Endocrine Flashcards
Thyroid hormones, triiodothyronine ____and thyroxine ___, are regulated by thyroid-stimulating hormone (TSH) secretion from the anterior pituitary
T3; T4
Thyroid hormones produced in follicular cells of thyroid
Regulators of _____; required for normal growth and development of tissues
METABOLISM
May be congenital or acquired
Majority are primary, due to intrinsic thyroid gland dysfunction
hypothyroidism
______hypothyroidism (cretinism) typically due to thyroid dysgenesis (lack of development)
Congenital
_________hypothyroidism due to defects in TSH production (hyposecretion) usually associated with head/brain conditions
Secondary
Most common cause of acquired hypothyroidism:
lymphocytic thyroiditis (Hashimoto or autoimmune thyroiditis)
Irradiation of the thyroid gland
Surgical removal of thyroid tissue
can lead to
hypothyroidism
_____deficiency (required for T3, T4 formation) leads to _____
iodine; hypothyroidism
Iodine deficiency (required for T3, T4 formation)
Leads to lack of T3/T4, stimulates ___ secretion
Increased ____causes thyroid cells to secrete large amounts of thyroglobulin, which leads to ____ in hypothyroidism
TSH; TSH; goiter
Decreased basal metabolic rate
Weakness, lethargy, cold intolerance, decreased appetite
Bradycardia, narrowed pulse pressure, and mild/moderate weight gain
signs of
hypothyroidism
Elevated serum cholesterol and triglycerides
Enlarged thyroid, dry skin, constipation
Depression, difficulties with concentration/memory
signs of ______
hypothyroidism
Loss of eyebrow
Menstrual irregularity
signs of _____
hypothyroidism
Primary diagnosis of hypothyroidism
elevated TSH
Secondary diagnosis of hypothyroidism
low TSH
Low levels of T3 and T4 may not occur until later in the disease course OF _____
hypothyroidism
Goal is return of euthyroid (normal) state
Must progress slowly
hypothyroidism
Oral levothyroxine
Resolution of symptoms occurs over weeks
hypothyroidism
_______occurs in severe or prolonged hypothyroidism
Myxedema
Generalized, non-pitting edema
Decreased level of consciousness, hypotension, hypothermia, history of precipitating event (trauma, sepsis, certain drugs)
May progress to myxedema coma, a life-threatening condition if treatment not received
Myxedema
Thyroid hyperfunction with _____synthesis and secretion of T4 and T3 (Graves disease) causes _____
increased; hyperthyroidism
Thyroid destruction with release of preformed T4 and T3 (Hashimoto thyroiditis)
hyperthyroidism
Graves disease, autoimmune, tumor related, inflammatory examples of _______
primary hyperthyroidism
primary hyperthyroidism IS ______
autoimmune
Stimulation of TSH receptors by TSH (hypersecretion of TSH) caused by ________
secondary hyperthyroidism
Most common form of _____: autoantibodies bind and stimulate TSH receptors leading to diffuse toxic goiter which is _____
hyperthyroidism; Graves disease
Associated with certain genetic markers
Thyromegaly
symptoms of ______
hyperthyroidism
Exophthalmos (immune mediated so may not resolve with treatment)
Widening of the palpebral fissure resulting in exposed sclera
Lid lag, vision changes, photophobia
symptoms of _______
hyperthyroidism
Changes in behavior, insomnia, restlessness, tremor, irritability, palpitations, heat intolerance, diaphoresis, diarrhea, inability to concentrate that interferes with work performance; enlarged thyroid gland
Increased basal metabolic rate leads to weight loss, although appetite and dietary intake increase
Amenorrhea/scant menses
symptoms of ______
hyperthyroidism
Elevated serum T4 and T3 (confirm) _____
hyperthyroidism
24-hour radioactive iodine uptake study can confirm diagnosis of _____ and exclude presence of thyroid neoplasms
Graves disease
Primary hyperthyroidism has _____ TSH, secondary has ____
low; high
Beta-blockers to block acute symptoms
Antithyroid drugs, thionamides (propylthiouracil, methimazole)
treat
hyperthyroidism
Radioactive iodine treatment (destroys part of thyroid for
Graves disease
Surgical removal of the thyroid gland typically reserved for tumors
Pituitary adenoma treated surgically
treatment for
hyperthyroidism
Life-threatening thyrotoxicosis that occurs when excessive amounts of thyroid hormones are acutely released into circulation
thyroid storm
Elevated temperatures, tachycardia, arrhythmias, congestive heart failure
Extreme restlessness, agitation, and psychosis
Precipitating event: stress, gland manipulation
symptoms of ____
thyroid storm