Endo Lectures

Study Guide: Endocrine System

I. Introduction

  • Endocrine System Function: Produces and releases hormones, works with the nervous system to maintain homeostasis. ​

II. Types of Glands ​

  • Exocrine Glands:

    • Sweat glands

    • Sudiferous glands

    • Ceruminous glands

  • Endocrine Glands:

    • Ductless, release hormones directly into the bloodstream ​

III. Hormones and Functions ​

  • Hormones: Chemical messengers that target specific organs. ​

  • Negative Feedback Mechanism:

    • Example: Insulin lowers blood sugar levels. ​

IV. Major Endocrine Glands and Hormones ​

  • Pituitary Gland

    • Anterior Pituitary (Adenohypophysis):

      • Growth Hormone (GH) ​

      • Adrenocorticotropic Hormone (ACTH) ​

      • Thyroid Stimulating Hormone (TSH) ​

      • Follicle Stimulating Hormone (FSH) ​

      • Luteinizing Hormone (LH) ​

      • Prolactin (PRL) ​

    • Posterior Pituitary (Neurohypophysis):

      • Antidiuretic Hormone (ADH) ​

      • Oxytocin

  • Thyroid Gland

    • Hormones: T3, T4, Calcitonin ​

  • Parathyroid Glands

    • Hormone: Parathyroid Hormone (PTH) ​

  • Adrenal Glands

    • Adrenal Cortex:

      • Mineralocorticoids (Aldosterone) ​

      • Glucocorticoids (Cortisol) ​

      • Sex Hormones (Estrogen, Testosterone) ​

    • Adrenal Medulla:

      • Epinephrine

      • Norepinephrine

  • Pancreas

    • Hormones: Insulin, Glucagon ​

  • Sex Glands

    • Ovaries: Estrogen, Progesterone ​

    • Testes: Testosterone ​

  • Thymus Gland

    • Hormone: Thymosin ​

  • Pineal Gland

    • Hormone: Melatonin ​

V. Endocrine Disorders

  • Pituitary Gland Disorders ​

    • Acromegaly: Overproduction of GH after puberty ​

      • Symptoms: Enlarged features, thickened skin, enlarged organs

      • Diagnosis: Elevated GH levels, growth hormone suppression test ​

      • Treatment: Medications (e.g., Dostenex), surgery, radiation

    • Gigantism: Overproduction of GH before puberty ​

      • Symptoms: Abnormally tall stature, long bones ​

      • Diagnosis: Elevated GH levels, growth hormone suppression test ​

      • Treatment: Medications, surgery, radiation ​

    • Dwarfism: Underproduction of GH ​

      • Symptoms: Short stature, well-proportioned body ​

      • Diagnosis: X-ray of wrist bones, decreased GH levels

      • Treatment: GH replacement therapy

    • Diabetes Insipidus (DI): Underproduction of ADH ​

      • Symptoms: Polyuria, polydipsia, dilute urine, dehydration ​

      • Diagnosis: Low urine specific gravity, high serum osmolality ​

      • Treatment: ADH replacement (Desmopressin, Vasopressin)

    • Syndrome of Inappropriate Antidiuretic Hormone (SIADH): Overproduction of ADH ​

      • Symptoms: Fluid retention, hyponatremia, concentrated urine ​

      • Diagnosis: Low serum osmolality, high urine specific gravity ​

      • Treatment: Fluid restriction, diuretics, declomycin

Study Guide: Diabetes Lecture

Overview of Diabetes

  • Definition: A systemic metabolic disorder that improperly uses/metabolizes carbs, fats, and proteins. ​

  • Types of Diabetes:

    • Type 1 Diabetes: Autoimmune disorder, no insulin production, typically in children, 10% of diabetics. ​

    • Type 2 Diabetes: Insulin resistance, typically in adults, 90% of diabetics, often related to obesity and sedentary lifestyle. ​

    • Gestational Diabetes: Occurs during pregnancy, increases risk of type 2 diabetes later. ​

Normal Insulin Function ​

  • Insulin: Hormone produced by beta cells in the pancreas, helps glucose enter cells from the bloodstream. ​

  • Normal Blood Sugar Levels: 70-100 mg/dL. ​

  • Insulin Secretion: Peaks 30 minutes after eating, returns to normal in 2-3 hours. ​

Diabetes Pathophysiology

  • Type 1 Diabetes: No insulin production due to autoimmune destruction of beta cells. ​

  • Type 2 Diabetes: Insulin resistance, pancreas overworks to produce insulin, eventually beta cells exhaust. ​

Symptoms and Diagnosis

  • Type 1 Diabetes: Thin, hyperglycemia, positive ketones in urine, polyuria, polydipsia, polyphagia. ​

  • Type 2 Diabetes: Often overweight, hyperglycemia, may have high blood pressure, hyperlipidemia. ​

  • Diagnostic Tools:

    • Random Blood Sugar: >200 mg/dL (suspicious). ​

    • Fasting Blood Sugar: >126 mg/dL (suspicious). ​

    • HbA1c: >6.5% (diagnostic). ​

    • Three-hour GTT: Diagnostic. ​

    • SMBG: Self-monitoring blood glucose for immediate levels. ​

Complications of Diabetes ​

  • Acute Complications:

    • Hypoglycemia: Blood sugar <70 mg/dL, symptoms include sweating, shaking, confusion. ​ Treat with quick-acting carbs or glucagon if unconscious. ​

    • DKA (Diabetic Ketoacidosis): Type 1, blood sugar 300-800 mg/dL, fruity breath, Kussmaul breathing, treat with IV fluids and insulin. ​

    • HHNC (Hyperglycemic Hyperosmolar Non-Ketotic Coma): Type 2, blood sugar 600-2000 mg/dL, profound dehydration, treat with large amounts of IV fluids and insulin. ​

  • Chronic Complications:

    • Blindness: Due to blood vessel damage in the eyes. ​

    • Cardiovascular Issues: Stroke, myocardial infarction. ​

    • Renal Failure: Due to blood vessel damage in the kidneys. ​

Management and Treatment

  • Type 1 Diabetes: Insulin therapy, diet, exercise.

  • Type 2 Diabetes: Diet, exercise, weight loss, oral hypoglycemic agents, possibly insulin. ​

  • Oral Hypoglycemic Agents:

    • Sulfonylureas: Increase insulin output (e.g., Glycotrol XL). ​

    • Megalotinides: Increase insulin release (e.g., Pranden). ​

    • Biguanides: Reduce hepatic glucose production (e.g., Metformin). ​

    • Alpha-glycosidase Inhibitors: Delay carbohydrate absorption. ​

    • Thiazolidinediones: Increase insulin sensitivity. ​

Special Considerations

  • Gestational Diabetes: Risk factors include age >25, overweight, family history. ​ Complications include larger babies, increased C-section rate, preterm labor, stillbirth, respiratory distress, and neonatal hypoglycemia. ​

Nursing Interventions

  • Monitor Blood Glucose Levels: Regular checks, especially during illness or stress. ​

  • Insulin Administration: Rotate injection sites, use correct syringe, do not massage injection site. ​

  • Patient Education: Importance of diet, exercise, foot care, and regular eye exams.

Key Points to Remember ​

  • Hypoglycemia Mnemonic: "Cold and clammy need some candy." ​

  • Hyperglycemia Mnemonic: "Hot and dry, sugar high." ​

  • DKA: Type 1, fruity breath, Kussmaul breathing. ​

  • HHNC: Type 2, profound dehydration, no ketones. ​

Endocrinology Study Guide

Thyroid Gland: ​

  • Hyperthyroidism (Graves' Disease): ​

    • Overproduction of T3, T4. ​

    • Symptoms: Weight loss, increased appetite, jitteriness, hyperactivity, insomnia, heart palpitations, tremors, elevated BP, exophthalmos (bulging eyes).

    • Diagnosis: Elevated T3, T4, decreased TSH. ​

    • Treatment: Antithyroid medications (PTU, Tapazol), radioactive iodine therapy, surgery (thyroidectomy).

    • Diet: High calorie, high protein, low fiber, avoid stimulants. ​

  • Hypothyroidism:

    • Underproduction of T3, T4. ​

    • Symptoms: Weight gain, cold intolerance, constipation, lethargy, depression, dry skin, hair loss.

    • Diagnosis: Decreased T3, T4, elevated TSH.

    • Treatment: Synthetic thyroid hormone (Synthroid, Levothyroid). ​

    • Diet: High protein, high fiber, low calorie, increased fluids. ​

Parathyroid Gland:

  • Hyperparathyroidism:

    • Overproduction of PTH. ​

    • Symptoms: Hypercalcemia, bone demineralization, pathologic fractures, kidney stones.

    • Diagnosis: Increased PTH, increased serum calcium, decreased serum phosphorus. ​

    • Treatment: Surgery (parathyroidectomy), low calcium diet, avoid antacids. ​

  • Hypoparathyroidism:

    • Underproduction of PTH. ​

    • Symptoms: Hypocalcemia, muscle spasms, tetany, laryngospasm. ​

    • Diagnosis: Decreased PTH, decreased serum calcium, increased serum phosphorus.

    • Treatment: IV calcium gluconate, vitamin D supplements, high calcium diet. ​

Adrenal Gland:

  • Cushing's Syndrome: ​

    • Overproduction of cortisol. ​

    • Symptoms: Moon face, buffalo hump, truncal obesity, thin arms and legs, hypertension, hyperglycemia, hypokalemia, osteoporosis, depression.

    • Diagnosis: Elevated cortisol levels. ​

    • Treatment: Surgery (adrenalectomy), radiation, medication (mitotane), cortisol replacement therapy.

    • Diet: Low calorie, low sodium, high potassium. ​

  • Addison's Disease: ​

    • Underproduction of cortisol and aldosterone. ​

    • Symptoms: Weakness, fatigue, hyperpigmentation, hypotension, hyponatremia, hyperkalemia, hypoglycemia.

    • Diagnosis: Decreased cortisol and aldosterone levels. ​

    • Treatment: Cortisol replacement (hydrocortisone), aldosterone replacement (Florinef), high sodium diet. ​

    • Emergency: Addisonian crisis (requires immediate hydrocortisone injection).

Adrenal Medulla:

  • Pheochromocytoma: ​

    • Tumor causing overproduction of epinephrine and norepinephrine. ​

    • Symptoms: Severe hypertension, headache, anxiety, sweating, tachycardia. ​

    • Treatment: Surgical removal of the tumor. ​

General Tips:

  • Understand the functions of each gland and the hormones they secrete. ​

  • Know the symptoms, diagnosis, and treatment for each disorder.

  • Make note cards for quick review of key points. ​

  • Pay attention to diet recommendations for each condition. ​

  • Remember the relationships between hormone levels and their effects on the body. ​