CH13: Altered Hormonal and Metabolic Regulation
The nurse is teaching a client how to collect a 24-hour urine sample for cortisol levels. The client asks why a blood sample cannot just be taken since collecting urine for 24-hours is inconvenient. How should the nurse respond?
"Because cortisol levels fluctuate, collecting a sample over time will be more accurate." Explanation: Measurements of urinary hormone or hormone metabolite excretion often are done on a 24-hour urine sample and provide a better measure of the client's overall hormone levels. Cortisol can be measured using blood, but this only represents an isolated measurement and will not be as accurate as the averaged levels collected with a 24-hour urine test. The disadvantages are that timed urine collections often are difficult to obtain and urine samples may be accidentally discarded or inaccurately preserved. Drugs or disease states that alter hormone metabolism may still interfere with the test results. The reason for the use of the urine test is not related to it being noninvasive, and blood testing is considered minimally invasive and safe.
negative feedback loop
(A feedback loop that causes a system to change in the opposite direction from which it is moving) -the hypothalamus and pituitary act as sensors that are constantly gauging the levels of hormones in the body ie: aldosterone levels adjust based on sodium and potassium levels in the body
hormone receptors
(Located in the plasma membrane or in the intracellular compartment of the target cell) -recognize a specific hormone and translate the hormonal signal into a cellular response
Myxedema
(caused by extreme deficiency of thyroid secretion; hypothyroidism) Protein-carbohydrate complexes accumulate in the extracellular matrix drawing water into the tissues, resulting in boggy, nonpitting, edematous tissues especially of the face and mucous membranes, hands, and feet
positive feedback loop
(feedback loop that causes a system to change further in the same direction) presence of the hormone stimulates increased production of the hormone until there is an interruption of the cycle ie:oxytocin during childbirth
the cerebral cortex
(gray matter of the brain) the outer region of the cerebrum containing intricately interconnected nerve cells -the body's ultimate control and information-processing center
ADH (antidiuretic hormone)
(produced in hypothalamus, secreted by posterior pituitary) -controls fluid balance by regulating reabsorption of water by the kidneys -based on serum osmolality and extracellular fluid volume
Thyrotoxic crisis (Thyroid Storm)
- rare but potentially fatal complication of hyperthyroidism where an overwhelming release of thyroid hormones exerts intense stress on the metabolism -commonly precipitated by surgery, trauma, infection, stress, or pregnancy (associated with Graves Disease/ sudden worsening of hyperthyroidism)
Which clinical manifestations following thyroidectomy would alert the nurse that the client is going into a life-threatening thyroid storm? Select all that apply.
-Temperature of 104.2°F (40.1°C) -Telemetry showing heart rate of 184 -Extremely agitated Explanation: Thyroid storm, or crisis, is an extreme and life-threatening form of thyrotoxicosis, rarely seen today. When it does occur, it is seen most often in undiagnosed cases or in persons with hyperthyroidism that has not been adequately treated. It often is precipitated by stress such as an infection, diabetic ketoacidosis, physical or emotional trauma, or manipulation of a hyperactive thyroid gland during thyroidectomy. It is manifested by a very high fever, extreme cardiovascular effects (tachycardia, HF, angina), and severe CNS effects (agitation, restlessness, and delirium).
A student nurse is taking a test on the endocrine system. From the list of clinical manifestations, she needs to select the ones she would see in hypothyroidism. Which answers should she select? Select all that apply.
-Weight gain despite loss of appetite -Coarse, brittle hair -Puffy face with swollen eyelids Explanation: The hypometabolic state associated with hypothyroidism is characterized by a gradual onset of weakness and fatigue, a tendency to gain weight despite a loss of appetite, and cold intolerance. As the condition progresses, the skin becomes dry and rough and the hair becomes coarse and brittle. Reduced conversion of carotene to vitamin A and increased blood levels of carotene may give the skin a yellowish color. The face becomes puffy with edematous eyelids, and there is thinning of the outer third of the eyebrows. Nervousness with fine muscle tremors and heat intolerance are signs of hyperthyroidism.
The nurse is planning care for a client with acute Addison disease. Which actions will the nurse include in the plan of care? Select all that apply.
-frequent assessment of blood pressure -give hypotonic intravenous fluids -administration of hydrocortisone medication -frequent assessment of serum electrolytes Explanation: Addison disease is caused by a deficit in cortisol and aldosterone levels. The primary treatment is replacement of these hormones with hydrocortisone medications. In acute Addison disease, maintenance of perfusion pressures and correction of electrolyte imbalances are a priority, so the nurse monitors blood pressure and electrolyte levels closely. Because hyponatremia is present in Addison disease, isotonic IV fluids rather than hypotonic ones are indicated. Dietary sodium may need to be increased, not restricted.
The nurse is assessing a client with hypothyroidism who is prescribed levothyroxine. Which findings will the nurse report as evidence that the client's dose of levothyroxine may need to be reduced? Select all that apply.
-heat intolerance -heart rate of 110 beats/min -increased sweating Explanation: Overtreatment with the synthetic hormone levothyroxine will cause hyperthyroidism. Therefore, evidence of supratherapeutic levels of levothyroxine align with the signs and symptoms of hyperthyroidism, including weight loss, agitation, increased sweating, heat intolerance, diarrhea rather than constipation, and increased heart rate (tachycardia). Nonpitting edema supports the presence of myxedema, which is associated with low, rather than elevated, thyroid hormone levels.
When educating a client with possible glucocorticoid dysfunction, the nurse will explain that the CRH controls the release of ACTH. The best time to perform the blood test to measure peak ACTH levels would be:
06:00 to 08:00 AM Explanation: Levels of cortisol increase as ACTH levels rise and decrease as ACTH levels fall. There is considerable diurnal variation in ACTH levels, which reach their peak in the early morning (around 6 to 8 AM) and decline as the day progresses.
The nurse is caring for a client diagnosed with Graves disease. Which assessment findings will the nurse expect upon assessment? Select all that apply.
1. Thin hair 2. Tremor 3. Muscle wasting Explanation: Graves disease, an excessive stimulation of the thyroid gland, is the most common cause of hyperthyroidism and is the most common autoimmune condition in the United States. Manifestations of Graves disease include thin hair, weight loss, tremor, muscle wasting, and tachycardia.
Which pediatric assessment finding would the nurse recognize as an example of precocious puberty?
A 7-year-old female with early menarche Explanation: The 7-year-old needs to be evaluated. Precocious puberty is defined as the appearance of secondary sexual development before the age of 8 years in girls. There is a shift toward a "new normal" of earlier ages of puberty, with black girls entering puberty earlier than white girls and children who are obese entering puberty at earlier ages than children of normal body weight for age. In boys of both races, the lower age limit remains 9 years; however, it is recognized that puberty can develop earlier in boys with obesity. The assessment findings of the 12-, 13-, and 16-year-olds are not of concern because they are normal findings.
One of the earliest signs of Cushing syndrome is the loss of variable diurnal secretion of cortisol-releasing hormone (CRH) and:
ACTH Explanation: One of the earliest signs of Cushing syndrome, a disorder of cortisol excess, is the loss of diurnal variation in CRH and adrenocorticotropin hormone (ACTH) secretion, with corticotropin-releasing hormone (CRH) controlling the release of ACTH.
A client with small cell carcinoma lung cancer may secrete an excess of which hormone, causing an ectopic form of Cushing syndrome due to a nonpituitary tumor?
ACTH Explanation: The third form (of Cushing syndrome) is ectopic Cushing syndrome, caused by a nonpituitary ACTH-secreting tumor. Certain extra pituitary malignant tumors such as small cell carcinoma of the lung may secrete ACTH or, rarely, CRH that can produce Cushing syndrome.
The health care provider is reviewing diurnal variation pattern in adrenocorticotropic (ACTH) levels. Select the typical diurnal variation pattern in adrenocorticotropic (ACTH) levels.
ACTH peaks in the morning and declines throughout the day. Explanation: ACTH levels have diurnal variation in which they reach their peak in the early morning (around 6 to 8 AM) and decline as the day progresses related to rhythmic activity of the CNS. The diurnal pattern is reversed in people who work during the night and sleep during the day. The rhythm also may be changed by physical and psychological stresses, endogenous depression, and liver disease or other conditions that affect cortisol metabolism.
Cyclic adenosine monophosphate (cAMP) performs which role in the functioning of the endocrine system?
Acting as a second messenger to mediate hormone action on target cells Explanation: cAMP is one of the most common second messengers, whose role is to generate an intracellular signal in response to cell surface receptor activation by a hormone. cAMP does not mediate hormone synthesis, act as a receptor itself, or inactivate hormones.
The signs and symptoms of abrupt cessation of pharmacologic glucocorticoids closely resemble those of which disease process?
Addison disease Explanation: Although the etiology differs, the adrenal cortical insufficiency resulting from the abrupt cessation of glucocorticoids is nearly identical to Addison disease in terms of physiologic effects. -Cushing syndrome refers to the manifestations of hypercortisolism. Cushing disease is caused by glucocorticoid hormone excess. -Graves disease is a state of hyperthyroidism, goiter, and ophthalmopathy.
A client has been diagnosed with dysfunction of the anterior pituitary gland. The nurse is aware that which hormones will likely be affected? Select all that apply.
Adrenocorticotropic hormone (ACTH) Thyroid-stimulating hormone (TSH) Growth hormone (GH) Luteinizing hormone (LH)
Select the category of hormones that include norepinephrine and epinephrine.
Amines and amino acids Explanation: Hormones can be divided into three categories: (1) amines and amino acids; (2) peptides, polypeptides, proteins, and glycoproteins; and (3) steroids. The amines include norepinephrine and epinephrine. The second category, the peptides, includes polypeptides, proteins, and glycoproteins. The third category consists of the steroid hormones, which are derivatives of cholesterol.
Which individual displays the precursors to acromegaly?
An adult with an excess of growth hormone due to an adenoma Explanation: When growth hormone (GH) excess occurs in adulthood or after the epiphyses of the long bones have fused, it causes a condition called acromegaly, which represents an exaggerated growth of the ends of the extremities.
The number of hormone receptors on a cell may be altered for any of several reasons. The most appropriate response would be:
Antibodies may destroy or block the receptor proteins. Explanation: The number of hormone receptors on a cell may be altered for any of several reasons. Antibodies may destroy or block the receptor proteins. -Increased or decreased hormone levels often induce changes in the activity of the genes that regulate receptor synthesis. -Decreased hormone levels often produce an increase in receptor numbers by means of a process called up-regulation, increasing the sensitivity of the body to existing hormone levels. -Sustained levels of excess hormone often bring about a decrease in receptor numbers by down-regulation, producing a decrease in hormone sensitivity.
hormones from the posterior pituitary
Antidiuretic hormone (ADH) Oxytocin (OT)
A client has developed a tumor of the posterior pituitary gland. The client is at risk for problems with secretions of:
Antidiuretic hormone (ADH) and oxytocin Explanation: The posterior pituitary secretes ADH and oxytocin/vasopressin, while the anterior pituitary secretes the hormones listed in the other choices.
The nurse is caring for a client being treated for diabetes insipidus after cranial surgery. The client has intravenous (IV) fluids infusing and has an indwelling urinary catheter. The nurse notes no urine output in the past hour. Which action is the nurse's priority?
Assess the urinary catheter and drainage system. Explanation: Because the client has an indwelling urinary catheter, the nurse should determine if there is an occlusion preventing the flow of urine as the priority. If the catheter is kinked or occluded, the bladder could quickly become distended and reflux urine up the ureters, leading to possible hydronephrosis. Once visual inspection for occlusion of tubing is done, the nurse would then perform a bedside ultrasound to measure bladder volume in case the catheter had an internal occlusion preventing urine flow. Once these assessments were done, the nurse would stop the IV fluids only if there was evidence of urinary obstruction. Once the status of bladder drainage was determined, the nurse would then collect other assessment information such as serum sodium level prior to contacting the health care provider. The nurse would clarify the administration of desmopressin only if evidence supporting overtreatment was present.
A client with a suspected diagnosis of primary hypothyroidism would most likely demonstrate which serum laboratory value?
Elevated thyroid-stimulating hormone (TSH) and decreased thyroxine (T4) Explanation: A low serum T4 and elevated TSH levels are characteristic of primary hypothyroidism. -Elevated TSH, T4, and T3 may indicate hyperthyroidism. -Decreased levels may be due to suppression by medication.
The newborn nursery nurse is obtaining a blood sample to determine if a newborn has congenital hypothyroidism. What long-term complication is the nurse aware can occur if this test is not performed and the infant has congenital hypothyroidism?
Cretinism Explanation: Congenital hypothyroidism is a common cause of preventable intellectual disability. It affects approximately 1 in 4000 infants. The manifestations of untreated congenital hypothyroidism are referred to as cretinism. The term does not apply to the normally developing infant in whom replacement thyroid hormones therapy was instituted shortly after birth.
The nurse is reviewing the test results of a client who was given thyrotropin-releasing hormone (TRH) to evaluate the function of the pituitary gland. The nurse would recognize pituitary dysfunction as:
Decreased TSH levels Explanation: Stimulation tests are used when hypofunction of an endocrine organ is suspected. Failure to increase TSH levels after a TRH stimulation test suggests an inadequate capacity to produce TSH by the pituitary (i.e., the pituitary is dysfunctional in some way).
Which effect of thyroid hormone deficit alters the function of all major organs in the body?
Decreases metabolism Explanation: Thyroid hormone has two major functions: it increases metabolism and protein synthesis, and it is necessary for growth and development in children, including mental development and attainment of sexual maturity. Altered levels of thyroid hormone affect all the major organs in the body - hypothyroidism decreases metabolism and protein synthesis. -Thyroid hormone deficit decreases the absorption of glucose from the gastrointestinal tract. -Because vitamins are essential parts of metabolic enzymes and coenzymes, an increase (rather than decrease) in metabolic rate causes the use of vitamins and tends to cause vitamin deficiency.
Which pathophysiologic phenomenon may result in a diagnosis of Cushing disease?
Excess ACTH production by a pituitary tumor Explanation: Three important forms of Cushing syndrome result from excess glucocorticoid production by the body. one being a pituitary form, which results from excessive production of ACTH by a tumor of the pituitary gland. -Hypopituitarism and destruction of the adrenal cortex are associated with Addison disease. -Disruption of the HPA system is not implicated in the etiology of Cushing disease.
The nurse is caring for a client with adrenal hyperplasia. What is the nurse's understanding of the etiology of the condition?
Excessive hormonal stimulation Explanation: Excessive stimulation of the endocrine gland can result in hyperplasia and an excessive amount of hormone production and secretion. The remaining answer choices do reflect the etiology of hyperplasia.
A nurse on a medical unit is providing care for a 37-year-old female client who has a diagnosis of Graves disease. Which assessments should the nurse prioritize?
Eye health and visual acuity Explanation: The ophthalmopathy of Graves disease can cause severe eye problems, including tethering of the extraocular muscles resulting in diplopia; involvement of the optic nerve, with some visual loss; and corneal ulceration because the lids do not close over the protruding eyeball (due to the exophthalmos). Eye assessment is consequently a priority over assessment of skin integrity, cognition, or musculoskeletal status.
Abnormal stimulation of the thyroid gland by TSH-receptor antibodies is implicated in cases of:
Graves disease Explanation: Graves disease is an autoimmune disorder characterized by abnormal stimulation of the thyroid gland by thyroid-stimulating antibodies (TSH-receptor antibodies) that act through the normal TSH receptors.
Which hormone is produced by the anterior pituitary gland?
Growth hormone (GH) Explanation: GH is among the hormones produced and released by the anterior pituitary. -Oxytocin is a posterior pituitary hormone, whereas CRH is produced by the hypothalamus. -Norepinephrine and epinephrine are produced by the adrenal medulla.
The nurse is performing an assessment for a client who has hyperthyroidism that is untreated. When obtaining vital signs, what is the expected finding?
Heart rate 110 and bounding Explanation: Cardiovascular and respiratory functions are strongly affected by thyroid function. With an increase in metabolism, there is a rise in oxygen consumption and production of metabolic end products, with an accompanying increase in vasodilation. Blood volume, cardiac output, and ventilation are all increased. Heart rate and cardiac contractility are enhanced as a means of maintaining the needed cardiac output. Blood pressure is likely to change little because the increase in vasodilation tends to offset the increase in cardiac output.
Which statement best explains the function of hormone receptors?
Hormone receptors recognize a specific hormone and translate the hormonal signal into a cellular response. Explanation: Hormone receptors are complex molecular structures that are located either on the surface of or inside target cells. The function of these receptors is to recognize a specific hormone and translate the hormonal signal into a cellular response.
Which gland acts as a signal relaying bridge between multiple body systems and the pituitary gland?
Hypothalamus Explanation: The activity of the hypothalamus is regulated by both hormonally mediated signals (e.g., negative feedback signals) and by neuronal input from a number of sources. -Neuronal signals are mediated by neurotransmitters such as acetylcholine, dopamine, norepinephrine, serotonin, gamma-aminobutyric acid (GABA), and opioids. -Cytokines that are involved in immune and inflammatory responses, such as the interleukins, also are involved in the regulation of hypothalamic function. This is particularly true of the hormones involved in the hypothalamic-pituitary-adrenal axis. Thus, the hypothalamus can be viewed as a bridge by which signals from multiple systems are relayed to the pituitary gland. This cannot be said of the other options.
A health care provider is assessing a client for a potential endocrine disorder. Assessment findings identify abnormalities with emotion, pain, and body temperature. Which mechanism of endocrine control will require further laboratory/diagnostic assessment?
Hypothalamus Explanation: The hypothalamus is the coordinating center of the brain for endocrine, behavioral, and autonomic nervous system function. It is at the level of the hypothalamus that emotion, pain, body temperature, and other neural input are communicated to the endocrine system. -The anterior pituitary regulates several physiologic processes, including stress, growth, reproduction, and lactation. -The cerebellum is involved in motor control -the cerebral cortex is associated with sensory, motor, and association
The hypothalamic-pituitary-thyroid axis
Hypothalmus → (TRH) Thyrotropin Releasing Hormone → Ant Pituitary to Increase (TSH) Thyroid Stimulating Hormone →Thyroid Gland to produce T3 and T4 -Negative Feedback System -disturbances to this axis are linked to mood disorders -those w/low thyroid levels often become depressed
An infant whose mother had myxedema during the pregnancy has failed to meet standards for growth and is developmentally delayed. Which hormonal imbalance is this child exhibiting?
Hypothyroidism Explanation: Thyroid hormone is necessary for metabolism at all ages, as well as growth and development during childhood. Uncorrected thyroid insufficiency in childhood leads to cretinism, a condition with marked physical and intellectual disability. Myxedema is the term used for thyroid insufficiency in adults.
When the nurse is performing a health history for a client who is being admitted for hyperthyroidism, what symptom does the client report that the nurse would find associated with this disorder?
Increase in appetite Explanation: Thyroid hormone enhances gastrointestinal function, causing an increase in motility and production of GI secretions that often results in diarrhea. An increase in appetite and food intake accompanies the higher metabolic rate that occurs with increased thyroid hormone levels. At the same time, weight loss occurs because of the increased use of calories.
The nurse is discussing positive feedback mechanisms. Which example best explains this mechanism?
Increased estradiol production causes increased follicle-stimulating hormone (FSH) production. Explanation: The positive feedback mechanism regulates hormones as follows: a rising level of a hormone causes another gland to release a hormone that is stimulating to the first. The other choices represent negative feedback mechanisms of control.
Following a meal, a client's blood glucose level has increased. In addition, the client's pancreas has increased the amount of insulin produced and released. Which phenomenon has occurred?
Increased hormone level according to a negative feedback mechanism
A client comes to the clinic with fatigue and muscle weakness. The client also states she has been having diarrhea. The nurse observes the skin of the client has a bronze tone and when asked, the client says she has not had any sun exposure. The mucous membranes of the gums are bluish-black. When reviewing laboratory results from this client, what does the nurse anticipate seeing?
Increased levels of ACTH Explanation: Hyperpigmentation results from elevated levels of ACTH. The skin looks bronzed or suntanned in exposed and unexposed areas, and the normal creases and pressure points tend to become especially dark. The gums and oral mucous membranes may become bluish-black. The amino acid sequence of ACTH is strikingly similar to that of melanocyte stimulating hormone; hyperpigmentation occurs in more than 90 percent of persons with Addison disease and is helpful in distinguishing the primary and secondary forms of adrenal insufficiency.
A client diagnosed with metabolic syndrome and growth hormone (GH) deficiency will likely display which physical assessment finding?
Increased visceral fat Explanation: GH deficiency is associated with a cluster of cardiovascular risk factors including central adiposity (associated with increased visceral fat), insulin resistance, and dyslipidemia. These features also are associated with the metabolic syndrome.
While teaching a science class, the instructor mentions that both autocrine and paracrine hormonal actions occur without entering the bloodstream. A student asks, "What cells do paracrine actions affect?" Which response is correct?
Local Explanation: Paracrine actions are hormonal interactions with local cells other than those that produce the hormone; autocrine actions are with self-cells (cells from which they were produced). Both autocrine and paracrine hormonal actions affect target cells. Neither paracrine nor autocrine actions affect cell storage.
he most common cause of thyrotoxicosis is Graves disease. When assessing this client, the nurse should put priority on which sign/symptom?
Ophthalmopathy Explanation: Graves disease is characterized by a triad of hyperthyroidism, goiter, ophthalmopathy (exophthalmos), or less commonly, dermopathy (pretibial edema due to accumulation of fluid and glycosaminoglycans). -Even in persons without exophthalmos (i.e., bulging of the eyeballs seen in ophthalmopathy), there is an abnormal retraction of the eyelids and infrequent blinking such that they appear to be staring. Although the myxedema of hypothyroidism is most obvious in the face and other superficial parts, it also affects many of the body organs. Common to all types of thyrotoxicosis, rather than unique to Graves disease, cholesterol blood levels are decreased; muscle proteins are broken down and used as fuel, which accounts for the muscle fatigue that occurs with all types of hyperthyroidism.
The most common cause of thyrotoxicosis is Graves disease. When assessing this client, the nurse should put priority on which sign/symptom?
Ophthalmopathy Explanation: Graves disease is characterized by a triad of hyperthyroidism, goiter, ophthalmopathy (exophthalmos), or less commonly, dermopathy (pretibial edema due to accumulation of fluid and glycosaminoglycans). Even in persons without exophthalmos (i.e., bulging of the eyeballs seen in ophthalmopathy), there is an abnormal retraction of the eyelids and infrequent blinking such that they appear to be staring. Although the myxedema of hypothyroidism is most obvious in the face and other superficial parts, it also affects many of the body organs. Common to all types of thyrotoxicosis, rather than unique to Graves disease, cholesterol blood levels are decreased; muscle proteins are broken down and used as fuel, which accounts for the muscle fatigue that occurs with all types of hyperthyroidism.
As part of maintaining homeostasis, why are hormones, secreted by endocrine cells, continuously inactivated?
Prevent accumulation Explanation: Continuous inactivation of secreted hormones is necessary to prevent accumulation that could disrupt the feedback mechanism. Increased secretion stimulates production of more receptor sites. Metabolic waste absorption is not a function of the endocrine system.
A client with a history of brain tumors that resulted in partial removal of the pituitary gland years ago expresses concern to the health care provider about whether she will be able to breast-feed her infant. Which physiologic function of the pituitary gland facilitates breast milk production?
Prolactin Explanation: The anterior pituitary gland or adenohypophysis contains five cell types: (1) thyrotrophs, which produce thyrotropin, also called TSH; (2) corticotrophs, which produce corticotropin, also called ACTH; (3) gonadotrophs, which produce the gonadotropins, LH and FSH; (4) somatotrophs, which produce GH; and (5) lactotrophs, which produce prolactin that is involved with breast growth and milk production.
Several hormones, including growth hormone (GH) and thyrotropin-releasing hormone (TRH), are bound to and carried by which substance?
Proteins Explanation: Some hormones, such as steroids and thyroid hormone, are bound to protein carriers for transportation to the target cell destination. Cholesterol is a precursor for steroid hormone. Prohormones have an extra amino acid and convert to hormones in the Golgi complex.
Hormones are chemical messengers that provide which function in the body?
Regulate body functions Explanation: Hormones regulate and integrate body functions. Hormones act on specific target cells, but they cause a variety of effects on tissues. Hormones do not transport other substances; hormones are transported and present in body fluids at all times.
Primary adrenal insufficiency is manifested by:
Serum sodium level of 120 mEq/L (120 mmol/L) (low) and blood glucose level of 48 mg/dL (2.66 mmol/L) (low) Explanation: Primary adrenal insufficiency is adrenal cortical hormone deficiency with elevated adrenocorticotropic hormone (ACTH) levels caused by a lack of feedback inhibition. Manifestations are related primarily to mineralocorticoid deficiency, causing increased urinary losses of sodium, chloride, and water, along with decreased excretion of potassium. The result is hyponatremia, loss of extracellular fluid, decreased cardiac output, and hyperkalemia. Because of a lack of glucocorticoid, the person with Addison disease has poor tolerance to stress. This deficiency causes hypoglycemia, lethargy, weakness, fever, and gastrointestinal symptoms such as anorexia, nausea, vomiting, and weight loss. Hypopigmentation results from elevated ACTH levels.
General adaptation syndrome
Seyle's concept that the body responds to stress with 1. alarm stage: catecholamines and cortisol are released for "fight or flight" 2. resistance stage: negative feedback decreases cortisol levels 3. exhaustion: energy depletion and degeneration of cells, tissues, organs, and organ systems
The physician suspects a client may be experiencing hypofunction of an endocrine organ. Select the most appropriate test to determine organ function.
Stimulation tests Explanation: Stimulation tests are used when hypofunction of an endocrine organ is suspected. Suppression tests are used when hyperfunction of an endocrine organ is suspected. Genetic testing is used for DNA analysis, and imaging may be used as a follow-up after the diagnosis.
A client who has been taking 80 mg of prednisone, a glucocorticoid, each day has been warned by his primary care provider to carefully follow a plan for the gradual reduction of the dose rather than stopping the drug suddenly. What is the rationale for this directive?
Stopping the drug suddenly may cause acute adrenal insufficiency. Explanation: Chronic suppression of the HPA system by the use of steroids causes atrophy of the adrenal gland, and the abrupt withdrawal of drugs can cause acute adrenal insufficiency. Activity of the HPA system is consequently insufficient. The efficacy of the drug is not the primary concern, and necrosis of the gland itself does not occur.
A client has developed the facial appearance that is characteristic of myxedema, along with an enlarged tongue, bradycardia, and voice changes. Which treatment modality is most likely to benefit this client?
Synthetic preparations of T3 or T4 Explanation: Myxedema and the client's other signs are associated with hypothyroidism, which necessitates thyroid hormone replacement. Beta-adrenergic blocking drugs and antithyroid drugs are indicated in the treatment of hyperthyroidism, whereas treatments relevant to adrenal cortical function are not relevant to hypothyroidism.
Hyperthyroidism that is inadequately treated can cause a life-threatening condition known as a thyroid storm. What are the manifestations of a thyroid storm? Select all that apply.
Tachycardia Delirium Very high fever Explanation: Thyroid storm is manifested by a very high fever, extreme cardiovascular effects (e.g., tachycardia, congestive failure, and angina), and severe CNS effects (e.g., agitation, restlessness, and delirium). The mortality rate is high. Very low fever and bradycardia are not manifestations of a thyroid storm.
Tertiary hypothyroidism
Tertiary insufficient release of TRH from the hypothalamus, anterior pituitary & thyroid are under-stimulated (↓TRH, ↓TSH, ↓TH) • Tumors, trauma, radiation therapy
The nurse is educating a newly diagnosed client with Hashimoto thyroiditis who is to be discharged from the acute care facility. What should the nurse be sure to include in the education to prevent complications?
The client should be informed about the signs and symptoms of severe hypothyroidism and the need for early intervention. Explanation: Prevention is preferable to treatment and entails special attention to high-risk populations, such as women with a history of Hashimoto thyroiditis. These persons should be informed about the signs and symptoms of severe hypothyroidism and the need for early medical treatment.
The nurse is providing discharge instructions for a client with Graves disease who has ophthalmopathy. What should the nurse be sure to include in the instructions to decrease exacerbation of this clinical manifestation?
The client should be strongly urged not to smoke. Explanation: Ophthalmopathy can also be aggravated by smoking, which should be strongly discouraged. It is not necessary for the client to avoid contact with others. Alcohol is not contraindicated but should be limited when taking any medication regimen. The client should not adjust the doses of medications without first consulting the physician.
When describing to a client newly diagnosed with diabetes how insulin is regulated, the nurse will draw upon her knowledge of which hormonal regulation mechanism?
The hypophysis (pituitary plus hypothalamus) and hypothalamus stimulatory hormones regulate the release and synthesis of anterior pituitary hormones. -The levels of hormones such as insulin and antidiuretic hormone (ADH) are regulated by feedback mechanisms that monitor substances such as glucose (insulin) and water (ADH) in the body. -The levels of many of the hormones are regulated by feedback mechanisms that involve the hypothalamic-pituitary-target cell system.
When describing to a client newly diagnosed with diabetes how insulin is regulated, the nurse will draw upon her knowledge of which hormonal regulation mechanism?
The hypothalamic-pituitary-target cell system Explanation: The hypophysis (pituitary plus hypothalamus) and hypothalamus stimulatory hormones regulate the release and synthesis of anterior pituitary hormones. The levels of hormones such as insulin and antidiuretic hormone (ADH) are regulated by feedback mechanisms that monitor substances such as glucose (insulin) and water (ADH) in the body. The levels of many of the hormones are regulated by feedback mechanisms that involve the hypothalamic-pituitary-target cell system
The nurse is teaching a client who has been newly diagnosed with hypothyroidism about the function of the thyroid. Which statement about the role of the thyroid gland is most accurate?
The thyroid gland is responsible for increasing the metabolic rate. Explanation: The thyroid gland produces thyroid hormones, T3 and T4. These hormones increase the metabolic rate; increase protein and bone turnover; increase responsiveness to catecholamines; are necessary for fetal and infant growth and development. -The parathyroid gland regulates calcium metabolism. The adrenal glands regulate "flight or fight" and the testes or ovaries regulate development of secondary sex characteristics.
hormones from anterior pituitary
Thyroid Stimulating hormone (TSH) Adrenocorticotropic hormone (ACTH) Follicle Stimulating hormone (FSH) Luteinizing hormone (LH) Growth Hormone (GH) Prolactin
The nurse explains to a client in labor who has demonstrated ineffective contractions impeding progression of labor that the health care provider has added oxytocin infusion to the orders. What does the nurse teach the client is the purpose of oxytocin?
To stimulate contraction of the uterus Explanation: The role of oxytocin is to stimulate contraction of the pregnant uterus and milk ejection from breasts after childbirth. An infusion of oxytocin will promote effective contractions.
Diabetes insipidus (DI)
a condition of insufficient ADH that results in the inability of the body to concentrate or retain water S/S: polyuria, excessive thirst, serum hyperosmolality, severe dehydration, highly dilute urine D: measurement of serum solute concentration, ADH levels, and urine-specific gravity of 1.005 or less and a urine osmolality less than 200 mOsm/kg T: IV hydration wi hypotonic solution & desmopressin (a synthetic vasopressin analog acting like a diuretic)
The hypothalamus
a neural structure lying below the thalamus; -directs eating, drinking, body temperature, and emotion - helps govern the endocrine system via a signal relaying bridge between multiple body systems and the pituitary gland - activity is regulated by both hormonally mediated signals (e.g., negative feedback signals) and by neuronal input from a number of sources
The Adrenal Glands
a pair of endocrine glands that help the body recover from stress and respond to emergencies -regulate "flight or fight"
The Thyroid
a vital hormone gland: It plays a major role in the metabolism, growth and development of the human body -helps to regulate many body functions by constantly releasing a steady amount of thyroid hormones into the bloodstream
autocrine signaling
actions are with self-cells (cells from which they were produced) -the target cell is also the secreting cell -does not affect cell storage receptor cells are also secretory cells meaning the cell is able to produce the hormone and exert an effect on itself
Primary adrenal insufficiency
adrenal cortical hormone deficiency with elevated adrenocorticotropic hormone (ACTH) levels caused by a lack of feedback inhibition -decreased aldosterone and cortisol levels = hypotension (hyponatremic vol contraction), hyperkalemia, metabolic acidosis, skin/mucosal hyperpigmentation (Addison's Disease)
Grave's Disease
an autoimmune disorder characterized by the excessive production of thyroid hormones (hyperthyroidism) -S/S: goiter(myxedema) & ophthalmopathy(thyrotoxicosis); thin hair, weight loss, tremor, muscle wasting, and tachycardia -D: rule out imaging, TSH level (low), -T: Thyroidectomy, Radioactive iodine, Antithyroid agent (med) like Thiamazole or Propylthiouracil
The Pituitary Gland
called the master gland because its hormones control the functions of many target glands and cells
Cretinism
condition of congenital hypothyroidism in children that results in a lack of mental development and dwarfed physical stature; the thyroid gland is either congenitally absent or imperfectly developed
Cerebellum
controls balance, movement, and coordination -located behind the brainstem
hormones from the adrenal cortex
cortisol, aldosterone, and sex hormones
Hypothyroidism
deficient thyroid hormone production (either TSH or TRH) S/S: fatigue, cold intolerance, weakness, weight gain, dry skin, coarse hair, constipation, lethargy, impaired reproduction, goiter and impaired memory
The nurse is caring for a client with a hormonal disorder that is widely affecting many body systems. The nurse recognizes that which form of hormone signalling pathway is most likely involved in the client's disorder?
endocrine Explanation: The endocrine pathway involves hormones being produced, secreted, and traveling through blood vessels to distant cells to have an effect, thus having the potential to affect entire body systems. -In the paracrine pathway hormones are produced in a cell, secreted, and act directly on nearby receptive cells. -The autocrine pathway is similar to the paracrine pathway except that the receptor cells are also secretory cells meaning the cell is able to produce the hormone and exert an effect on itself. -There is no pathway known as local mediation.
polyuria
excessive/ overproduction of urine
paracrine signaling
hormonal interactions with local cells other than those that produce the hormone -affect target cells. -does not affect cell storage
Endocrine pathway
hormones are produced in a cell, secreted, and travel through blood vessels to distant cells, attach to receptors, and act on that cell
Neuroendocrine pathway
hormones are produced in a neuron, secreted, travel along the axon to the synapse, are released, are taken up into the vascular system, and travel to distant cells with the appropriate receptors to exert an effect
Synaptic pathway
hormones are produced in the neuron, secreted, and travel along the axon to the synapse where they are released and taken up by a nearby neuron with the appropriate receptors to exert an effect
Parathyroid
in the neck; controls the calcium levels in your body, and normals the bone growth
Which physiologic process best exemplifies a positive feedback mechanism?
increase in prolactin secretion that occurs with more frequent breastfeeding Explanation: A positive feedback mechanism occurs when one hormonal or physiologic factor stimulates further hormonal release, creating a cascade that will increase until the stimulus is reduced. Because the stimulation of breastfeeding releases prolactin that enhances milk production, this is a positive feedback mechanism.
Reticular activating system
increases alertness and muscle tension and contributes to stimulation of the autonomic nervous system
Thalamus
intensifies sensory input related to the stressor such as vision, hearing, and smell
Stimulation test
involves the introduction of an element that stimulates the production of another factor or hormone followed by measurement of that hormone
Hypotonicity
plasma osmolality less than 280 mOsm/kg
The nurse is teaching a client newly diagnosed with hypothyroidism. The nurse teaches that thyroid hormone is transported by which?
protein carriers Explanation: Some hormones, such as steroids and thyroid hormone, are bound to protein carriers for transportation to the target cell destination. The extent of carrier binding influences the rate at which hormones leave the blood and enter the cells. Cholesterol is a precursor for steroid hormone. Prohormones have an extra amino acid and are converted to hormones in the Golgi complex.
Cerebral cortex
regulates cognitive activities such as intense focus, planning, attention, and persistence
Limbic system
regulates emotional activities such as fear, anxiety, anger, and excitement, and stimulates the reticular activating system.
Hyponatremia
serum sodium less than 135 mEq/L -deficient sodium in the blood
Catecholamines (epinephrine and norepinephrine)
stimulates by sympathetic NS; increases heart rate, blood pressure, blood glucose levels and dilates lung passageways
menarche
the first menstrual period
Secondary hypothyroidism
the pituitary gland is underactive (↓TSH); thyroid gland is under-stimulated (↓TH).
precocious puberty
the very early onset and rapid progression of puberty -begins before the age of 8 in girls and 9 in boys
In major athletic competition, athletes are required to submit to liquid chromatography testing looking for:
use of performance-enhancing agents to increase the chances of winning. Explanation: For some steroid or peptide hormones, mass spectrometry is becoming increasingly useful and can be combined with other analytical techniques, such as liquid chromatography. These approaches provide definitive identification of the relevant hormone or compound according to its chemical or physical characteristics (e.g., unequivocal detection of performance-enhancing agents in sports).
