Essentials of Human Diseases and Conditions 4 th edition

1. Essentials of Human Diseases and Conditions 4th edition Margaret Schell Frazier Jeanette Wist Drzymkowski

2. Chapter 4Diseases and Conditions of the Endocrine System

3. Learning Objectives • List the major glands of the endocrine system. • Describe the importance of hormones and explain some of the critical body functions that they control. • Explain the importance of normal pituitary function. • Compare gigantism to acromegaly.

4. Learning Objectives (cont’d.) • Describe the condition of dwarfism and its etiology. • Explain the cause of diabetes insipidus. • Explain the treatment of a simple goiter. • List the signs and symptoms of Graves’ disease. • Distinguish between cretinism and myxedema.

5. Learning Objectives (cont’d.) • Explain the pathogenesis of diabetes mellitus. • Identify the two major types of diabetes mellitus. • Distinguish between diabetic coma and insulin shock. • Explain the medical management of all three types of diabetes mellitus.

6. Learning Objectives (cont’d.) • Explain why hypoglycemia can be a serious medical condition. • Compare the signs and symptoms of thyroid hypofunction with those of thyroid hyperfunction. • Describe the signs and symptoms of thyroid malignancy. Discuss the most important prognostic factor.

7. Chapter 4Lesson 4.1

8. The Endocrine System • uses powerful chemical messengers called hormones to: • maintain homeostasis • respond to stress • regulate essential functions • control metabolic rate • direct growth and development

9. Major glands of the endocrine system are: • pituitary • thyroid • parathyroid • adrenal • pancreas • ovaries/testes • pineal • thymus

10. Major Glands of Normal Endocrine System

11. Hormones are chemical messengers that: • are either amino acids (proteins) or steroids • are secreted into the bloodstream by specialized glands • target their actions to very specific tissue receptor sites

12. Important hormones include: • insulin and glucagon • estrogen, progesterone, and testosterone • thyroxine, calcitonin, and thyroid stimulating hormone (TSH) • vasopressin • cortisol and cortisone • aldosterone • growth hormone (GH) • follicle stimulating hormone (FSH) and luteinizing hormone (LH)

13. Hypothalamus-Pituitary-Thyroid Gland Feedback Mechanism

14. Negative Feedback • Hormonal secretions typically regulated by negative feedback; information about the hormone level or its effect is fed back to the gland, which then responds accordingly

15. The effect of pituitary hormones on target tissues

16. Pituitary Gland Diseases Hyperpituitarism: Chronic, progressive disease caused by excessive production and secretion of pituitary hormones, especially growth hormone (HGH)

17. Types of Hyperpituitarism • Gigantism: increased growth hormone — occurs prior to puberty • Treatment focuses on reducing secreted hGH through radiation or surgical intervention to reduce pituitary size • Acromegaly: increased growth hormone — occurs after puberty is complete • Treatment focuses on reversing or preventing tumor mass effects and reducing secreted GH ideally through surgery with or without radiation to the pituitary gland.

18. Hypopituitarism • A deficiency or absence of the hormones produced by the pituitary gland, especially those of the anterior pituitary. • The cause of hypopituitarism may be a tumor or the pituitary or hypothalamus. Headache and blindness may be symptoms of tumor compression of the adjacent optic nerve. • Cause of panhypopituitarism is sometimes unknown; it is more common in women. • Treatment, based on patient age, severity and type, and underlying cause, includes removal of tumor and hormone replacement therapy.

19. Example of Hypopituitarism Dwarfism: abnormal underdevelopment that occurs in children due to decreased growth hormone production Treatment • Somatotropin (hGH) administration • Replacement of thyroid and adrenal hormones • Sex hormones as puberty approaches as necessary

20. Diabetes Insipidus • A deficiency in the release of vasopressin (ADH) from the posterior pituitary resulting in excessive (polyuria) urine excretion and thirst (polydipsia) • Treatment consists of vasopressin injections, nasal spray or oral desmopressin acetate.

21. Thyroid Gland Diseases • A group of disorders caused by increased or decreased amounts of thyroid hormones: • Simple goiter • Hashimoto disease • Hyperthyroidism/Graves’ disease • Hypothyroidism • myxedema

22. Hypofunction bradycardia constipation weight gain reduced alertness fatigue edema/bloating poor circulation cold intolerance dry skin and hair Hyperfunction tachycardia/palpitations diarrhea weight loss anxiety/restlessness fatigue appetite sweating heat intolerance hair loss Thyroid Gland Diseases Symptoms

23. Simple Goiter Enlargement of the thyroid gland: usually palpable results from shortage of dietary iodine • Symptoms include swollen mass (goiter) at anterior aspect of neck, and dyspnea and difficulty swallowing with further enlargement of goiter. • Treatment includes one drop per week of potassium iodide

24. Thyroid Gland Diseases: Hyperthyroidism Graves’ disease: diffuse goiter and over-production of thyroid hormone that can result in life-threatening condition • Causes of Graves’ disease are unknown but it is thought to be autoimmune in nature and there is a strong familial predisposition for it. • Exophthalmos, the outward protrusion of the eyeball, can be present with Graves’ disease. Other symptoms include rapid heartbeat, insomnia, and weightloss, to name a few. • Treatment goal is to reduce thyroid hormone through antithyroid drugs and beta-blockers, or for severe cases, radioactive iodine or surgery.

25. Thyroid Gland Diseases: Hypothyroidism Cretinism: a congenital condition in children in which the thyroid gland is absent or nonfunctional resulting in mental or growth retardation • Treated with thyroid hormone throughout life Myxedema: severe condition that develops in older child or adult; can result in life-threatening symptoms including myxedema coma • Symptoms include slowed metabolism, menorrhagia, weight gain, muscular weakness, and tiredness amongst others • Treatment includes administration of levothyroxine sodium

26. Thyroid Gland Diseases: Thyroid Cancer • Painless lump or nodule on the thyroid gland that is malignant. • Treatment is usually surgery to remove the thyroid gland and any involved lymph nodes and replacement hormone. • Anaplastic types may only be treated with radiation and chemotherapy to prolong survival.

27. Parathyroid Gland Disease • Hyperparathyroidism • overproduction of PTH hormone, resulting in demineralization of bone and release of excess calcium • symptoms include muscle atrophy, GI pain, and nausea amongst others • treatment is highly individualized based on cause • Hypoparathyroidism • reduced production of PTH hormone, resulting in excessive calcium deposits in tissue and decreased circulating calcium • treated with calcium replacement therapy with vitamin D (life-threatening is treated with calcium gluconate IV)

28. Adrenal Gland Diseases • Cushing Syndrome • increase in adrenal cortex secretion of cortisol • early signs and symptoms include weight gain, hypertension, and emotional instability • other signs and symptoms: fatigue, muscle weakness, change in body fat distribution, moon face, fluid retention, edema, excessive hair growth, fertility changes • treatment depends on cause: surgical removal or radiation of tumor or adrenal gland; drug therapy to suppress ACTH

29. Adrenal Gland Diseases (cont’d.) • Addison Disease • partial or complete failure of adrenocortical function • onset usually gradual over weeks to months • fatigue, weakness, gastrointestinal disturbances, weight loss, fluid and electrolyte imbalances, cardiovascular problems, depression, anxiety, “bronzing” of skin tone • treatment includes replacement of natural hormones; increased fluid intake; control of salt and potassium intake; and high carbohydrate/protein diet

30. Endocrine Dysfunction of Pancreas • Diabetes Mellitus • little or no insulin production in the pancreas • transport of glucose to cells is impaired • cells begin to use fats and proteins as energy alternative • blood glucose levels continue to increase, resulting in state of hyperglycemia • signs and symptoms include frequent thirst, urination, weight loss, fatigue, increased appetite

31. Endocrine Dysfunction of Pancreas (cont’d.) • Diabetes Mellitus • Type 1: early, abrupt onset before age 30 with little or no insulin secreted • Type 2: more common form with gradual onset after age 30, especially after age 55, with some pancreatic function intact

32. Warning Signs and Interventions for Diabetic Coma and Insulin Reaction

33. Endocrine Dysfunction of Pancreas (cont’d.) • Diabetes mellitus treatment • Goal is to normalize blood glucose levels and minimize complications through: • diet control • exercise • frequent blood and urine testing • insulin injections or oral hypoglycemics • weight loss (if overweight) • preventive health care

34. Endocrine Dysfunction of Pancreas (cont’d.) • Gestational diabetes mellitus (GDM) • Type 3: decreased ability to metabolize glucose during pregnancy with onset around 24-28 weeks of gestation; the condition usually disappears right after delivery. • Treatment might include control of diet; limited intake of simple sugars; oral hypoglycemic agents; insulin

35. Endocrine Dysfunction of Pancreas (cont’d.) • Hypoglycemia • abnormally low blood glucose level that can be caused by excessive insulin secretion in the pancreas, fasting, or medications • signs and symptoms: sweating, nervousness, hunger, weakness, dizziness, headache, palpitations, confusion, visual disturbances • if severe or untreated, can cause seizures, stupor, coma, and death • Treatment: acute requires intravenous infusion of glucose; hormone glucagon; complex carbohydrate/protein snack with stabilization

36. Precocious Puberty • For boys, puberty that begins before age 9 • For girls, puberty that begins before age 8 • Causes include tumors of the testes/ovaries, hypothalamic or pituitary dysfunction or tumors, and ingestion of hormones or sex steroids • Treatment depends on cause: no treatment if idiopathic; hormone therapy to suppress sexual maturation until appropriate time; treatment more invasive if cause is testicular or brain tumor