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Alterations of Hormonal Regulation. Chapter 21. Elevated or Depressed Hormone Levels. Failure of feedback systems Dysfunction of an endocrine gland Secretory cells are unable to produce, obtain, or convert hormone precursors
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Alterations of Hormonal Regulation Chapter 21
Elevated or Depressed Hormone Levels • Failure of feedback systems • Dysfunction of an endocrine gland • Secretory cells are unable to produce, obtain, or convert hormone precursors • The endocrine gland synthesizes or releases excessive amounts of hormone • Increased hormone degradation or inactivation • Ectopic hormone release
Target Cell Failure • Receptor-associated disorders • Decrease in number of receptors • Impaired receptor function • Presence of antibodies against specific receptors • Antibodies that mimic hormone action • Unusual expression of receptor function
Diseases of the Posterior Pituitary • Syndrome of inappropriate antidiuretic hormone secretion (SIADH) • Hypersecretion of ADH • For diagnosis, normal adrenal and thyroid function must exist • Clinical manifestations are related to enhanced renal water retention, hyponatremia, and hypoosmolarity
Diseases of the Posterior Pituitary • Diabetes insipidus • Insufficiency of ADH • Polyuria and polydipsia • Partial or total inability to concentrate the urine • Neurogenic • Insufficient amounts of ADH • Nephrogenic • Inadequate response to ADH
Diseases of the Anterior Pituitary • Hypopituitarism • Pituitary infarction • Sheehan syndrome • Hemorrhage • Shock • Others: head trauma, infections, and tumors
Diseases of the Anterior Pituitary • Hypopituitarism • Panhypopituitarism • ACTH deficiency • TSH deficiency • FSH and LH deficiency • GH deficiency
Diseases of the Anterior Pituitary • Hyperpituitarism • Commonly due to a benign, slow-growing pituitary adenoma • Manifestations • Headache and fatigue • Visual changes • Hyposecretion of neighboring anterior pituitary hormones
Diseases of the Anterior Pituitary • Hypersecretion of growth hormone (GH) • Acromegaly • Hypersecretion of GH during adulthood • Gigantism • Hypersecretion of GH in children and adolescents
Diseases of the Anterior Pituitary • Hypersecretion of prolactin • Caused by prolactinomas • In females, increased levels of prolactin cause amenorrhea, galactorrhea, hirsutism, and osteopenia • In males, increased levels of prolactin cause hypogonadism, erectile dysfunction, impaired libido, oligospermia, and diminished ejaculate volume
Alterations of Thyroid Function • Hyperthyroidism • Thyrotoxicosis • Graves disease • Pretibial myxedema • Hyperthyroidism resulting from nodular thyroid disease • Goiter • Thyrotoxic crisis
Alterations of Thyroid Function • Hypothyroidism • Primary hypothyroidism • Subacute thyroiditis • Autoimmune thyroiditis (Hashimoto disease) • Painless thyroiditis • Postpartum thyroiditis • Myxedema coma • Congenital hypothyroidism • Thyroid carcinoma
Alterations of Parathyroid Function • Hyperparathyroidism • Primary hyperparathyroidism • Excess secretion of PTH from one or more parathyroid glands • Secondary hyperparathyroidism • Increase in PTH secondary to a chronic disease • Hypoparathyroidism • Abnormally low PTH levels • Usually caused by parathyroid damage in thyroid surgery
Type 1 Diabetes Mellitus • Demonstrates pancreatic atrophy and specific loss of beta cells • Macrophages, T and B lymphocytes, and natural killer cells are present • Two types • Immune • Nonimmune
Type 1 Diabetes Mellitus • Genetic susceptibility • Environmental factors • Immunologically mediated destruction of beta cells • Manifestations • Hyperglycemia, polydipsia, polyuria, polyphagia, weight loss, and fatigue
Dysfunction of the Pancreas • Type 2 diabetes mellitus • Maturity-onset diabetes of youth (MODY) • Gestational diabetes mellitus (GDM) • Common form of diabetes mellitus type 2 • Insulin resistance
Acute Complications of Diabetes Mellitus • Hypoglycemia • Diabetic ketoacidosis • Hyperosmolar hyperglycemic nonketotic syndrome (HHNKS) • Somogyi effect • Dawn phenomenon
Chronic Complications of Diabetes Mellitus • Hyperglycemia and nonenzymatic glycosylation • Hyperglycemia and the polyol pathway • Protein kinase C • Microvascular disease • Retinopathy • Diabetic nephropathy
Chronic Complications of Diabetes Mellitus • Macrovascular disease • Coronary artery disease • Stroke • Peripheral arterial disease • Diabetic neuropathies • Infection
Alterations of Adrenal Function • Disorders of the adrenal cortex • Cushing disease • Excessive anterior pituitary secretion of ACTH • Cushing syndrome • Excessive level of cortisol, regardless of cause
Alterations of Adrenal Function • Disorders of the adrenal cortex • Hyperaldosteronism • Primary hyperaldosteronism (Conn disease) • Secondary hyperaldosteronism
Alterations of Adrenal Function • Disorders of the adrenal cortex • Adrenocortical hypofunction • Primary adrenal insufficiency (Addison disease) • Idiopathic Addison disease • Secondary hypocortisolism
Alterations of Adrenal Function • Disorders of the adrenal cortex • Hypersecretion of adrenal androgens and estrogens • Feminization • Virilization
Alterations of Adrenal Function • Disorders of the adrenal medulla • Adrenal medulla hyperfunction • Caused by tumors derived from the chromaffin cells of the adrenal medulla • Pheochromocytomas • Secrete catecholamines on a continuous or episodic basis