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Explore alterations in hormonal regulation, including elevated or depressed hormone levels, target cell failures, and diseases affecting the pituitary and thyroid. Learn about manifestations, diagnosis, and complications.
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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