Thyroid Disorders Flashcards
differentiate primary, secondary, and tertiary disorders.
primary disorders originate in the target endocrine gland responsible for producing the hormone.
With secondary disorders, the target endocrine gland is usually normal, but the gland is not producing appropriate levels of hormone because it is not receiving appropriate stimulation from the pituitary gland.
tertiary disorders result from hypothalamic dysfunction. Thus, both the pituitary and the target organ are understimulated.
name and contrast the thyroid hormones T3 and T4 by synthesis and action
T3: synthesized by a MIT and DIT residue.
T4: synthesized by two DIT residues.
T3 action: This hormone is at the center of your digestive and metabolic function, and it also oversees bone health.
T4 action: (T4) is responsible for your metabolism, mood, and body temperature, among other things.
define hypothyroidism Hashimoto (autoimmune thyroiditis) hyperthyroidism goiter myxedema exophthalmos gravEs disease thyroid storm
hypothyroidism: A condition in which the thyroid gland doesn’t produce enough thyroid hormone.
autoimmune thyroiditis: When the immune system attacks the thyroid.
hyperthyroidism: the over production of a hormone by the thyroid.
goiter: an increased in the size of the thyroid gland
myxedema: a general slowing down of metabolic processes in older children and adults that have hypothyroidism.
exophthalmos: Exophthalmos, also known as proptosis, is the medical term for bulging or protruding eyeballs. It can affect 1 or both eyes and is most often caused by thyroid eye disease.
graves disease: a state of hypErthyroidism, goiter and ophthalmopathy. autoimmune, characterized by abnormal stimulation of the thyroid gland by thyroid stimulating antibodies that act though normal TSH receptors.
thyroid storm: Thyroid storm is a life-threatening health condition that is associated with untreated or undertreated hyperthyroidism. During thyroid storm, an individual’s heart rate, blood pressure, and body temperature can soar to dangerously high levels. Without prompt, aggressive treatment, thyroid storm is often fatal.
list 4 causes of acquired hypothyroidism
- Hashimoto thyroiditis
- thyroidectomy
- Iodine Deficiency
- Subacute thyroiditis
describe clinical signs and treatment of hypothyroidism
hypometabolic state: characterized by a gradual onset of weakness and fatigue, a tendency to gain weight despite a loss of appetite, and cold intolerance.
myxedematous involvement of body tissues: characterized by an enlarged tongue, a hoarse and husky voice, carpal tunnel, impairment of muscle function with stiffness, cramps, and pain.
treatment is: replacement therapy with synthetic preparations of T3 or T4. Most people are treated with T4.
“low and slow” approach in the treatment of older people
stay on the same drug throughout treatment
describe clinical signs and treatment of hyperthyroidism
manifestations related to the increase in oxygen consumption and use of metabolic fuels associated with the hypermetabolic state.
nervousness, irritability, fatigability, weight loss despite a large appetite. Also tachycardia, SOB, palpitations, excessive sweating, muscle cramps and heat intolerance.
explain the negative feedback mechanism the thyroid hormones have on TSH from the pituitary gland
The thyroid hormones, T3 and T4, are regulated in much same way. When levels of T3 and T4 decrease below normal, the hypothalamus releases thyroid regulating hormone (TRH), stimulating the pituitary gland to produce thyroid stimulating hormone (TSH), which acts on the thyroid gland to produce more hormones and raise the blood levels. Once the levels rise, the hypothalamus “shuts off” and stops secreting TRH, which in turn inhibits the pituitary gland release of TSH.
contrast the expected serum levels of TSH and the thyroid hormones in conditions of hypo and hyperthyroidism
expected levels: 0.5 mU/L and 5.0 mU/L
TSH: hypothyroidism: above 5.0 mU/L. Indicates underactive thyroid–thus hypothyroidism
TSH: hyperthyroidism: below 0.5 mU/L. Indicates overactive thyroid–thus hyperthyroidism.
describe the actions of glucocorticoids and mineralocorticoids on target cells.
glucocorticoids (when produced as part of the stress response), aid in regulating the metabolic functions of the body and in controlling the inflammatory response.
mineralocorticoids play an essential role in regulating potassium and sodium levels and water balance.
explain basic lab abnormalities (electrolytes and glucose) in select adrenal problems (see lecture notes)
waiting on this one until she puts slides up.
explain the effects of long term steroid treatment on adrenal function, and relate these effects to the consequences of abrupt discontinuation.
Long-term steroid therapy can result in secondary adrenal insufficiency due to suppression of the hypothalamic-pituitary-adrenal axis.
Example with prednisone: your body can’t make enough cortisol right away to make up for the loss. This can cause a condition called prednisone withdrawal.
