Pathophysiology

Pathophysiology Study Guide

Diabetes Insipidus Diabetes insipidus is a rare disorder in which the affected person suffers from intense thirst, irrespective of drinking fluids, and excretes too much urine. This disorder is characterized by improper production, storage, and release of a key hormone called anti-diuretic hormone (ADH). In normal situations, with the fall in the fluid intake, the urine produced by the kidneys fall. In the case of diabetes insipidus, the kidneys remove excess fluid from the blood. The fluid intake is regulated by the mechanism of thirst, while the excretion is influenced by the production of ADH hormone. The body makes ADH in the hypothalamus and stores it in the pituitary gland. When the body feels dehydrated, ADH is released into the blood, triggering kidney tubules, which release the fluid back in the blood, to not excrete it as urine. In the case of diabetes insipidus, this system is disturbed. There are different categories of diabetes insipidus including: • Central diabetes insipidus: This disorder is characterized by the damage of the pituitary gland or hypothalamus, which may be caused by a tumor, surgery, meningitis, genetic disorders, head inflammation, and injury. • Nephrogenic diabetes insipidus: This disorder is caused by a defect in the tubules of the kidney such that they fail to respond to the ADH hormone properly. This defect can be caused by inheriting the defect, a chronic kidney disorder, or certain medicines like lithium and demeclocycline. • Gestational diabetes insipidus: This kind of diabetes insipidus occurs in pregnancy when the placenta destroys the ADH hormone in the mother. • Primary polydipsia: This leads to the excretion of a large amount of diluted urine, which is due to a large fluid intake. Prolonged intake of fluids damages the kidneys and suppresses ADH such that the concentration of urine falls. It can also be due to mental illness. Signs and symptoms of diabetes insipidus include extreme thirst, excreting a large amount of diluted urine, weight loss, delayed growth, unexplained fussiness, fever, vomiting, diarrhea, and dry skin with cool extremities. 7.9 Alterations of Thyroid Function and Parathyroid Function Hyperthyroidism Hyperthyroidism is the condition characterized by an overactive thyroid, in which the thyroid gland produces excess thyroxin hormone. This leads to the acceleration of metabolism of the body. The thyroid gland produces two hormones, thyroxin and triodothyronine. The pituitary gland and hypothalamus control the rate at which these two hormones are released. These hormones are responsible for using fats and carbohydrates, controlling body temperature, regulating heart rate, and influencing the production of proteins. Some disorders that can cause hyperthyroidism are Grave's disease, toxic adenoma, toxic multi-nodular goiter, Plummer's disease, and thyroiditis. Signs and symptoms of hyperthyroidism are unintended weight loss, tachycardia, rise in appetite, nervousness, anxiety, irritation, tremor, sweating, alterations in menstrual cycles, rise in heat sensitivity, increase in bowel movements, difficulty sleeping, brittle hair, thinning of the skin, and weakness in muscles.

©2018

Achieve

Page 122

of 131

Made with FlippingBook - professional solution for displaying marketing and sales documents online