypertension, kidney stones, metabolic acidosis, osteopenia, pathological fractures, and constipation. depression, confusion
Hypo parathyroid
Etiology: trauma or inadvertent damage or removal of the parathyroid glands during thyroid surgery
CM: insufficient PTH secretion and the resultant decrease in serum calcium levels. low levels of calcium. The patient can present with muscle cramps, irritability, tetany, and convulsions. Hypocalcemia also causes a carpal spasm known as Trousseau’s sign and facial muscle twitch called Chvostek’s sign
Cushing’s (Hyperadreninalism)
Etiology: caused by high levels of cortisol in the blood.
Syndrome is caused by hyperactive adrenal gland that secretes excess cortisol
Disease is caused by tumor in pituitary that produces large amounts of ACTH
Does not respond with rise in ACTH level in time of stress/trauma.
Fat redistribution, striae, easy bruising, poor wound healing, hirsutism
CM: Weight gain, rose-colored, puffy face called “moon facies,” as well as extra subcutaneous fat in the cervicothoracic area called “buffalo hump.” Hyperglycemia, osteoporosis,
What does high cortisol levels counteracting with insulin lead to?
High cortisol levels counteract insulin leading to hyperglycemia, accelerate bone breakdown, leading to osteoporosis, elevate BP causing HTN, and diminish efficiency of WBCS leading to immunosuppression.
Addison’s (Hypoaderenalism)
Etiology: Adrenal insufficiency
Patho: Gradual autoimmune destruction of the adrenal gland leads to a decreased cortisol response to stress and reduced cortisol reserve. As the glandular destruction increases, less cortisol is available, and this can lead to adrenal crisis
CM: tanned appearance, weakness, hypotension, lethargy, easy fatigue, anorexia, nausea, and vomiting. personality changes, inability to concentrate, and emotional lability. In women, there is loss of pubic and axillary hair and amenorrhea
hyponatremia, hyperkalemia due to lack of aldosterone
adrenal gland downregulates after 4-5 weeks on prednisone, gland atrophies
In stress situations, the normal adrenal gland output of cortisol is approximately 250-300 mg in 24 hours. This amount of hydrocortisone should be given parenterally by continuous infusion after trauma
