Nurse 3200: Endocrine/Parathyroid and Adrenal Disorders(Ch 24)

Primary hyperparathyroidism is most commonly caused by ______________. (A) a tumor of the parathyroid glands (B) a tumor of the anterior pituitary (C) elevated serum calcium levels (D) excess adrenocorticotropic hormone secretion (E) kidney failure

(A)

Which of the following would you expect to see in a patient suffering from Addison's disease? (A) Hypoglycemia (B) Elevated serum calcium (C) Elevated norepinephrine (D) Elevated cortisol (E) Elevated blood pressure

(A)

What is another name for Mary's condition (primary adrenal insufficiency)? (A) Addison's disease (B) Cushing's disease (C) Cushing's syndrome

(A) Addison's disease is a form of primary adrenal insufficiency. Remember, in Addison's disease, more adrenal hormones need to be "added." Cushing's disease and Cushing's syndrome are adrenal excess diseases.

Goiter

An enlargement of the thyroid gland with or without symptoms of thyroid dysfunction. Excess pituitary TSH can stimulate enlargement of the thyroid gland and cause ( blank ) formation. Low iodine levels cause low thyroid hormone manufacture, which the pituitary senses and then attempt to compensate for by increasing TSH, which incites ( blank ) formation. Enlargement of the thyroid gland can also occur from goitrogens, which are foods or other substances that promote thyroid gland enlargement.

Treatment of Hyperthyroidism

Antithyroid hormone medication propylthiouracil (PTU) Radioactive iodine* treatment Surgery Replacement thyroid hormone (levothyroxine) is needed for life. * Radioactive iodine is taken up by the gland and suppresses its activity.

Hyperthyroidism Signs & Symptoms

Anxiety Tremor Tachycardia Feeling warm Loss of weight Exophthalmos Atrial fibrillation Decreased fertility

The Endocrine Feedback System

As a result of pituitary stimulus, an endocrine gland secretes a specific hormone. After the hormone is secreted, the pituitary senses the level in the bloodstream. The pituitary interprets the level of hormone as normal, high, or low and then responds by either re-releasing the tropic hormone or ceasing tropic hormone release, thereby maintaining a normal hormone level.

Example of Negative Feedback

As cortisol levels in the bloodstream rise, the pituitary senses the increased level and shuts off the stimulus to the adrenal gland.

Alterations of the Hypothalamic - Pituitary System

Deficiency of hypothalamic hormones. Variety of manifestations can be seen: - in adult women: menses cease - absence of GnRH. - in adult men: spermatogenesis is impaired - absence of GnHRH. - ACTH response to low serum cortisol levels is decreased due to absence of CRH. - Hypothalamic hypothyroidism - Hyperprolacinemia

Posterior Pituitary Hormones

Does not produce its own hormones; it stores hormones. The hypothalamus produces ADH (also referred to as arginine vasopressin [AVP]) and oxytocin (OXT). - These two hormones are released into the hypothalamic-hypophyseal tract to the posterior pituitary, where they are stored. From the posterior pituitary they are released into the circulation when needed.

Endocrine dysfunction can also be referred to as a primary, secondary or tertiary disorder: Tertiary Disorder

Dysfunction caused by a hypothalamic origin.

Endocrine dysfunction can also be referred to as a primary, secondary or tertiary disorder: Secondary Disorder

Dysfunction caused by abnormal pituitary activity.

Endocrine dysfunction can also be referred to as a primary, secondary or tertiary disorder: Primary Disorder

Dysfunction sauces by the endocrine gland itself.

Endocrine System

It is a network of glands and hormones that regulate and control both long and short term biological functions. Together with the nervous system, acts as the body's communication network. It is composed of various endocrine glands and endocrine cells. The glands are capable of synthesizing and releasing special chemical messenger hormones. Maintains homeostasis Controls metabolism Regulates fluid balance Controls growth Controls reproduction Mobilizes stress response

The Pituitary

Known as the "master gland" due to its role in controlling and regulating the other glands of the body.

Diabetes Insipidus Pathophysiology: Neurogenic

Lack of ADH

Diagnosis of Graves' Disease

Low TSH High T3 High T4 Antithyroglobulin Antithyrotropin receptor antibody Ultrasound with color-Doppler evaluation. Radioactive iodine scanning and measurements of iodine uptake. In ( blank ), the radioactive iodine uptake is increased and the uptake is diffusely distributed over the entire gland.

Syndrome of inappropriate ADH secretion (SIADH) Signs & Symptoms

Mental status changes Headache Nausea & vomiting Seizures Coma Cerebral edema Hyponatremia (< 130 mEq/L) High urine osmolarity Low urine output

Diabetes Insipidus (DI) Signs & Symptoms

Mental status changes Weakness Lethargy Seizures Coma Dehydration Polyuria Polydipsia Hypernatremia Low urine osmolarity High urine output Hyperosmolarity (> 320 mOsm/L)

Thyroid Nodule

Most are asymptomatic, but they can cause hypothyroidism or hyperthyroidism. A single ( blank ) is associated with an increased risk of malignancy, whereas multiple nodules are often benign.

In the adult, severe hypothyroidism or hyperthyroidism can cause:

Myxedema, also referred to as pretrial dermopathy, non pitting edema, and thickened leg skin.

Graves' Disease (Hyperthyroidism) Signs & Symptoms

Nervousness Insomnia Sensitivity to heat Weight loss Gland is usually enlarged and palpable. An audible bruit may be heard because of high glandular blood flow. Atrial fibrillation Exophthalmos

Endocrine gland dysfunction can be divided into two categories: Hyperfunction of an endocrine gland:

Occurs when there is an excessive amount of hormone secreted by the gland.

Endocrine gland dysfunction can be divided into two categories: Hypofunction of an endocrine gland:

Occurs when there is an inadequate amount of hormone secreted by the gland.

Thyrotoxic Crisis (Thyroid Storm)

Overwhelming release of thyroid hormones that exerts an intense stimulus on the metabolism. This is a life-threatening condition most commonly precipitated by surgery, trauma, or infection.

Hyperpituitarism

Pituitary adenoma is the most common cause of hyperpituitarism. The adenoma can produce ACTH, TSH, or growth hormone (GH). Prolactinoma is a specific type of pituitary adenoma that produces PRL.

Upregulation and Downregulation of Endocrine Receptors

Pituitary hormones act on receptors located on endocrine glands to secrete hormones. The reactions of the receptors on endocrine glands vary depending on the amount of stimulation by these pituitary hormones.

Sheehan's Syndrome

Pituitary ischemia and infarction that develops after childbirth because of severe hemorrhage. - Hypopituitarism results. Women who suffer from this: - develop deficiency of ACTH, TSH, FSH, LH, ADH, and PRL - results in adrenal insufficiency - hypothyroidism - amenorrhea - diabetes insipidus (DI), and inadequate lactation.

Causes of Hypopituitary Function

Pituitary tumor Complications following brain surgery Radiation of a brain tumor Trauma Ischemia Infarction Hemorrhage Sheehan's Syndrome Empty Sella Syndrome Panhypopituitarism

Syndrome of inappropriate ADH secretion (SIADH): Clinical Presentation/Diagnosis

Plasma osmolality of < 275 Urine Na+ > 20 mEq/L with normal dietary salt intake. Normal thyroid, adrenal, cardiac, liver and kidney function. Clinical euvolemia: - no clinical s/s of volume depletion/excess like (elevated HR, decrease skin turner, dry mucus membranes, edema, or ascites) - No recent use of diuretic agent.

Diabetes Insipidus (DI) vs Diabetes Mellitus (DM)

Polyruia and dehydration occur in both diabetes mellitus and diabetes insipidus. It is important to measure serum glucose to differentiate DM from DI. Serum glucose is elevated in DM, but not in DI.

Hypothyroidism Affect All Body Organs:

Raises cholesterol; hyperlipidemia Raises carotene levels (yellows skin) Causes anemia Decreases filtration by kidney Can cause hoarse voice

Treatment of Hypothyroidism

Replacement hormone therapy with levothyroxine. Surgical intervention if necessary.

The Adrenal Gland Consists of Two Parts: Cortex and Medulla. Cortex

Secretes corticosteroids, also called glucocorticoids (cortisol), androgens (testosterone), and mineralocorticoids (aldosterone)

The Adrenal Gland Consists of Two Parts: Cortex and Medulla. Medulla

Secretes epinephrine and norepinephrine.

Pituitary: Anterior Pituitary

Secretes: - growth hormone (GH) - prolactin (PRL) - adrenocorticotropic hormone (ACTH) - thyroid-stimulating hormone (TSH) - follicle-stimulating hormone (FSH - luteinizing hormone (LH)

Hormones

Substances which are secreted by specialized cells in very low concentrations and they are able to influence secreted cell itself (autocrine influence), adjacent cells (paracrine influence) or remote cells (hormonal influence).

Pituitary Apoplexy

Sudden destruction of the pituitary tissue caused by infarction or hemorrhage into the gland. Traumatic brain injury is the most common cause - but it can occur in patients with DM, pregnancy, sickle cell anemia, anticoagulation, or increased intracranial pressure.

Hyperparathyroidism

Symptoms are caused by excessive secretion of PTH with resulting hypercalcemia and bone breakdown. Muscle weakness Poor concentration Neuropathies Hypertension Kidney stones Metabolic acidosis Osteopenia Pathological fractures Constipation Depression, confusion, or subtle cognitive deficits.

Pituitary: Hypothalamus

Synthesizes: - antidiuretic hormone (ADH) - oxytocin (OXY), which are stored and released by the POSTERIOR PITUITARY.

Example of Endocrine Feedback

The hypothalamus secretes corticotropin-releasing factor (CRF), which stimulates the pituitary gland. The pituitary gland secretes adrenocorticotropic hormone (ACTH), which, in turn, stimulates the adrenal gland to secrete the hormone cortisol.

Pathology of Diabetes Insipitus

The nephron does not perform antidiuresis, meaning that the nephron does not reabsorb water from the tubule fluid. The body loses high amounts of water in the urine, causing polyuria and highly dilute urine. The bloodstream loses water, which concentrates its sodium content, causing hypernatremia and dehydration.

Hypoparathyroidism

The symptoms associated are the result of insufficient PTH secretion and the resultant hypocalcemia. Muscle cramps Irritability Tetany Convulsion * Hypocalcemia causes a carpal spasm known as Trousseau's sign and facial muscle twitch called Chvostek's sign.

Example of Downregulation

When an individual takes an excessive prolonged dose of glucocorticoid drugs (prednisone). The pituitary sense the high blood level of glucocorticoids; as a result, it does not need to secrete natural ACTH. There is no need to stimulate the adrenal gland because natural glucocorticoids are unnecessary; the body is receiving more than enough exogenous glucocorticoids. As a result, the adrenal gland down regulates its receptors and become less sensitive to ACTH stimulation. Adrenal atrophy can occur.

Endocrine Dysfunction

When there is an imbalance of hormones that can cause hyperfunction or hypofunction of the target organs. Can occur at the hypothalamus, pituitary, or endocrine gland itself.

Exophthalmos

Wide-eyed stare associated with increased sympathetic tone and infiltration of the extra ocular area with lymphocytes and mucopolysaccharides. Periorbital edema and bulging of the eyes termed Graves' ophthalmopathy. Women are more often affected with Graves' ophthalmopathy than men.

Hypopituitarism

Also known as pituitary insufficiency, is the hypo-secretion of one or more of the pituitary hormones.

At his follow-up examination, Lee's laboratory values revealed elevated serum PTH, elevated serum calcium, and reduced serum phosphorus. What form of hyperparathyroidism does Lee exhibit? (A) Primary hyperparathyroidism (B) Secondary hyperparathyroidism (C) Tertiary hyperparathyroidism

(A) Primary hyperparathyroidism is a disorder in the parathyroid glands themselves. The laboratory values indicate disruption of normal parathyroid function, as elevated serum calcium usually negatively feedback to the parathyroid glands, suppressing PTH release. In this instance, the parathyroid glands are no longer responding as expected to the calcium signal. Secondary hyperparathyroidism is elevated PTH levels as a result of some other organ, not the parathyroid glands, experiencing dysfunction. For example, if the kidneys are unable to reabsorb calcium, PTH levels remain elevated.

Pheochromocytoma __________________. Select all that apply. (A) is a disorder of the adrenal medulla. (B) results in elevated cortisol levels. (C) mimics Addison's disease. (D) results in reduced norepinephrine levels. (E) may cause elevated heart rate and blood pressure.

(A) (E)

Based on Mary's laboratory results, which form of adrenal insufficiency does Mary have? Low cortisol, low aldosterone, elevated ACTH, low blood glucose, low serum sodium, elevated serum potassium, normal calcium, normal PTH. (A) Primary adrenal insufficiency (B) Secondary adrenal insufficiency (C) Tertiary adrenal insufficiency

(A) Mary's condition is a result of a problem in the adrenal glands not being able to produce cortisol. The adrenal glands are receiving a signal from the anterior pituitary, shown by the elevated ACTH; however, the glands are incapable of responding to this signal. A tertiary condition is a problem in the hypothalamus, and Mary's problem is located within the adrenal glands.

Which of the following conditions do you also suspect Mary may experience? (A) Weight gain (B) Hypotension (C) Diabetes mellitus (D) Insulin resistance (E) Dyspnea

(B) Both aldosterone and cortisol, which are low in Mary, help maintain blood pressure. Without adequate levels of these hormones, a patient may experience hypotension. Aldosterone stimulates sodium and water reabsorption, maintaining blood volume and blood pressure. Cortisol is a vasoconstrictor, which also helps maintain blood pressure.

Mary reports that she is taking no medications. Which medications may cause adrenal insufficiency? (A) NSAID's (B) Corticosteroids (C) Anti-histamines (D) Diuretics (E) Beta-blockers

(B) Corticosteroid usage, especially for longer periods, can suppress normal cortisol production by the adrenal glands. In this case, ACTH levels are also reduced due to the negative feedback by the corticosteroids. The other medications listed do not affect adrenal gland synthesis of cortisol.

What explains Mary's "tan" appearance? (A) Reduced blood glucose activates melanocytes (B) Increased ACTH leads to increased melanocyte-stimulating hormone (MSH) (C) Decreased cortisol stimulates pigment production (D) Reduced aldosterone activates melanocyte-stimulating hormone

(B) In Mary's case, reduced cortisol causes an elevation in ACTH. As precursor molecule for ACTH also contains melanocyte-stimulating hormone (MSH). As more ACTH is formed, so is more MSH, which in turn activates melanocytes leading to a tanned appearance.

Lee, age 45, recently received a phone call from his physician who was concerned about some laboratory values obtained at a recent appointment, specifically extremely elevated serum calcium levels. Which of the following disorders may result in a pronounced elevation in serum calcium? (A) Hypoparathyroidism (B) Hyperparathyroidism (C) Adrenal insufficiency (D) Adrenal excess

(B) Parathyroid hormone, secreted by the parathyroid glands, elevates serum calcium levels. His elevated calcium levels are due to hyperparathyroidism. The adrenal glands do not regulate serum calcium levels.

Which of the following may also result in a "tanned" appearance? (A) Primary adrenal excess (B) Secondary adrenal excess (C) Hypothyroidism (D) Hyperparathyroidism

(B) Secondary adrenal excess refers to a problem in the anterior pituitary, the organ that synthesizes ACTH. In secondary adrenal excess, ACTH is elevated, along with its precursor molecule, which contains melanocyte-stimulating hormone.

Secondary hyperparathyroidism may result from _______________. Select all that apply. (A) a tumor of the anterior pituitary gland. (B) any disorder that causes hypocalcemia. (C) a tumor of the parathyroid gland. (D) suppressed parathyroid hormone secretion. (E) failure of the kidneys to reabsorb calcium.

(B) (E)

Which of the following laboratory values may lead you to believe a patient has Cushing's syndrome? Select all that apply. (A) Elevated adrenocorticotropic hormone (B) Elevated cortisol (C) Elevated norepinephrine (D) Reduced cortisol (E) Reduced adrenocorticotropic hormone

(B) (E)

A disorder of the anterior pituitary resulting in elevated adrenocorticotropic hormone is known as ____________. (A) Cushing's syndrome (B) Addison's disease (C) Cushing's disease (D) pheochromocytoma (E) acromegaly

(C)

What factor is likely playing a role in Mary's abnormal serum sodium and potassium levels? (A) Elevated ACTH (B) Reduced cortisol (C) Reduced aldosterone (D) Normal PTH

(C) Aldosterone is released from the adrenal cortex and targets the kidneys. Aldosterone stimulates sodium reabsorption and potassium secretion by the kidneys. Without adequate aldosterone, sodium is excreted in the urine, while potassium is reabsorbed.

A patient was recently admitted with primary hyperparathyroidism. Which of the following laboratory values would you expect to see? Select all that apply. (A) Decreased parathyroid hormone (B) Increased serum calcium (C) Increased parathyroid hormone (D) Increased serum phosphate (E) Decreased serum calcium

(C) (E)

Destruction or removal of the parathyroid glands will cause _________________. (A) primary hyperparathyroidism (B) pheochromocytoma (C) secondary hypoparathyroidism (D) primary hypoparathyroidism (E) Cushing's disease

(D)

Had Lee been experiencing primary hypothyroidism, instead of primary hyperparathyroidism, what laboratory results would you expect? (A) Elevated PTH, elevated calcium, elevated phosphorus (B) Elevated PTH, reduced calcium, elevated phosphorus (C) Reduced PTH, elevated calcium, elevated phosphorus (D) Reduced PTH, reduced calcium, elevated phosphorus

(D) Hypoparathyroidism indicates reduced, not elevated, PTH levels. As PTH increases serum calcium levels, a reduction in PTH results in lower than normal calcium levels. Phosphorus levels are often opposite calcium levels. As calcium levels decline, phosphorus levels increase.

Mary presents in your office with the unusual complaint of being "more tan" than expected based on her self-report sun exposure. Follow up questions reveal that Mary has been experiencing severe fatigue, dizziness upon standing, and an overall feeling that "something is wrong." You examine Mary and order blood tests. The test results show the following abnormalities: low cortisol, low aldosterone, elevated ACTH, low blood glucose, low serum sodium, elevated serum potassium, normal calcium, normal PTH. Mary is taking no medications. Which of the following conditions is most likely based on Mary's laboratory results? (A) Primary hyperparathyroidism (B) Adrenal excess (C) Secondary hyperparathyroidism (D) Adrenal insufficiency (E) Primary hypoparathyroidism

(D) Mary's laboratory results indicate normal PTH and calcium levels, so issues with the parathyroid gland can be ruled out. Low cortisol and elevated ACTH levels are associated with adrenal insufficiency. Elevated cortisol is a sign of adrenal excess.

Which of the following most likely causes Mary's low blood glucose? (A) Reduced aldosterone (B) Elevated ACTH (C) Low serum sodium (D) Low cortisol (E) Increased serum potassium

(D) Cortisol is a glucose-sparing hormone, meaning it works to keep blood glucose levels elevated. With inadequate cortisol, blood glucose levels may fall. Neither aldosterone nor ACTH directly affect blood glucose levels.

In Cushing's syndrome, a ____________ adrenal gland causes elevated levels of _____________. (A) hypoactive; adrenocorticotropic hormone (B) hyperactive; adrenocorticotropic hormone (C) hypoactive; cortisol (D) hyperactive; norepinephrine (E) hyperactive; cortisol

(E)

To determine if a patient is suffering from pheochromocytoma, which laboratory values would you examine? (A) Cortisol (B) Parathyroid hormone (C) Aldosterone (D) Adrenocorticotropic hormone (E) Norepinephrine

(E)

Classic hormones are divided into three groups:

- Low Molecular (Amine) Hormones: ( catecholamines, thyroid hormones, prostaglandins, leucotrienes, dopamine, serotonine, GABA, melatonin...) - Steroid Hormones: ( gluco- and mineralocorticoids) - Polypeptidic and Protein Hormones: ( insulin, leptin...)

Syndrome of inappropriate ADH secretion (SIADH) characteristics:

- hyponatremia - hyp-osmolality of the blood r/t excessive ADH secretion - concentrated urine

Thyroid

A butterfly-shaped gland located in the neck that secretes triiodothyronine (T3) and thyroxine (T4). Thyroxine is the regulator of body metabolism that influences almost every body system. Iodine is a necessary component in the synthesis of thyroid hormone. Thyroid problems are more likely in women than men.

Empty Sella Syndrome

A condition caused by compression of the pituitary gland by brain tissue herniation, is also a cause of hypopituitarism. Occurs when the meningeal membrane that surrounds the brain herniates into the sella turcica, a bony area where the pituitary gland sits int he brain. The herniation of this membrane flattens the pituitary against bone and pituitary insufficiency results. Can be caused by increased intracranial pressure, radiation, or trauma.

Diabetes Insipitus (DI)

A condition resulting from too little ADH (category 1) Nephrogenic DI = when kidney fails to respond to ADH )category 2) Refers to Polyuria. Causes EXCESSIVE amounts of very dilute, but otherwise normal urine.

Panhypopituitarism

A rare disorder, is the complete loss of all the pituitary hormones.

Hypothalamic Hypothyroidism

Absence of GH regulatory hormones.

Treatment of Diabetes Insipidus (DI)

Administration of ADH. Surgical treatment of some pituitary causes of ( blank ) may be required. Supportive treatment measures and the use of non steroidal anti-inflammatory agents (NSAIDs) are used for the patient with nephrogenic ( blank ). IV hypotonic solutions (0.45% saline) to replace urine output. Desmopressin is the drug of choice.

Adrenal Insufficiency: Addison's Disease

Adrenal insufficiency is most commonly caused by autoimmune destruction of the adrenal gland. SYMPTOMS: weakness hypotension easy fatigue inability to concentrate emotional lability anorexia nausea vomiting hypoglycemia electrolyte imbalances bronze pigmentation of skin changes in distribution of body hair In women, there is loss go pubic and axillary hair and amenorrhea.

Characteristics Associated with Malignant Thyroid Nodule

Age younger than 20 years or older than 70 years. Male sex Associated symptoms of dysphagia or dysphonia History of neck irradiation Firm, hard, or immobile nodule Presence of cervical lymphadenopathy

Central Diabetes Insipitus (DI)

Cause in adults is typically damage to pituitary gland or hypothalamus. - Idiopathic (30%) - Malignant or benign tumors of the brain or pituitary gland (25%) - Cranial surgery (20%) - Head trauma (16%)

Hyperprolacinemia

Caused by an absence of unusual inhibitory controls of prolactin secretion.

Excessive Growth Hormone of Hyperpituitarism

Children: gigantism: greater than 7ft tall, large hands and feet, coarse facial features, hypogonadism, diabetes, and other endocrine problems. Adults: acromegaly: excessive growth of jaw, hands, feet, enlarged tongue and organ enlargement, causing metabolic disorders.

Hypothyroidism Signs & Symptoms

Cold intolerance Weight gain Lethargy Fatigue Memory deficits Poor attention span Muscle cramps Constipation Decreased fertility Puffy face Hair loss Brittle nails

Syndrome of inappropriate ADH secretion (SIADH):

Common condition in patients who sustain brain injury or those who undergo neurosurgery for a brain disorder.

Syndrome of inappropriate ADH secretion (SIADH): Pathophysiology

Excess ADH Secretion high despite low serum osmolarity

Hyperthyroidism

Excessive secretion of T3 and T4 Grave's Disease: most common cause, an autoimmune stimulation of the thyroid gland (also called thyrotoxicosis). Other causes include thyroid adenoma, excessive pituitary TSH secretion, subacute thyroiditis, toxic multi nodular goiter, excessive iodine ingestion (Joe-Basedow syndrome), and excessive thyroid hormone replacement.

Symptoms of Diabetes Insipidus (DI)

Excessive urine volume - hypotonic, dilute and tasteless (insipid). Excessive thirst (polydipsia) - may be intense or uncontrollable, usually with the need to drink large amounts of water. Excessive urination, often needing to urinate every hour throughout the day and night. Dehydration Confusion Disorientation Myoclonus Seizures Coma

Parathyroid Gland

Four pea-sized glands nestled within the thyroid tissue of the neck. The glans produce and secrete parathyroid hormone (PTH) in response to hypocalcemia and breakdown bone to re-establish normal calcium in the blood.

Diabetes Insipidus (DI) Causes: Neuro

Head trauma Intracranial surgery Sarcoidosis Brain tumor

Syndrome of inappropriate ADH secretion (SIADH) Causes

Head trauma/CNS tumors Post-surgical Ectopic tumor production Liver disease Lung cancer/pulmonary disease Hypothyroidism Adrenal insufficiency

Diagnosis of Hypothyroidism

High TSH levles Low free T3 Low free T4 Antithyroglobulin (anti-Tg) Antithyroperoxidase (anti-TPO) antibodies In primary ( blank ), there is low hormone secretion by the thyroid gland, which constantly signals the pituitary to secrete TSH.

Diabetes Insipidus (DI) Causes: Nephro

Hypokalemia Hypercalcemia Hypothermia Chronic renal insufficiency Lithium Alcohol

Other Groups of Hormones:

Hypothalamic Hormones: Discovered in 1969 Gastrointestinal Hormones: More than 26 GI polypeptides Opioid Peptides: Endogenic opioids Tissue Growth Factors: Epidermal growth factor, nerve growth factor, PDGF, IGF...) Atrial natriuretic hormone (ANF) Transforming growth factors and hematopoietic and other growth factors (FGF..) Endothelial factors (endothelnes, EDRF...) Cytokines (interleukins, interferon, TNF...)

Adrenal Gland

Hypothalamic corticotropin-releasing factor (CRF) -> pituitary adrenocorticotropic hormone (ACTH) -> stimulates the adrenal gland. Disorders of the adrenal gland mainly consist of adrenal overactivity (Cushing's syndrome) or adrenal insufficiency (Addison's disease).

Diabetes Insipidus Pathophysiology: Nephrogenic

Insensitivity to ADH

Hypothyroidism

Insufficient levels of thyroid hormones T3 and T4. Hashimoto's thyroiditis, an autoimmune disorder, is the most common cause of hypothyroidism. Thyroid receptor antibodies. Antithyroglobulin antibody. Antithyroperoxidase antibody: hallmark of the disorder.

Subclinical Hypothyroidism

Is common in elderly individuals, can cause subtle neuropsychiatric problems such as disorientation, depression, and pseudo dementia.

General Characteristics of Hormones:

They have specific rates and patterns of secretion (diurnal, pulsatile, cyclic patters, pattern that depends on level of circulating substrates). They operate within feedback loops/systems, either positive (rare) or negative, to maintain an optimal internal environment. They affect only cells with appropriate receptors -> specific cell function(s) is initiated. They are excreted by the kidney, deactivated by the liver or by other mechanisms.

What do hormones do?

They regulate the transport of ions, substrates and metabolites across the cell membrane: - to stimulate transport of glucose and amino acids. - to influence ionic transport across the cell membrane. - to influence epithelial transporting mechanisms. - to stimulate or inhibit cellular enzymes. - to influence the cells genetic information.

Graves' Disease (Hyperthyroidism)

Thyroid-stimulating antibodies bind to and activate thyrotropin receptors within the thyroid gland, causing the gland to enlarge and continually synthesize thyroid hormones.

Anterior Pituitary Hormones

Thyrotropin, or thyroid-stimulating hormone (TSH) Gonadotropins; follicle-stimulating hormone (FSH) and luteinizing hormone (LH) Somatotropin or growth hormone (GH) Corticotropin, or adrenocorticotropic hormone (ACTH) Prolactin

Syndrome of inappropriate ADH secretion (SIADH): Treatment

Treat the underlying case, if known. Water restriction of about 500 - 1500 mL/d Correct Na+ deficit: no more than 10 mEq/L in 24 hours, 18 mEq/L n 48 hours - 0.9% NaCl - 3% NaCl - NaCl enteral tablets - 2-3g TID Vasopressin receptor antagonists: inhibition of the AVP V2 receptor reduces the number of aquaporin-2 water channels in the renal collecting duct; There are 2 aquaretics that are currently FDA approved: - Conivaptan (Vaprisol_ - Tolvaptan Loop diuretic: usually used in conjunction with normal saline to replenish the Na+ excreted with the diuresis. Demeclocycline.

Technetium Scan Using a Radioactive Isotope

Used to differentiate malignant from benign thyroid nodules. The scan identifies nodules as hot, warm, or cold according to their uptake of radioactive isotope. A hot nodule is a hyperfunctioning tumor, a warm nodule indicates normal tissue, and a cold nodule is hypo functional tissue, which is sometimes malignant.