Porth's Patho: Endocrine Ch. 40
Select the most appropriate statement that describes the function of hormones. -Hormones function as modulators of cellular and systematic responses. -Hormones respond to cellular and systematic interactions. -Hormones initiate reactions of cellular and systematic responses. -Hormones have little involvement in cellular and systematic responses.
-Hormones function as modulators of cellular and systematic responses.
Which statement describes how water-soluble peptides, such as parathyroid hormone or glucagon, exert their effect on cells? -They serve as second messengers. -They bind to receptors. -They activate the pyruvate pathway. -They diffuse across the cell membrane.
-They bind to receptors Water-soluble peptides cannot pass through the lipid layer of the cell membrane, so they plug into receptors that send signals to G proteins. Steroids and other lipid-soluble hormones diffuse across the cell membrane where they bind to an intracellular receptor.
A nurse who works in the office of an endocrinologist is orienting a new staff member. Which teaching point should the nurse include in the orientation? -"The regulation of homeostasis requires that hormones be absent from the body when their effect is not needed." -"Sometimes hormones act locally on the area where they were produced, as in the case of endocrine actions." -"A single hormone can act on not only one process or organ but often on several different locations or processes." -"It's uncommon for production of hormones to be far removed from the tissue where they ultimately exert their effect."
A single hormone can act on not only one process or organ but often on several different locations or processes. A single hormone can exert various effects in different tissues, or conversely, a single function can be regulated by several different hormones. Hormones act both distantly from their source and more locally, as in the case of autocrine and paracrine actions. Hormones are normally present at all times.
Select the category of hormones that include norepinephrine and epinephrine. -Amines and amino acids -Glycoproteins -Peptides -Steroids
Amines and amino acids 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.
To prevent the accumulation of hormones in our bodies, the hormones are constantly being metabolized and excreted. Where are adrenal and gonadal steroid hormones excreted? -Bile and urine -Bile and lungs -Cell metabolites and lungs -Feces and urine
Bile and urine Unbound adrenal and gonadal steroid hormones are conjugated in the liver, which renders them inactive, and then excreted in the bile or urine. Adrenal and gonadal steroid hormones are not excreted in the feces, cell metabolites, or the lungs.
Which hormone is produced by the anterior pituitary gland? -Corticotropin-releasing hormone (CRH) -Norepinephrine -Oxytocin -Growth hormone (GH)
Growth hormone (GH) 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.
When hypofunction of an endocrine organ is suspected, which type of diagnostic test can be administered to measure and assess target gland response? -Hormone stimulation -Antibody binding -24-hour urine -Agglutination
Hormone stimulation Stimulating hormone can be given to identify (determine hypofunction) if the target gland is able to increase hormone response to increased stimulation. Agglutination with enzymes is a way of measuring hormone antigen levels. The 24-hour urine sample measures hormone metabolite excretion. Radioactive hormone-antibody binding levels provide a method of measuring plasma levels.
Which gland acts as a signal-relaying bridge between multiple body systems and the pituitary gland? -Posterior pituitary -Hypothalamus -Thyroid -Parathyroid
Hypothalamus 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.
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? -Dopamine insufficiency -Calcium insufficiency -Hypothyroidism -Hypoglycemia
Hypothyroidism 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.
Which gland is often referred to as the master gland because it secretes many hormones? -Pancreas -Thyroid -Hypothalamus -Pituitary
Pituitary The pituitary gland has been called the master gland because its hormones control the functions of many target glands and cells. That is not a term used to refer to the other options.
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? -Growth hormone (GH) -Prolactin -Corticotropin-releasing hormone (CRH) -Oxytocin
Prolactin 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.
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 -The cytokine-interleukin regulatory mechanism -Basal metabolic rate -The angiotensin I to angiotensin II to aldosterone system
The hypothalamic-pituitary-target cell system 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.
Imaging has proven useful in both the diagnosis and follow-up of endocrine disorders. Two types of imaging studies are useful when dealing with endocrine disorders: Isotopic imaging and non-isotopic imaging. What is an example of isotopic imaging? -Renal angiography -MRI -Thyroid scan -PET scan
Thyroid scan Isotopic imaging includes radioactive scanning of the thyroid. The other answers are all examples of non-isotopic imaging.
While reviewing the major actions of follicle-stimulating hormone (FSH), the faculty points out that in males this hormone is responsible for the: -sperm production. -testosterone levels. -size of gonads. -size of muscles.
sperm production FSH in males stimulates sperm production. GH stimulates growth of bone and muscle. LH stimulates secretions of testosterone. Androgens affect the development of male sex organs.
A client with many nonspecific complaints has been ordered a positron emission tomography (PET) scanning for evaluation of: -tumors located on the endocrine glands. -radioactivity of the thyroid gland. -bone density. -the pancreas response to an insulin injection.
tumors located on the endocrine glands Positron emission tomography (PET) scanning is being used more widely for evaluation of endocrine tumors. PET scans do not calculate the pancreas response to insulin. A DEXA is used for diagnosis and monitoring of osteoporosis (bone density). Isotopic imaging includes radioactive scanning of the thyroid (using radioiodine) and parathyroids.
The nurse cares for a client with severe chronic obstructive pulmonary disease who has been taking oral steroids for several years. Which response in the client's endocrine control will the nurse expect? -Suppression of the client's hypothalamic-pituitary-target cell system -Increased levels of adrenocorticotropic hormone (ACTH) -Increased levels of epinephrine and norepinephrine -Suppression of the body's positive feedback mechanisms
-Suppression of the body's positive feedback mechanisms Exogenous forms of hormones (given as drug preparations) can influence the normal feedback control of hormone production and release. One of the most common examples of this influence occurs with the administration of the corticosteroid hormones, which causes suppression of the hypothalamic-pituitary-target cell system that regulates the production of these hormones. Positive feedback control occurs when rising levels of a hormone cause another gland to release a hormone that is stimulating to the first. The steroid will not cause increase in the levels of the hormones.
In an adult with acromegaly, a growth hormone (GH)-secreting tumor is suspected. What diagnostic test would be used for this client? -A GH stimulation test -A GH suppression test -A GH urine assay test -A GH serum assay test
A GH suppression test
Which body systems work with the endocrine system to regulate body functions? Select all that apply. -Central nervous system -Cardiovascular system -Immune system -Gastrointestinal system -Peripheral nervous system
Central nervous system Immune system Peripheral nervous system The central and peripheral nervous systems and the immune system work together with the endocrine system to regulate body functions.
After having a very stressful day in pathophysiology class, the student knows that which hormone (secreted by the adrenal cortex) will help decrease the effects of stress? -Cortisol, a glucocorticoid -Aldosterone, a mineralocorticoid -Dehydroepiandrosterone, an adrenal androgen -Androstenedione, an adrenal androgen
Cortisol, a glucocorticoid Glucocorticoids, mainly cortisol, affect metabolism of all nutrients; regulate blood glucose levels; affect growth; have anti-inflammatory action; and decrease effects of stress. The other hormones do not affect stress levels.
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: -Increased TSH levels -Decreased TSH levels -Increased TRH levels -Decreased TRH levels
Decreased TRH levels 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).
The nurse is caring for a client with a tentative diagnosis of Hashimoto thyroiditis. Which test result does the nurse anticipate will be present in autoimmune thyroiditis? -Positive anti-thyroid peroxidase antibodies -Elevated thyroid stimulating hormone (TSH) -Decreased T3 -Decreased T4
Positive anti-thyroid peroxidase antibodies Blood tests that are routinely measured in endocrine disorders include various autoantibodies. For example, anti-thyroid peroxidase (anti-TPO) antibodies are measured during the initial diagnostic workup and subsequent follow-up of clients with Hashimoto thyroiditis. The other alterations may be present in all types of hypothyroidism.
A client with many nonspecific complaints has been ordered a positron emission tomography (PET) scanning for evaluation of: -the pancreas response to an insulin injection. -bone density. -tumors located on the endocrine glands. -radioactivity of the thyroid gland.
tumors located on the endocrine glands. Positron emission tomography (PET) scanning is being used more widely for evaluation of endocrine tumors. PET scans do not calculate the pancreas response to insulin. A DEXA is used for diagnosis and monitoring of osteoporosis (bone density). Isotopic imaging includes radioactive scanning of the thyroid (using radioiodine) and parathyroids.
How long is the half-life of the hormone aldosterone, which is only 15% protein bound? -25 minutes -6 days -4 hours -10 seconds
25 minutes Aldosterone, which is only 15% protein-bound, has a half-life of only 25 minutes. The higher the percentage of protein binding, the longer the half-life will be.
What is an advantage of assessing hormone levels through collection of a 24-hour urine? -Scheduled urine collections can be difficult to achieve. -It does not require serum collection for an accurate reading. -Results can be accurately assessed even if urine is not preserved correctly. -Accuracy isn't affected if some voiding is not included in the sample.
It does not require serum collection for an accurate reading. Assessment of hormone levels with a 24-hour urine collection is beneficial because it does not require blood sampling.
As part of maintaining homeostasis, why are hormones, secreted by endocrine cells, continuously inactivated? -Free receptor sites -Prevent accumulation -Stimulate production -Absorb metabolic waste
Prevent accumulation 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.
Which type of imaging is preferred to evaluate the bone density of a client with hyperparathyroidism? -Ultrasound -Magnetic resonance imaging (MRI) -Computed tomography (CT) scan -Dual energy x-ray absorptiometry (DXA) scan
Dual energy x-ray absorptiometry (DXA) scan Preferred types of scans for endocrine tissues include MRI of the pituitary gland and hypothalamus, CT scan of the adrenal glands, DXA scan of bone density, and ultrasound of possible nodules of the thyroid gland. Bone density may be decreased in a client with hyperparathyroidism.
Which of the following are examples of amines? Select all that apply. -Growth hormone (GH) -Follicle stimulating hormone (FSH) -Epinephrine -Thyrotropin-releasing hormone (TRH) -Norepinephrine
Epinephrine Norepinephrine The amines include only norepinephrine and epinephrine. The remaining options are classified as peptides.
Which hormone is secreted based on a cyclic rather than a diurnal manner? -Antidiuretic hormone (ADH) -Growth hormone -Follicle-stimulating hormone (FSH) -Adrenocorticotropic hormone (ACTH)
Follicle-stimulating hormone (FSH) Hormone secretion varies widely over a 24-hour period. Some hormones, such as GH and adrenocorticotropic hormone (ACTH), have diurnal fluctuations that vary with the sleep-wake cycle. Others, such as the female sex hormones (e.g., follicle-stimulating hormone [FSH]) are secreted in a complicated cyclic manner. 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.
A nurse caring for a client who has undergone an antithyroid peroxidase (anti-TPO) antibody test with elevated results should be prepared to educate the client about which disease process? -Hyperparathyroidism -Type 2 diabetes -Gigantism -Hashimoto thyroiditis
Hashimoto thyroiditis Diagnosis of Hashimoto thyroiditis is usually made by detecting elevated levels of anti-thyroid peroxidase antibodies (TPOAb) in the serum. Gigantism is diagnosed as an excessive secretion of growth hormone. There may be high levels of insulin-like growth factor 1 (IGF-1), which also stimulates excessive skeletal growth. States of hyperparathyroidism are associated with increased levels of 1,25-(OH)2D3. Parathyroid hormone (PTH) is an important regulator of calcium and phosphate levels in the blood. Diabetes is diagnosed following fasting plasma glucose test level of 126 mg/dL (6.99 mmol/L) or greater. Glycated hemoglobin testing (Hemoglobin A1C) is a test that measures the quantity of a subtype of hemoglobin that has been glycated, meaning glucose molecules have become bound to the hemoglobin molecule. In conditions of hyperglycemia, the A1C level is increased.
A client with hyperthyroidism took aspirin for a headache. Which complications could develop? Select all that apply. -Hyperthermia -Agitation -Tachycardia -Edema -Hyperlipidemia
Hyperthermia Agitation Tachycardia Thyroxine has a normal half-life of approximately 6 days because it is almost completely protein-bound in the blood. Aspirin competes with thyroxine for the protein carrier, causing the released thyroxine to exert its effect all at once. The client could develop a thyroid crisis, called a thyroid storm, with signs and symptoms of tachycardia, hyperthermia, heart failure, angina, agitation, restlessness, and delirium. Hyperlipidemia and edema could occur as a result of hypothyroidism.
An adult client is scheduled for testing of a suspected growth hormone (GH)-secreting tumor. Which result from the glucose suppression test would confirm the condition? -Increased GH secretion -Hyperinsulinemia -Hypoglycemia -Decreased GH levels
Increased GH secretion A suppression test is intended to determine if an organ that is oversecreting will respond to feedback to suppress that hormone. The glucose suppression test is used for an adult with acromegaly from excessive GH production. Normally, glucose would cause a decrease in GH secretion, but there is increased production of GH in response to the glucose in the test when the client has acromegaly.
A client develops hypocalcemia after thyroid surgery. Which hormonal imbalance caused this complication? -Lack of thyrotropic-releasing hormone -Lack of thyroid hormone -Lack of parathyroid hormone -Lack of thyroid-stimulating hormone
Lack of parathyroid hormone The parathyroid glands are located on the posterior side of the thyroid gland. If the parathyroid glands are removed at the same time as the thyroid the client will experience a drop in serum calcium levels.
When trying to explain hypothyroidism to a newly diagnosed client, the nurse stresses the fact that the thyroid hormone is transported in blood by specific: -Prohormones -Proteins -Target cells -Cholesterol molecules
Proteins 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.
Which manifestation would a nurse expect when assessing a child with insufficient growth hormone (GH) secretion? -Rank below 10% on the growth chart -Increased susceptibility to infection -Mental sluggishness -Lower blood calcium levels
Rank below 10% on the growth chart GH stimulates growth of bone and muscle and promotes protein synthesis and fat metabolism and decreased carbohydrate metabolism. A child lacking sufficient GH would demonstrate lack of growth but not the mental delays seen in childhood hypothyroidism.
Hormones are chemical messengers that provide which function in the body? -Transport fatty acids and lipids -Cause one specific tissue effect -Initiate immune reactions -Regulate body functions
Regulate body functions 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.
The kidney produces 1,25-dihydroxyvitamin D. This form of vitamin D is responsible for which action in the body? -Delays intestinal absorption of glucose -Increases the metabolic rate -Stimulates calcium absorption from the intestine -Facilitates movement of calcium into the bone
Stimulates calcium absorption from the intestine 1,25-dihydroxyvitamin D from the kidney stimulates calcium absorption from the intestine. Somatostatin from the pancreas delays intestinal absorption of glucose. Thyroxine (T4) can increase metabolic rate. Growth hormone (GH) stimulates growth of bone and muscle.
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 protect the fetus from effects of forceful contractions -To stimulate contraction of the uterus -To reduce pain of uterine contractions -To contribute to maturation of fetal lungs
To stimulate contraction of the uterus 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.
Cyclic adenosine monophosphate (cAMP) performs which role in the functioning of the endocrine system? -Mediating hormone synthesis by non-vesicle-mediated pathways -Acting as a high-affinity receptor on the surface of target cells -Inactivating hormones to prevent excess accumulation -Acting as a second messenger to mediate hormone action on target cells
Acting as a second messenger to mediate hormone action on target cells 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 nurse is planning to collect a 24-hour urine sample for hormone assay. In which situation does the nurse collaborate with the health care provider to find an alternate type of testing? -Client has hypothyroidism. -Client has diabetes. -Client has anemia. -Client has anuria.
Client has anuria The advantages of a urine test include the relative ease of obtaining urine samples and the fact that blood sampling is not required. The disadvantage is that reliably timed urine collections often are difficult to obtain and rely on adequate renal function. Anuria refers to the absence of urine output.
When sensors detect a change in a hormone level, the hormonal response is regulated by which mechanism that will return the level to within normal range? -Action potential -Production -Feedback -Metabolic
Feedback Feedback (negative and sometimes positive) mechanisms respond to levels that are too high or too low. The level of many of the hormones in the body is regulated by negative feedback mechanisms. The function of this type of system is similar to that of the thermostat in a heating system. For example, when the sensors detect a decrease in blood levels, they initiate changes that cause an increase in hormone production. Metabolic responses and increased/decreased production occur as a consequence of hormone level fluctuations, not as a regulating mechanism. Action potential is not a regulating mechanism for this function.
Which hormone is produced by the anterior pituitary gland? -Growth hormone (GH) -Norepinephrine -Corticotropin-releasing hormone (CRH) -Oxytocin
Growth hormone (GH) 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.
Which physiologic process allows hormones to exert influence upon some cells and not others? -Pituitary-hypothalamic feedback -Hormone receptors -Protein binding -Positive feedback
Hormone receptors Hormone receptors are complex molecular structures (usually proteins) that are located either on the cell surface or inside target cells. The structure of these receptors is specific to a particular hormone, which allows target cells to respond to one hormone and not to others. For example, receptors in the thyroid are specific for thyroid-stimulating hormone, and receptors on the gonads respond to the gonadotropic hormones. Positive feedback control occurs when rising levels of a hormone cause another gland to release a hormone that is stimulating to the first. Protein binding describes the ability of proteins to form bonds with other substances. Pituitary-hypothalamic feedback describes negative feedback.
Which statement best explains the function of hormone receptors? -Hormone receptors respond to decreasing hormone levels by producing a decrease in receptor numbers. -Hormone receptors are located within the red blood cells and carry hormones to the target cells. -Hormone receptors recognize a specific hormone and translate the hormonal signal into a cellular response. -Hormone receptors produce antibodies to block certain hormones from entering the cell.
Hormone receptors recognize a specific hormone and translate the hormonal signal into a cellular response. 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.
Release and synthesis of anterior pituitary hormones are mainly regulated by which part of the body? -Adrenal gland -Cell receptors -Hypothalamus -Thymus gland
Hypothalamus The hypophysis (pituitary plus hypothalamus) and hypothalamus stimulatory hormones regulate the release and synthesis of anterior pituitary hormones. The adrenal gland and thymus gland hormones are regulated by the hypothalamus. Cell receptors are involved with the target cell response to the hormones.
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? -Cerebellum -Anterior pituitary -Cerebral cortex -Hypothalamus
Hypothalamus 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, and the cerebral cortex is associated with sensory, motor, and association.
The nurse is discussing positive feedback mechanisms. Which example best explains this mechanism? -Increased glucose levels in the blood decreases growth hormone (GH) levels. -Decreased thyroid hormone (TH) increases thyroid-stimulating hormone (TSH) levels. -Decreased cortisone levels increase blood levels of adrenocorticotropic hormone (ACTH). -Increased estradiol production causes increased follicle-stimulating hormone (FSH) production.
Increased estradiol production causes increased follicle-stimulating hormone (FSH) production. 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.
What is the most common mechanism of hormone control? -Hypothalamic-pituitary-adrenal axis -Hypothalamic-pituitary-target cell feedback -Negative feedback -Positive feedback
Negative feedback With negative feedback, the most common mechanism of hormone control, some feature of hormone action directly or indirectly inhibits further hormone secretion so that the hormone level returns to an ideal level or set point.
A nursing instructor is teaching a group of students about the action of hormones. The instructor determined that teaching was effective when the students recognize the local action of hormones as: -Hormonal -Paracrine -Autocrine -Pancreatic
Paracrine When hormones act locally on cells other than those that produced the hormone, the action is called paracrine. Hormones can also exert an autocrine action on the cells in which they were produced. Pancreatic and hormonal are not actions.
Select the most accurate statement regarding measurements of urinary hormone. -Drugs will not alter testing results. -Requires blood and urine sampling. -Discarded samples will not alter results. -Provide a better measure of hormone levels during a designated period.
Provide a better measure of hormone levels during a designated period. Measurements of urinary hormone or hormone metabolite excretion often are done on a 24-hour urine sample and provide a better measure of hormone levels during that period than hormones measured in an isolated blood sample. The advantages are relative ease of obtaining urine samples and blood sampling is not required. 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 interfere with the test results.
Which type of characteristic do thyroid and steroid hormones exert on target cells by way of nuclear receptors? -The selective use of a second messenger -Both lipid solubility and water solubility -The ability to cross the cell membrane of target cells -The ability to regulate surface receptor affinity
The ability to cross the cell membrane of target cells Hormones that utilize nuclear receptors enter the target cell (i.e., cross the cell membrane) and bind to receptors in the cell nucleus that are gene regulatory proteins. These hormones do not selectively utilize second messengers, and they do not interact with surface receptors. They are not both lipid- and water-soluble.
Which physiologic process best exemplifies a positive feedback mechanism? -The regulation of blood glucose levels by insulin -The release of parathyroid hormone in response to decreased serum calcium levels -The increase in prolactin secretion that occurs with more frequent breast-feeding -The release of antidiuretic hormone when sodium levels are higher than normal
The increase in prolactin secretion that occurs with more frequent breast-feeding A positive feedback mechanism occurs when one hormonal or physiologic factor stimulates further hormonal release, creating a cascade that will increase until corrected. Correction of alterations in homeostasis is normally achieved using negative feedback mechanisms, such as those accomplished by insulin, parathyroid hormone, and antidiuretic hormone.
While discussing the elimination of hormones from the body to prevent overaccumulation, which hormones are eliminated in bile? Select all that apply. -Peptide hormones -Unbound adrenal hormones -Catecholamines -Gonadal steroid hormones -Thyroid hormones
Unbound adrenal hormones Gonadal steroid hormones Thyroid hormones Steroid hormones are bound to protein carriers for transport and are inactive in the bound state. Unbound adrenal and gonadal steroid hormones are conjugated in the liver, which renders them inactive, and then excreted in the bile or urine. Thyroid hormones also are transported by carrier molecules. The free hormone is rendered inactive by the removal of amino acids in the tissues, and the hormone is conjugated in the liver and eliminated in the bile. The catecholamine production is measured by some of their metabolites. In general, peptide hormones also have a short lifespan in the circulation. Their major mechanism of degradation is through binding to cell surface receptors, with subsequent uptake and degradation by peptide-splitting enzymes in the cell membrane or inside the cell.
Sometimes the measurement of hormones is done through a urine sample. What is an advantage of measuring hormone levels through a urine sample rather than a blood sample? -Urine samples are easily obtained. -There are more hormone metabolites in urine than in blood. -Blood sampling has more pure hormone than urine does. -Urine has more accurate measurements of hormones.
Urine samples are easily obtained
A client is scheduled for a suppression test as part of the diagnostic testing for his suspected endocrine disorder. The results of this test will help the care team determine: -if the client's hypothalamus is functioning correctly. -if a target endocrine gland is capable of hormone production. -whether the client is producing excessive hormone levels. -whether the client's pituitary gland is functioning normally.
whether the client is producing excessive hormone levels. Suppression tests are used when hyperfunction of an endocrine organ is suspected. Suppression tests are not used to gauge pituitary or hypothalamus function. Stimulation tests are used to rule out hypofunction of an endocrine organ.
The endocrine system is closely linked with the nervous system. What neurotransmitter can also act as a hormone? -Norepinephrine -Dopamine -Succinylcholine -Epinephrine
-Epinephrine Neurotransmitters such as epinephrine can act as neurotransmitters or as hormones.
What is the role of glucagon in initiating the breakdown of glycogen? -First messenger -Intracellular catalyst -Receptor antagonist -Second messenger
-First messenger Glucagon acts on the surface receptors of liver cells as first messenger. Glucagon starts the process of glycogen breakdown by signaling the intracellular signal system, called the second messenger.
When comparing the endocrine and nervous system functions, the nurse knows that the endocrine system: Select all that apply. -takes longer to respond to innervations but has prolonged actions when they arrive. -sends signals to neurons over a short distance to muscles. -responds to neurotransmitter molecules within milliseconds. -glands are widely scattered throughout the body. -releases hormones into the blood that is transported throughout the body.
-takes longer to respond to innervations but has prolonged actions when they arrive. -releases hormones into the blood that is transported throughout the body. -glands are widely scattered throughout the body. The endocrine system uses chemical messengers called hormones as a means of controlling the flow of information between the different tissues and organs of the body. It does not act alone, however, but interacts with the nervous system to coordinate and integrate the activity of body cells. 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. The endocrine system uses hormones released into the blood and transported throughout the body to influence the activity of body tissues. Tissue and organ responses to endocrine hormones tend to take much longer than the response to neurotransmitters, but once initiated, they tend to be much more prolonged than those induced by the nervous system. The glands of the endocrine system are widely scattered throughout the body.
The nurse is assessing a client with thyrotoxicosis and the nurse is explaining how the thyroid gland is stimulated to release thyroid hormones. The nurse should describe what process? -Direct neural stimulation -Homeostatic receptors on surface of gland -Action of releasing hormones from hypothalamus -Steady-state continuous release
Action of releasing hormones from hypothalamus The synthesis and release of anterior pituitary hormones are largely regulated by the action of releasing or inhibiting hormones from the hypothalamus, which is the coordinating center of the brain for endocrine activity such as thyroid activity. There are no direct innervations for hormone release from the thyroid gland, and homeostatic receptors do not exist. Steady-state release of hormones does not occur.
Hormones can be synthesized by both vesicle-mediated pathways and non-vesicle-mediated pathways. What hormones are synthesized by non-vesicle-mediated pathways? -Pepsin and ghrelin -Neurotransmitters that are also hormones -Renin and angiotensin -Androgens and estrogens
Androgens and estrogens Hormones that are synthesized by non-vesicle-mediated pathways include the glucocorticoids, androgens, estrogens, and mineralocorticoids—all steroids derived from cholesterol.
A client experiences an increase in cortisol as a result of Cushing disease. Which hormonal responses demonstrate the negative feedback mechanism? -Decreased thyroid-stimulating hormone (TSH) -Increased thyrotropin-releasing hormone (TRH) -Increased follicle-stimulating hormone (FSH) -Decreased adrenocorticotropic hormone (ACTH)
Decreased adrenocorticotropic hormone (ACTH) Negative feedback occurs when secretion of one hormone causes a reduction in the secretion of the hormone that stimulates production of the first hormone. In this case, ACTH manufactured by the anterior pituitary gland would normally stimulate the release of cortisol, but with the increase of cortisol produced by the secreting tumor, enough cortisol already floods the system that there should be a reduction in the ACTH level.
A client experiences an increase in cortisol as a result of Cushing disease. Which hormonal responses demonstrate the negative feedback mechanism? -Increased follicle-stimulating hormone (FSH) -Increased thyrotropin-releasing hormone (TRH) -Decreased thyroid-stimulating hormone (TSH) -Decreased adrenocorticotropic hormone (ACTH)
Decreased adrenocorticotropic hormone (ACTH) Negative feedback occurs when secretion of one hormone causes a reduction in the secretion of the hormone that stimulates production of the first hormone. In this case, ACTH manufactured by the anterior pituitary gland would normally stimulate the release of cortisol, but with the increase of cortisol produced by the secreting tumor, enough cortisol already floods the system that there should be a reduction in the ACTH level.
A client experiences an increase in thyroid hormone as a result of a thyroid tumor. Which hormonal response demonstrates the negative feedback mechanism? -Increased follicle-stimulating hormone (FSH) -Increased thyrotropin-releasing hormone (TRH) -Decreased adrenocorticotropic hormone (ACTH) -Decreased thyroid-stimulating hormone (TSH)
Decreased thyroid-stimulating hormone (TSH) Negative feedback occurs when secretion of one hormone causes a reduction in the secretion of the hormone that stimulates production of the first hormone. In this case, TSH, which is manufactured by the anterior pituitary gland, would normally stimulate release of thyroid hormones, but with the increase of those hormones by the secreting tumor, enough thyroid hormones flood the system that there should be a reduction in TSH levels.
An adult client presents to the emergency department after an episode of syncope. Blood pressure is low and the pulse is thready and rapid. The client frequently voids large amounts of pale, clear urine. Lung sounds are clear and skin turgor is inelastic. Which endocrine disorder is the likely cause of these manifestations? -Hyperparathyroidism -Diabetes insipidus -Gigantism -Myxedema
Diabetes insipidus Normally, antidiuretic hormone (ADH) from the posterior pituitary gland causes the renal tubule to reabsorb water and sodium. When too little ADH is secreted, the client will lose large amounts of fluid and become dehydrated. Despite fluid volume deficit, the urine output will be dilute and in large amounts. In hyperparathyroidism, the client will have an elevated blood calcium level and cardiac dysrhythmias. Fluid volume will remain stable, but the client may develop renal calculi. In myxedema, lack of thyroid hormones causes the client to become sluggish. Urinary output remains normal. Gigantism results from excess production of growth hormone in children and results in large body size. It does not influence urine output.
A nurse examines the laboratory values of a client in heart failure. Which value indicates a compensatory hormone mechanism? -Elevated atrial natriuretic hormone -Decreased red blood cell count -Decreased hematocrit -Elevated serum pH
Elevated atrial natriuretic hormone In heart failure, the client experiences fluid backlog in the heart as venous blood continues to return, but cardiac output is reduced. This stretches the atria, which secrete atrial natriuretic hormone (or peptide) to stimulate vasodilation and increased renal excretion of sodium and water. This reduces the volume and the strain in the heart.
Which manifestation would the nurse observe when assessing a client diagnosed with a benign secreting tumor of the adrenal medulla? -Elevated catecholamine levels and tachycardia -Increased aldosterone and fluid retention -Rising thyroid hormone and insomnia -Enhanced estrogen levels and breast enlargement
Elevated catecholamine levels and tachycardia The adrenal medulla secretes the neurotransmitters epinephrine (adrenalin) and norepinephrine (a precursor to epinephrine). A secreting tumor will cause the client to experience manifestations of sympathetic stimulation, such as episodic anxiety, tachycardia, and hypertension. A tumor of the adrenal medulla will not impact thyroid or aldosterone secretion.
Which statements concerning endocrinology laboratory testing are true? Select all that apply. -Endocrine tests are a good substitute for a client-focused physical assessment. -Client education regarding endocrine testing must include specific test requirements. -Currently there are few diagnostic tests used for endocrine disorders. -Endocrine testing is flexible regarding collection techniques and practices. -Endocrine tests are generally sensitive to storage requirements.
Endocrine tests are generally sensitive to storage requirements. Client education regarding endocrine testing must include specific test requirements. The field of endocrinology is one of the most laboratory-dependent specialties in health care. However, a few guiding principles should be considered when approaching endocrine studies and disorders. No endocrine test is a substitute for a good physical examination and medical history. The person must be seen as a whole person, which includes many complex factors. One vital component to endocrine testing of any kind is strict adherence to all procedure and test requirements. The possibility of error is always present and the quality of any endocrine test is only as good as the quality of the specimen presented for testing. Client education regarding test preparation, timing, collection procedure and storage are critical and will be discussed in relation to the specific test.
Which type of hormones are released as soon as they are synthesized? -Amino acid hormones -Protein hormones -Lipid-soluble steroid hormones -Polypeptide hormones
Lipid-soluble steroid hormones Protein and polypeptide hormones are synthesized and stored in vesicles in the cytoplasm of the cell until secretion is required. Other hormones, such as the lipid-soluble steroid hormones, are released as they are synthesized. The amines and amino acid hormones, includes norepinephrine and epinephrine, are derived from a single amino acid.
While discussing the regulation of hormone levels, the instructor gives an example of hormones regulated by feedback mechanisms. Which example of this regulation is best? -Following a meal that was high in carbohydrates, a person's blood glucose elevates, which stimulates the release of insulin from the pancreas. -When a person's body pH is decreasing, the stomach lining becomes more acidic to offset this. -When a female is thinking about getting pregnant, the body knows to release female sex hormones in greater proportion than usual. -In children, the body knows to release growth hormones while they are sleeping instead of when they are awake and running around.
Following a meal that was high in carbohydrates, a person's blood glucose elevates, which stimulates the release of insulin from the pancreas. 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. None of the other examples are accurate examples of this feedback mechanism.
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? -Target -Stored -Self -Local
Local 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.
The hormone levels in the body need to be kept within an appropriate range. How is this accomplished for many of the hormones in the body? -Regulated feedback loop -Positive feedback loop -Sensory feedback loop -Negative feedback loop
Negative feedback loop The level of many of the hormones in the body is regulated by negative feedback mechanisms.
A teen with newly diagnosed pituitary dwarfism asks the nurse why growth hormone must be taken as an injection rather than a pill like the steroids used for arthritis. Which response best answers the client's question? -Peptide proteins will be digested instead of entering the bloodstream. -Hormones that are cholesterol-derived are unaffected by digestion. -Amino acid-based hormones will directly enter the bloodstream from the gastrointestinal tract. -Autocrine effects of hormones influence the cells that produce them.
Peptide proteins will be digested instead of entering the bloodstream. Although each of the foregoing statements about hormones is true, only one directly answers the client's question. Hormones can be placed into three categories according to structure: Amines and amino acids are the first group and include, epinephrine, and the thyroid hormones. The second group contains most of the hormones and consists of peptides and proteins. The third group is steroids that are made from cholesterol. These hormones are not degraded by the gastrointestinal enzymes. Growth hormone is a large protein in the class of peptides and proteins—the group with bonds that can be digested in the gastrointestinal tract.
A client receives steroids for several months to treat an inflammatory condition. Which action by the primary health care provider indicates an understanding of the negative feedback mechanism when the client no longer needs the medication? -Measuring urine catecholamine levels before stopping the drug -Instructing the client to stop taking the medication -Prescribing a tapering dose of the medication over weeks -Scheduling a positron emission tomography scan a week after stopping the drug
Prescribing a tapering dose of the medication over weeks Negative feedback occurs when secretion of one hormone causes a reduction in the secretion of the hormone that stimulates production of the first hormone. In this case, adrenocorticotropic hormone (ACTH) manufactured by the anterior pituitary would normally stimulate release of cortisol, but with the increase of cortisol produced by the secreting tumor, enough cortisol already floods the system that there should be a reduction in the ACTH level. Sudden withdrawal of the medication would leave the client without glucocorticoids and risk an Addisonian crisis. Gradual withdrawal of the medication allows the pituitary to measure the drop in cortisol levels and begin secreting ACTH.
The nurse is caring for a client who is receiving exogenous corticosteroids for rheumatoid arthritis. Recognizing that hormone levels are regulated by negative feedback, which laboratory test result does the nurse anticipate uncovering when reviewing the medical record? -Increase in ACTH -Reduction in TSH -Reduction in ACTH -Increase in TSH
Reduction in ACTH The function of the negative feedback system is similar to that of the thermostat in a heating system. When the sensors detect a decrease in hormone levels, they initiate changes that cause an increase in hormone production. When hormone levels rise above the set point of the system, the sensors cause hormone production and release to decrease, driving the stimulating hormone down.
A client with hyperthyroidism is being treated with medication that blocks the activity of thyroid-stimulating hormone. Her care team has determined that she has been overproducing TSH. This client will have lost her ability to: -have positive feedback regulation. -metabolize TSH. -have negative feedback regulation. -metabolize thyroxin.
have negative feedback regulation. When the sensors detect a decrease in hormone levels, they initiate changes that cause an increase in hormone production; when hormone levels rise above the set point of the system, the sensors cause hormone production and release to decrease. Positive feedback increases activity rather than shuts if off. Metabolism of the hormone is not an issue in regulation.
A middle-aged female client has been diagnosed with a thyroid condition. The nurse educates the client about the prescription and needed follow-up lab work, which will help regulate the dosage. The client asks, "Why do I not return to the clinic for weeks, since I am starting the medication tomorrow morning?" The nurse bases the answer on the knowledge that thyroid hormones: -may take days for the full effect to occur, based on the mechanism of action. -cause many side effects, and the clinic wants the client to be on the medication for several weeks so that all the effects can be reported. -will begin working right away, and the clinic wants to see how the body is responding to the drug. -can cause weight loss, so the clinic wants to see how much weight the client loses at the return visit.
may take days for the full effect to occur, based on the mechanism of action. Hormones produce their effects through interaction with high-affinity receptors, which in turn are linked to one or more effector systems within the cell. These mechanisms involve many of the cell's metabolic activities, ranging from ion transport at the cell surface to stimulation of nuclear transcription of complex molecules. The rate at which hormones react depends on their mechanism of action. Thyroid hormone, which controls cell metabolism and synthesis of intracellular signaling molecules, requires days for its full effect to occur. None of the other distractors are accurate reasons to have the client return to the clinic weeks after starting the medication.
During a near-miss accident while cycling, a client marvels at how fast he was able to react. He attributes this to his "fight or flight" response but then wonders why it lasts for only a short period. The client had a short burst of catecholamine activity because catecholamines are: -consumed as fuel at the site of action. -bound to transport proteins that will limit their function in circulation. -rapidly degraded by enzymes in circulation and at the tissue. -naturally inactivated by exposure to systemic circulation.
rapidly degraded by enzymes in circulation and at the tissue. Most peptide hormones and catecholamines are water soluble and circulate freely in the blood, where they are degraded by enzymes and excreted by the kidneys and liver. Catecholamines are rapidly degraded by catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO). There is no breakdown by just being in circulation. Hormones are not used as fuel. Water-soluble hormones such as catecholamines are not bound to proteins.
In major athletic competition, athletes are required to submit to liquid chromatography testing looking for: -blood doping to increase RBC levels. -low serum sodium levels indicating dehydration. -use of opioids to minimize pain during competition. -use of performance-enhancing agents to increase the chances of winning.
use of performance-enhancing agents to increase the chances of winning. 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).
