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Endocrine System Jane Bordner, RN BSN Nursing Instructor HACC, Central Pennsylvania’s Community College N100 Spring 2015 Endocrine System • Works with nervous system to maintain homeostasis • Consists of organs that secrete chemical messengers called hormones and neurohormones Endocrine System • Regulates – growth – reproduction – use of nutrients by cells – electrolyte and fluid balance – metabolic rate • Helps us cope with stress Feedback Control Mechanism • • • • • Glands are controlled by feedback system Circulating hormone is monitored by gland Has affect on secretion of hormone Gland responds in homeostatic manner Usually a negative feedback system Negative Feedback System Positive Feedback System Endocrine Glands Pituitary Gland • Hypophoysis = Master gland • Secretes 9 distinct hormones • Hormones control activities of several other endocrine glands – Thyroid – Parathyroid – Adrenal – Pancreas – Ovaries and testicles Pituitary Gland • Consists of three lobes – Posterior = 2 hormones – Anterior = 6 hormones – Middle = 1 hormone Pituitary Gland: Posterior Lobe • Oxytocin • Uterine contractions • Ejection of milk from breasts Pituitary Gland: Posterior Lobe • Antidiuretic Hormone (ADH) – Regulates fluid balance – Indirectly controls BP – Body conserves H2O by increasing H2O reabsorption from kidneys – Results in decreased urine output Pituitary Gland: Anterior Lobe • Prolactin – Initiates and maintains breast milk Pituitary Gland: Anterior Lobe • Growth Hormone (somatotrophin) – Stimulates growth – Stimulates repair of tissues and cells – Deficiency = pituitary dwarfism – Over production = gigantism in children and acromegaly in adults Anterior Lobe • 4 Tropic hormones –Stimulate activity of other endocrine glands Tropic Hormones • Thyroid Stimulating Hormone (TSH) – Controls activity of thyroid gland • Adrenocorticotropic Hormone (ACTH) – Controls growth and secretory activity of adrenal cortex Tropic Hormones • Follicle Stimulating Hormone (FSH) – Stimulates egg development in ovaries, secretion of estrogen, and sperm development • Luteinizing Hormone (LH) – Caused ovulation in females and secretion of testosterone in males Pituitary Gland: Middle Lobe • Melanocyte stimulating hormone – Responsible for skin pigment – Albinism – Vitiligo – Patches of melanin form freckles Thyroid Gland • • • • Regulates and controls metabolism Stimulated by TSH Produces T3, T4, & calcitonin Must have iodine Thyroid Hormone (T3 & T4) • • • • • Regulate rate cellular metabolism hormone = metabolism Must have iodine levothyroxine/Synthroid liothyronine/Cytomel Iodine • Basic component of thyroid hormone • Deficiency – Hypothyroidism – Goiter • Sources – Iodine enriched salt – Seafood Parathyroid Glands Calcitonin • Regulates calcium and phosphate • Blocks resorption of calcium and phosphate by bones • Release stimulated by hypercalcemia Parathyroid Glands • Secrete parathyroid hormone (PTH) • Regulates calcium and phosphorus • Appropriate amounts required for: normal nerve and muscle function - blood clotting • Ca+ and phosphorus have inverse relationship Parathyroid Hormone • Increases resorption of Ca+ and phosphate from bones • Increases absorption of Ca+ and phosphorus from food • Activates Vit D • Increases reabsorption of Ca+ by kidneys • Increases excretion of phosphate by kidneys Adrenal Glands Adrenal Glands • 2 portions – Medulla (middle portion) – Cortex (outer portion) Adrenal Cortex • Stimulated by ACTH • Produces steroids – Glucocorticosteroids – Mineralocorticosteroids – Androgens Adrenal Cortex • Glucocorticosteroids – Cortisol • Reduce inflammation – Blocks histamine – Kills T- cells • Promote glucose production – Increases blood glucose – Increased secretion in times of stress Adrenal Cortex Mineralocorticosteroids – Aldosterone • Target organ is kidney • Regulate water and salt balance • Involved in acid/base balance Adrenal Cortex • Androgens – Sex hormones • Small amounts of testosterone and estrogen Adrenal Medulla • Emergency gland • Part of sympathetic nervous system • Produces 2 neurohormones – Epinephrine – Norepinephrine Ovaries and Testicles • Sex glands • Important in development of secondary sex characteristics • Testicles produce testosterone • Ovaries produce estrogen and progesterone. Pancreas Pancreas •Secretes •Glucagon •Insulin Glucagon • Stimulates breakdown of glycogen and release of glucose from liver • Causes increased serum glucose Insulin • Metabolism of blood glucose • Maintenance of proper serum glucose levels • serum glucose = insulin production • serum glucose = insulin production Functions of Insulin • • • • • • Allows glucose into cells Allows glucose to enter liver Stores excess calories/glucose as fat Prevents fat breakdown Normal serum glucose: 70 to 110 mg/dl After meals may reach 140 to 150mg/dl • http://www.youtube.com/watch?v=NazZCu1l wOE&feature=related Factors Affecting Serum Glucose • Raises – Food – Stress – Illness – Growth – Medications – Menstrual cycle • Lowers – Insulin – Oral Diabetic Drugs – Exercise Assessment of Endocrine System • Health History • Inspection • Palpation Diagnostic Testing • Serum hormone levels – Stimulation tests – Suppression tests • • • • • Urine tests Nuclear scanning Radiographic testing Ultrasound Biopsy Endocrine Disorders • Disorders of Pituitary Gland – Diabetes Insipidus – Syndrome of Inappropriate Antidiuretic Hormone • Disorders of Thyroid Gland – Goiter – Hyperthyroidism – Hypothyroidism • Disorders of Parathyroid Gland – Hyperparathyroidism – Hypoparathyroidism Endocrine Disorders • Disorders of Adrenal Gland – Addison’s Disease – Cushing’s Disease – Cushing’s Syndrome • Disorders of Pancreas – Diabetes Mellitus Diabetes Mellitus • Chronic illness in which body lacks insulin, is unable to use insulin, or a combination of both • Body may also have difficulty using fats and proteins • Causes build up of glucose in blood Classifications of Diabetes Mellitus • Prediabetes • Gestational Diabetes (GDM) • Type I = absolute insulin deficiency – Insulin Dependent DM (IDDM) • Type II = insulin resistance – Non-Insulin Dependent DM (NIDDM) Type I Diabetes http://www.youtube.com/watch?v=OYvav8aDGCc Type II Diabetes http://www.youtube.com/watch?v=V LiTbb6MaEU&feature=related Causes of Diabetes • Type I = body kills beta cells • Type II = body cannot use insulin = INSULIN RESISTANCE Who Will Get Which Type? • Type I – – – – Seen in children and young adults Family history (Genetic element) Autoimmune disease Triggered by exposure to virus • Type II – – – – Seen in people over 40 Strong family history Often over-weight Race/Ethnic group is a factor Diagnostic Studies for Diabetes • • • • • • Fasting Blood Sugar (FBS) Random glucose Urine analysis Glucose Tolerance Test Glycohemoglobin (HbA1c) eAG HbA1c Red Blood Cells hemoglobin Glucose Glycohemoglobin HbA1c % Compared with eAG mg/dL A1C % eAG mg/dL 6 126 6.5 140 7 154 7.5 159 8 183 8.5 197 9 212 9.5 226 10 240 Criteria for Diagnosis • FBS – after 4 hours of fasting, BG > 126 mg/dl on 2 separate occasions • Random glucose > 200 mg/dl with symptoms • Elevated HbA1c Scope of Problem • Affects millions of Americans • Affects multiple body systems • Causes both acute and chronic health problems • Older individual gets greater their risk of developing Type II Type I: Symptoms • • • • • • • Polyuria Polydipsia Polyphagia Weight loss Fatigue Glucosuria Blurred vision Type I: Treatment • • • • Insulin Diet Activity/Exercise Glucose Monitoring Insulin • Cannot be taken orally • Must be taken daily or more often • Sources: – Pure pork – Human* – Beef/pork mixed *Most often prescribed (less allergic reactions)* Insulin Types of Insulin Rapid-acting Novolog (aspart) Humalog (lispro Apidra (glulisine) Short-acting Humulin R (Regular) Novolin R (Regular) Intermediate-acting Humulin N (NPH) Novolin N (NPH) Long-acting Levemir (determir) Lantus (glargine) Insulin • Brand names (Humulin and Novolin) specify this is a human insulin • Brand names like Iletin Pork specify this is pork insulin • Humulin R = regular human insulin • Combining types allows better control DRUG EFFECT Insulin: NPH and Regular TIME DRUG EFFECT Insulin: Lantis and Novolog TIME Insulin Sliding Scales Blood Glucose Units to be Administered < 120 0 units 121 – 150 1 unit 151 – 180 2 units 181 – 200 3 units 201 - 230 4 units Why So Many Different Types? • Allows care provider to chose insulin program that works best for client R/T – Eating habits – Willingness to monitor BG levels – Willingness to take multiple injections – Work and activity schedule