>can occur in pt. with sever [neumonia, pneumothorax, & other disorders of the lungs. > Disorders of the central nervous system, such as head injury, brain surgery or tumor, and infection, are thought to produce SIADH by direct stimulation of the pituitary gland > Some medications (e.g., vincristine [Oncovin], phenothiazines, tricyclic antidepressants, thiazide diuretics) and nicotine have been implicated in SIADH MEDICAL MANAGEMNT > eliminating the underlying cause, if possible, and restricting fluid intake > Diuretic agents such as furosemide (Lasix) may be used along with fluid restriction if severe hyponatremia is present. NURSING MANAGEMENT >monitor fluid intake and output, daily weight, urine and blood chemistries and neurologic status is indicated for the patient at risk for SIADH. THE THYROID GLAND o Largest endocrine gland. Butterfly shaped o The thyroid gland produces three hormones: thyroxine (T 4 ) , triiodothyronine (T 3 ) , and calcitonin . o Various hormones and chemicals are responsible for normal thyroid function. Key among them are thyroid hormone, calcitonin, and iodine. THYROID HORMONE o Composed of T4 and T3. o Both are amino acid structures o T4 contains four iodine atoms, t3 contains 3 o Three thyroidbinding hormones—thyroxine-binding globulin (TBG), transthyretin (formerly known as thyroid-binding prealbumin), and albumin—bind and transport T3 and T4 SYNTHESIS OF THYROID HORMONE o Iodine essential for synthesis. o Major use of iodine is by the thyroid. Major derangement in iodine deficiency is alterations of thyroid function. REGULATION OF THYROID HORMONE o The secretion of T 3 and T 4 by the thyroid gland is controlled by TSH (also called thyrotropin ) from the anterior pituitary gland o TSH: controls rate of hormone release. o The level of thyroid hormone in the blood determines the release of TSH. o The term euthyroid refers to thyroid hormone production that is normal. o Environmental factors, such as a decrease in temperature, may lead to increased secretion of TRH, resulting in elevated secretion of thyroid hormones FUNCTIONS OF THYROID HORMONE > The main function of thyroid hormone is to control cellular metabolic activity. o The thyroid hormones influence cell replication and are important in brain development. o Thyroid hormone is also necessary for normal growth. o Thyroid hormones affect virtually every major organ system and tissue function, including the basal metabolic rate, tissue thermogenesis, serum cholesterol levels, and vascular resistance
CALCITONIN >secreted by thyroid gland. o Secreted in response to high plasma levels of calcium and it reduces the plasma level of calcium by increasing its deposition in bone. PATHOPHYSIOLOGY o Inadequate secretion of thyroid hormone during fetal and neonatal development results in stunted physical and mental growth (neonatal hypothyroidism) because of general depression of metabolic activity o IN ADULTS: hypothyroidism manifests as lethargy, slow mentation, and generalized slowing of body functions.
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