Endocrine - Lecture Notes

Key Points: Endocrine System: A ductless system that secretes hormones directly into the bloodstream. Hormones: Chemical messengers that target specific organs to stimulate their functions. Endocrine Organs: Pituitary, thyroid, parathyroid, pancreas, adrenals, ovaries, testes. Disease Concept: Hyper: Excessive hormone production Hypo: Insufficient hormone production Hyperthyroidism: Causes: Tumor, idiopathic, metabolic conditions, genetics, drugs Diagnosis: Blood test, imaging studies Management: Anti-thyroid drugs, surgery, radiation, palliative care Hypothyroidism: Causes: Trauma, infection, autoimmune diseases, metabolic conditions, genetics, congenital Diagnosis: Blood test, imaging studies Management: Hormone replacement, palliative care Pituitary Gland: A master gland that regulates other endocrine glands. Hormones: Releases hormones that control various body functions. Hypothalamus: Produces hormones that stimulate the pituitary gland. Parts of the Pituitary: Anterior and posterior lobes. Anterior Lobe Hormones: Growth Hormone (GH): Stimulates growth, metabolism, and protein synthesis. Thyroid-Stimulating Hormone (TSH): Stimulates thyroid hormone production. Adrenocorticotropic Hormone (ACTH): Stimulates adrenal hormone production. Luteinizing Hormone (LH): Regulates ovulation and testosterone production. Follicle-Stimulating Hormone (FSH): Stimulates egg and sperm production. Prolactin: Stimulates milk production. Posterior Lobe Hormones: Oxytocin: Stimulates uterine contractions and milk letdown. Antidiuretic Hormone (ADH): Regulates water balance in the body. Hyper and Hyposecretion Conditions: Growth Hormone: Gigantism (excess) and dwarfism (deficiency). Thyroid Hormone: Hyperthyroidism and hypothyroidism. Adrenocorticotropic Hormone: Cushing's syndrome and Addison's disease. Luteinizing Hormone and Follicle-Stimulating Hormone: Infertility and sexual dysfunction. Prolactin: Galactorrhea and infertility. Oxytocin: Failure of uterine contractions and milk letdown. Antidiuretic Hormone: Syndrome of inappropriate ADH secretion (SIADH) and diabetes insipidus. Thyroid-Stimulating Hormone (TSH): Regulates thyroid hormone production. Prolactin: Stimulates milk production. Adrenocorticotropic Hormone (ACTH): Stimulates adrenal hormone production. Luteinizing Hormone (LH): Regulates sex hormones. Hyper and Hyposecretion Conditions: TSH: Hyperthyroidism and hypothyroidism. Prolactin: Galactorrhea and infertility. ACTH: Cushing's syndrome and Addison's disease. LH: Gynecomastia (in men) and breast atrophy (in women). Follicle-Stimulating Hormone (FSH): Regulates egg and sperm development. Melanocyte-Stimulating Hormone (MSH): Regulates skin pigmentation. Thyroid Hormones: T3 (triiodothyronine) and T4 (thyroxine). Thyroid Hormone Functions: Regulate cellular metabolism, body functions, weight, menses, sleep, and heat tolerance. Hyperthyroidism: Symptoms: Increased cell function, weight loss, menses, sleep, heat tolerance. Common Conditions: Graves' disease, toxic nodular goiter. Serious Condition: Thyroid storm. Hypothyroidism: Symptoms: Decreased cell function, weight gain, menses, sleep, cold intolerance. Common Conditions: Hashimoto's disease, myxedema. Serious Condition: Myxedema coma and loss of consciousness. Parathyroid Gland: Function: Regulates calcium levels in the blood. Hormone: Parathyroid hormone (PTH). Hyperparathyroidism: High PTH levels, leading to increased blood calcium. Hypoparathyroidism: Low PTH levels, leading to decreased blood calcium. Pancreas: Exocrine Function: Produces digestive enzymes (amylase, lipase, trypsin) for digestion of carbohydrates, fats, and proteins. Endocrine Function: Produces hormones insulin and glucagon. Islets of Langerhans: Clusters of cells in the pancreas that produce hormones. Alpha Cells: Produce glucagon, which increases blood sugar levels. Beta Cells: Produce insulin, which decreases blood sugar levels. Diabetes Mellitus: Type 1: Autoimmune disease where the body does not produce insulin. Type 2: Body becomes resistant to insulin. Management: Insulin therapy, oral hypoglycemic agents.