Endocrinenotes Part 1 - FILL IN THE BLANK ENDOCRINE SYSTEM DISORDERS STUDY GUIDE PDF

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FILL IN THE BLANK ENDOCRINE SYSTEM DISORDERS STUDY GUIDE...

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Endocrine System Overview of Endocrine System Composed of cells and organs that manufacture and secrete ____________________ It is a system of communication that controls many life-long bodily responses and functions. 3 Parts – relay information and instructions throughout the body Glands Hormones Target cells A Communication Network The endocrine system responds to stimuli by ________________hormones (the chemical messengers that carry instructions to target cells throughout the body) from endocrine glands The target cells read and follow the hormone’s instructions, sometimes building a protein or releasing another hormone Hormones regulate four major body functions: Reproduction Growth and development Homeostasis Metabolism Mechanisms of Hormonal Regulation All hormones share certain general characteristics: Rates and patterns Operate within a feedback system Affect target cells with specific receptors and then act to initiate specific cell functions or activities (they respond only to those hormones for which they have receptors) Excreted by kidneys or deactivated by the liver or cellular mechanisms Negative Feedback In the endrocrine system, negative feedback occurs because the rising hormone levels negates the initiating change that triggered the release of the hormone

3 Categories of Endocrine Disease 1. Hyposecretion: gland releases an inadequate amount of hormone to meet physiologic needs 2. Hypersecretion: increased secretion 3. Hyporesponsiveness of the target organ will cause the same set of clinical symptoms as_______________ usually caused by deficiency of receptors Causes of Altered Function Hyposecretion Congenital Absence of enzyme needed for synthesis Disruption of blood flow Infection, inflammation, immune response Neoplasms

Hypersecretion Excessive stimulation Hyperplasia of the gland Hormone producing tumor of the gland

Hypothalamus & Pituitary Gland Regulates hormone secretion from all major endocrine organs except the pancreas and parathyroid glands ___________________ is the primary organ of the body concerned with maintaining homeostasis; that is, keeping the body’s internal environment constant. Sends several hormones to anterior or posterior pituitary gland Hypothalamus Pituitary Axis

Posterior Pituitary Nerve cell bodies of the hypothalamus synthesize two hormones: __________and Oxytocin. These hormones are produced in the _________________ and stored in the posterior pituitary until stimulated Oxytocin protein hormone stored and released from the posterior pituitary little effect in non-pregnant women increases intensity of labor - stimulates contraction of uterine smooth muscle ________________, a derivative of oxytocin, it is used to initiate and speed labor Also, stimulates contraction of the smooth muscle lining of the milk ducts of the breast, causing letdown of stored milk into nipples ADH Anti-Diuretic Hormone A protein hormone, stored and released from the_______________________. Stimulus: increased plasma osmolality (concentration of solute in circulating blood) is sensed by osmoreceptors in the hypothalamus which then stimulates ADH release. Does ADH make you retain or diurese? What do you retain?

ADH aids in the control of blood volume by acting on the kidneys to __________more water back in the blood ADH is also referred to as __________________because of its ability to cause vasoconstriction if plasma levels are extremely elevated

Diseases of Posterior Pituitary Too Much or Too Little ADH secretion Too Much Syndrome of Inappropriate ADH secretion (________) – high levels of ______ without normal physiologic stimuli for its release Too Little Diabetes Insipidus (__) –_______________of ADH

Syndrome of Inappropriate ADH – SIADH ________________________ High levels of ADH, released continuously (with no feedback control) result in __________ triggered by stimuli other than increased osmolarity and decreased ECF volume. Caused by tumors of the CNS, certain drugs, cancers, common with critical illness, and surgery. SIADH is characterized by: ____________________- excessive water is reabsorbed by distal convoluted tubule and collecting ducts. ADH secretion increases the amount of water reabsorption from the kidneys. Characterized by: Increased or Decreased urine output? Urine hyperosmolarity (hi specific gravity) Concentrated or Dilute? s/s of hypervolemia Serum and Extracellular fluid volume expands and dilutional hyponatremia develops Serum osmolality is low. The blood is ___________ Cells swell, effects of cellular swelling on neurons can be profound (confusion, seizures, coma) Manifestations of SIADH Serum hypo-osmolality and hyponatremia Na+ < 130: thirst, impaired taste, anorexia, fatigue, dulled sensorium Where’s the water? Doesn’t Na+ follow water? Urine hyperosmolality High specific gravity Improvement of hyponatremia with water restriction Hypervolemia triggers what compensatory mechanism? Does this help? SIADH Treatment _____________________ Main treatment Diuretics

↑ free water clearance Hypertonic IV saline solution To correct hyponatremia Usually resolves in 2-3 days In SIADH the client is retaining _____________ because they have too much ____________ Their urine is concentrated or dilute? Their blood is concentrated or dilute?

Diabetes Insipidus __________________ of ADH or lack of renal response to ADH causes excessive loss of __________ and results in a disorder call Diabetes Insipidus , (DI) Caused by injury to pituitary gland, brain tumors, damage to renal tubular cells, pharmacologic agents. THINK: Diuresis! DI characterized by: (similar to dehydration) Polyuria (15 L in 24 hours) excretion of large volumes of dilute urine What am I worried about? Polydipsia (excessive thirst) Nocturia Low specific gravity of urine. Urine is _________ Hypernatremia - high serum osmolarity. Blood is ____________ Did Na+ follow water? Neurological symptoms are thought to be due to shrinkage and dehydration of cells. DI Treatment Drug therapy Vasopressin preparations DOC –____________ (Desmopressin) Administered twice daily as a nasal spray Also indicated for childhood enuresis Correct dehydration. How? Prevent clots At risk d/t dehydration of the intravascular compartment Vasopressin Antidiuretic hormone preparation Used to normalize urinary water excretion in patients with DI (tx is lifelong) Monitor fluid and electrolytes Monitor for water intoxication: Drowsiness Listlessness H/A

Use caution in patients with CAD or PVD because it is a powerful_________________ Nursing Implications If patient inadvertently takes too much drug, assess for s/s of water intoxication: drowsiness, listlessness, and headache Assess for vasoconstrictive effects: angina, hypertension, gangrene of extremities Assess compliance - life long administration: delivered by nasal spray. Tablet for enuresis Monitor I and O, daily weight

Anterior Pituitary Anatomically separate from the hypothalamus, but functionally connected to it via its blood supply In response to hormone activation from hypothalamus, anterior pituitary will secrete various hormones Anterior pituitary is a major target organ for hypothalamus hormones with release of its _______ hormones Hormones produced include: Somatotropic hormones Growth hormone Prolactin Thyroid stimulating hormone (TSH) Thyrotropin controls the release of thyroid hormone from the thyroid gland Adrenocorticotropin (ACTH) hormone Controls the release of cortisol from the adrenal gland Follicle stimulating hormone (FSH) and Lutenizing hormone (LH) Growth hormone Also called ___________________ Released from the anterior pituitary in response to growth-hormone releasing factor (GHRF) from the hypothalamus Acts directly on most body tissues, promoting protein deposits that are essential for growth Increases the mobilization of fatty acids Decreases glucose utilization (insulin resistance is increased) Will blood sugar increase or decrease? No specific target organ Deficiency of Growth Hormone Caused by decreased secretion of GhRF or GH, tumors, radiation, trauma Impairs normal growth and development in infants, children and adolescents (when GH is normally secreted in higher amounts). Treated with synthetic GH subcutaneously 3 to 7 days a week. Prior to closure of ______________ Goal: improved growth velocity and attainment of an adult height that is normal for the individual’s genetic background. Sermorelin Synthetic growth hormone-releasing factor Acts like natural GhRH: acts on the anterior pituitary to stimulate release of GH Use for treatment in GH deficiency in children to normalize growth and development

Contraindicated after epiphyseal closure Must have a functioning pituitary. Why? Monitor height/weight

Growth Hormone Excess Almost all cases caused by pituitary adenomas 2 Types _______________– before puberty If occurs before puberty, causes bones to grow large - reach 7 to 9 feet tall Gigantism _________________– after puberty Usually occurring in 4th or 5th decade of life. ____________________________________ = Acromegaly (Greek for large extremities) ↑ bone density and width of bones enlarge: lower jaw, hands, face, and feet Has a diabetogenic effect: The increase in mobilization of fatty acids predisposes to ketoacidosis and the decrease in the utilization of glucose tends to _________blood sugar. Manifestations of Acromegaly Enlarged tongue Interstitial edema Coarse skin and body hair Enlargement facial bones, hands, feet Profusion of the jaw and forehead Barrel chest with arthralgia and arthritis Nerve damage: weakness, muscular atrophy, footdrop, and sensory changes Hypertension, left heart failure, CNS disturbances Enlarged & overactive sebaceous and sweat glands Impaired glucose tolerance Treatment: Acromegaly Remove Adenoma Resection of Anterior Pituitary tumor Possible radiation therapy Pharmocologic Octreotide (Sandostatin) Synthetic Somatostatin used to ___________ Growth Hormone Release

Thyroid Hormone The thyroid produces 3 hormones: T3, T4, and Calcitonin The principal hormones produced are Triiodothyronine (T3) Thyroxine (T4) Many tissues in the body _______________T4 to T3. T3 is the more active form of thyroid

hormone. We need an adequate supply of iodine in our diet for thyroid hormone to be produced because the thyroid gland takes iodine from the blood to make thyroid hormones Thyroid stimulating hormone (TSH) and thyroid hormone Thyrotropin-releasing hormone (TRH) When thyroid hormone levels get low, TRH is released from the hypothalamus. TRH Stimulates thyroid-stimulating hormone (TSH) release from the anterior pituitary. For TSH, the target organ is the thyroid gland which secretes thyroid hormones. TSH stimulates all aspects of thyroid function, including release of T3 and T4 Works on a negative feedback system. T3 and T4 act on the pituitary to suppress further TSH release and inhibit TRH

Function of Thyroid Hormones Important in the regulation of: __________ synthesis basal metabolic rate (BMR), which is the rate of heat production and energy expenditure in the body gluconeogenesis and cellular uptake of ___________ the force and rate of cardiac contractions normal development of CNS the responsiveness of target cells (beta-receptors) to catecholamines, thus increasing heart rate and causing heightened emotional responsiveness

Goiter Enlarged thyroid glands Appears in both _______ or _______________________of the thyroid The gland enlarges in an attempt to produce sufficient amounts of thyroid hormones or in response to overproduction of hormones Goiter can be due to other causes: one cause is iodine deficiency in diet Influence of iodine Low iodine: when iodine availability is low, production of thyroid hormones _________. This promotes the release of TSH which causes thyroid size to increase (goiter) High iodine: when iodine levels are high, uptake of iodine is suppressed and synthesis and release of thyroid hormones decline Thyroid function tests (TFT’s) Serum T4 testmeasures total (bound plus free) thyroxine reflects overall thyroid activity used for initial screening of thyroid function T4 ____in hypothyroid (primary) T4 ____in hyperthyroid Serum T3 test

Measures total (bound plus free) triiodothyronine Useful in diagnosing hyperthyroidism Serum TSH Most sensitive test for diagnosis of hypothyroidism because small reductions in T3 and T4 cause dramatic ____________in TSH Hypothyroidism Most common thyroid disorder Results from decreased levels of circulating thyroid hormone Caused by: autoimmune diseases (Hashimoto’s), most common insufficient iodine in the diet surgical removal of the thyroid destruction of the thyroid by radiation neoplasms severe trauma Infections congenital Hypothyroidism - Classification Primary Results from pathologic process that ______________thyroid gland (high TSH, low thyroid hormone) Secondary Caused by deficiency of pituitary TSH secretion (low TSH, low thyroid hormone) May be med induced: Iodide, PTU Sulfonamides, Amiodarone, Inteluekin 2, Interferon alpla Congenital hypothyroidism If deficiency occurs during embryonic and neonatal life, called Cretinism (causes mental retardation and derangement of growth) What’s the baby going to look like? How’s it going to act? Hypothyroidism results in a general slowing down of body processes - decrease in BMR Everything _______________! Hypothyroidism :Occurs insidiously-affecting all systems: ______________BMR-results in a general slowing down of body processes (cold, dry skin) weight gain Lowers heat production cold intolerance, lethargy, fatigue. Mentality may be impaired. Goiter if reduced levels of T3 and T4 promote excessive release of TSH _________________-altered composition of dermis and separation of connective fibers Nonpitting, boggy edema around eyes, hands,feet Thickened tongue hoarseness, slurred speech Hypothyroidism - Diagnosis Decreased levels of T3 and T4

Serum TSH may be high or low Everything goes down except weight increases – why?

Myxedema Coma Myxedema coma is a medical emergency: a ___________level of consciousness associated with severe__________________. S&S include: hypothermia hypoventilation hypotension bradycardia Pharmacologic Treatment Thyroid deficiency - treat with hormone replacement therapy Synthetic Thyroxine (T4): Levothyroxine (_____________) is DOC Usual dose: 100-150mcg/day for life Increases levels of T3 and T4 because most T4 is converted to T3 Also used for simple goiter and Hashimoto’s Disease Other Pharmacologic options: Liothyronine (Cytomel) Synthetic _______ Not recommended for long-term use Liotrix (Thyrolar) _________________of Levothyroxine and Liothyronine No advantage over Levothyroxine Thyroid Replacement: Nursing Implications Adverse reactions are rare if dose is appropriate Use caution if patient has C/V disease – hormone can increase responsiveness to catecholamines and sympathetic stimulation So what can occur? If dosage is excessive or if you have a decrease in excretion, thyrotoxicosis and thyroid storm may occur Treatment …………______________! Teach S/S of thyrotoxicosis and not to d/c abruptly

Hyperthyroidism

______________thyroid hormone Diagnosis: excessive levels of circulating TSH Caused by: Dysfunction of the thyroid gland, the pituitary, or the hypothalamus (Overactive) Excessive intake of thyroid hormones Hyperthyroidism or Thyrotoxicosis Causes: Graves disease (more common) Autoimmune dx. Exopthalmus Toxic nodular goiter Plummers dx Graves Disease ___________________disease in which developed antibodies stimulate TSH production and inappropriately activate production of thyroid hormones (T3 & T4) Symptoms: Adrenergic stimulation- BMR Tachycardia and palpitations Heat intolerance-excessive sweating Nervousness Thin hair and skin Tremor Large and protruding eyeballs-exophthalmos Weight loss with hunger Diffuse thyroid enlargement (goiter), may auscultate bruit Because increased amounts of thyroid hormones reach the cells, all metabolic activities are______________; the BMR rises, energy expenditure is increased, and heat production rises Everything goes up except weight decreases – why?

Thyrotoxic Crisis Also called ___________________ Life-threatening complication sudden increase in thyroid hormone levels uncontrolled fever - 100 to 106 degrees significant tachycardia, dysrhythmias profuse diaphoresis shock vomiting dehydration CNS: hyperkinesis, anxiety, and confusion

Drug Treatment of Hyperthyroidism Thiomides: PTU, Tapazole Stops the thyroid from making thyroid hormone! Does not destroy existing thyroid stores Overuse converts to hypothyroid state Monitor levels of T4 and T3

Goiter associated with prolonged use PTU is preferred treatment during pregnancy and breast feeding Iodine Compounds Decrease the _______and ____________of the gland Radioactive Iodine (131I) – ______ for Graves Dx Used to destroy thyroid tissue (goal is to avoid destroying too much) Does not affect surrounding tissue Monitor bone marrow Usually 1-3 treatments, full effects may take 2-3 months Contraindicated with pregnancy Lugol’s solution, SSKI (Potassium iodide) – ________________ Used preoperatively to decrease vascularity and decrease bleeding risk Dilute in fruit juice for taste, stains teeth Report symptoms of iodism: brassy taste, mouth burning, sore gum & teeth Report and discontinue if severe abdominal distress develops from toxicity

Beta Blockers Inderal (Propanlol) Beta blockers won’t let you release ____________ Decreases HR and BP Decreases anxiety Slows everything down, you remain calm? Who shouldn’t take Beta Blockers? Thyroidectomy May be partial or complete What will they need to take for life after surgery? Important to teach to take the same time everyday to maintain constant hormone level.

ACTH

Adrenal Glands Located above the kidneys 2 parts: inner medulla (secretes Epi and NE) and outer cortex Adrenal cortex synthesizes three important classes of hormones Glucocorticoids (Cortisol) Mineralocorticoids (primarily aldosterone) Androgens Total loss of adrenal cortical function is fatal in 3 to 10 days if untreated Referred to as the three S’s : Sugar, Salt, Sex More than 30 hormones are produced by the adrenal gland. Of these hormones: Aldosterone is the principal mineralocorticoid – S____ Cortisol (hydrocortisone) the major glucocorticoid – S______ Estrogens and Androgens, the S____ hormones What regulates hormone release? Glucocorticoids are regulated by the hypothalamic-pituitary-adrenal negative feedback Secretion of Aldosterone is regulated by renin-angiotensin mechanism Glucocorticoids Essential for survival __________________ (hydrocortisone) is the major glucocorticoid Major actions: Regulate mood Suppress the immune and inflammatory response Increase breakdown of Protein and Fats Inhibit insulin release Mineralocorticoids Play an essential role in regulating fluid and mineral balance (sodium and potassium) Aldosterone stimulates kidneys to retain ______________and lose _______ Androgens- chief sex hormones

Addison’s Disease Hypofunction of Adrenals Chronic adrenal insufficiency Caused by destruction of ________________ Autoimmune response – most common Deficient cortisol secretion, may have ↓ aldosterone and androgen production Addison’s Disease - Adrenal Insufficiency Clinical manifestations: Not enough aldosterone, will ______Na+ and water and __________K+. Most of the S&S will initially come from HYPERKALEMIA Cortisol insufficiency causes diminished gluconeogenesis, decreased liver glycogen, and increased sensitivity of peripheral tissues to insulin.

Blood sugar is going to go _________ Symptoms are often vague & may not be apparent until 80-90% of the adrenals have been destroyed Commonly complain of: Chronic fatigue, muscle weakness N&V Anorexia and weight loss Occasional acute abdominal distress Salt cravings (dt ↓ aldosterone and resulting hyponatremia) Hypoglycemia Hyperpigmentation With persistent insufficient amts. of cortisol and aldosterone the body becomes: Weak, Dehydrated and unable to maintain BP Treatment – Addison Dx Combat the fluid volume deficit Why...