Endocrine Disorders



Endocrine Disorders





ADRENAL HYPOFUNCTION

Adrenal hypofunction is classified as primary or secondary.

Primary adrenal hypofunction or insufficiency (Addison’s disease) originates within the adrenal gland and is characterized by the decreased secretion of mineralocorticoids, glucocorticoids, and androgens. It’s defined as destruction of more than 90% of both adrenal glands and is usually caused by an autoimmune process. Addison’s disease is relatively uncommon and can occur at any age and in both sexes. Secondary adrenal hypofunction is due to impaired pituitary secretion of adrenocorticotropin (ACTH) and is characterized by decreased glucocorticoid secretion.

With early diagnosis and adequate replacement therapy, the prognosis for adrenal hypofunction is good.



Causes


Primary Hypofunction (Addison’s Disease)



  • Bilateral adrenalectomy


  • Hemorrhage into adrenal gland


  • Neoplasms


  • Tuberculosis, histoplasmosis, and cytomegalovirus


  • Family history of autoimmune disease


Secondary Hypofunction (Glucocorticoid Deficiency)



  • Hypopituitarism (causing decreased ACTH secretion)


  • Abrupt withdrawal of long-term corticosteroid therapy


  • Removal of an ACTH-secreting tumor


  • Pituitary injury by tumor or infiltrative or autoimmune process








CUSHING’S SYNDROME

Cushing’s syndrome is a cluster of clinical abnormalities caused by excessive adrenocortical hormones (particularly cortisol) or related corticosteroids and, to a lesser extent, androgens and aldosterone. Cushing’s disease (ACTH excess) accounts for about 70% of the cases of Cushing’s syndrome.



Causes



  • Pituitary hypersecretion of ACTH


  • Autonomous, ectopic ACTH secretion by a tumor outside the pituitary (usually malignant, frequently a pancreatic tumor or oat cell carcinoma of the lung)


  • Administration of synthetic glucocorticoids or steroids


  • Adrenal adenoma or a cancerous adrenal tumor







DIABETES INSIPIDUS

Adisorder of water metabolism, diabetes insipidus results from a deficiency of circulating vasopressin (also called antidiuretic hormone, or ADH) or from renal resistance to this hormone. The three forms of diabetes insipidus are neurogenic, nephrogenic, and psychogenic. Neurogenic diabetes insipidus is caused by a deficiency of ADH; nephrogenic diabetes insipidus, by the resistance of renal tubules to ADH. Diabetes insipidus is characterized by excessive fluid intake and hypotonic polyuria. A decrease in ADH levels leads to altered intracellular and extracellular fluid control, causing renal excretion of a large amount of urine.



Causes



  • Neurogenic: stroke, hypothalamic or pituitary tumor, cranial trauma, or surgery


  • Nephrogenic: X-linked recessive trait, end-stage renal failure


  • Psychogenic: primary polydipsia or sarcoidosis


  • Transient diabetes insipidus: certain drugs, such as lithium, phenytoin, or alcohol







DIABETES MELLITUS

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia resulting from lack of insulin, lack of insulin effect, or both. Three general classifications are recognized:



  • type 1 — absolute insulin insufficiency


  • type 2 — insulin resistance with varying degrees of insulin secretory defects


  • gestational diabetes — manifested during pregnancy.



Causes



  • Heredity


  • Environment (infection, toxins)


  • Stress, diet, and lack of exercise in genetically susceptible persons


  • Pregnancy



Sep 22, 2018 | Posted by in ANATOMY | Comments Off on Endocrine Disorders
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