Patho chapter 31

A 51 year-old woman has been experiencing signs and symptoms of perimenopause and has sought help from her family physician. A deficiency in estrogen levels has been determined to be a contributing factor. Which of the following phenomena could potentially underlie the woman's health problem?

Insufficient estrogen production within the smooth endoplasmic reticulum of the relevant cells. Explanation: Steroids such as estrogen are produced in the smooth endoplasmic reticulum. Synthesis and release are not separate processes as in the case of peptide hormones and prohormones are associated with peptides, polypeptides and proteins hormones.

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?

"A single hormone can act on not only one process or organ but often on several different locations or processes." Explanation: 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.

When explaining about structural classifications to a group of students, the instructor discusses the peptides and proteins. They talk about small hormones and hormones as large and complex as growth hormone (GH) which has approximately how many amino acids involved?

200 amino acids. Explanation: Growth hormone is very large and complex protein which has ~ 200 amino acids.

A patient exhibiting problems with their thyroid has been scheduled for a radioactive scan. From the following list of patients, which would the nurse question as to whether this would be a safe procedure for this patient?

A young female patient who has been trying to get pregnant. Explanation: Radioactive iodine therapy is contraindicated in pregnant women because 131I crosses the placenta and can adversely affect the fetal thyroid gland. The other clients would have no contraindication to the substance.

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.

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 Explanation: 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.

A patient experiences an increase in thyroid hormone as a result of a thyroid tumor. Which of the following hormonal responses demonstrates the negative feedback mechanism?

Decreased thyroid-stimulating hormone (TSH) Explanation: 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.

A nurse examines the laboratory values of a patient in heart failure. Which of the following values indicates a compensatory hormone mechanism?

Elevated atrial natriuretic hormone Explanation: In heart failure, the patient 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 of the following manifestations would the nurse observe when assessing a patient diagnosed with a pheochromocytoma of the adrenal medulla?

Elevated catecholamine levels and tachycardia Explanation: The adrenal medulla secretes the neurotransmitters epinephrine (adrenalin) and norepinephrine (a precursor to epinephrine). A secreting tumor will cause the patient 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.

The endocrine system is closely linked with the nervous system. What neurotransmitter can also act as a hormone?

Epinephrine Explanation: Neurotransmitters such as epinephrine can act as neurotransmitters or as hormones. The other answers are not correct.

Which of the following is the role of glucagon in initiating the breakdown of glycogen?

First messenger Explanation: 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.

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. Explanation: 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.

Select the statement that best explains the function of hormone receptors.

Hormone receptors recognize a specific hormone and translate the 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. The other choices are not true.

The hypophysis is a unit formed by the pituitary and the hypothalamus. These two glands are connected by the blood flow in what system?

Hypophyseal portal system Explanation: The hypothalamus and pituitary (i.e., hypophysis) form a unit that exerts control over many functions of several endocrine glands as well as a wide range of other physiologic functions. These two structures are connected by blood flow in the hypophyseal portal system, which begins in the hypothalamus and drains into the anterior pituitary gland, and by the nerve axons that connect the supraoptic and paraventricular nuclei of the hypothalamus with the posterior pituitary gland. The other answers are not correct.

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, ?-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 adult patient is scheduled for testing of a suspected growth hormone (GH)- secreting tumor. Which of the following results from the glucose suppression test would confirm the condition?

Increased GH secretion Explanation: 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 patient has acromegaly.

Which of the following statements is correct about hormone transport? Select all that apply.

Insulin is unbound. Glucocorticoids are bound. Prolactin is unbound. Explanation: Steroids and thyroid hormone are transported bound to carrier molecules. Peptides and protein hormones such as insulin, glucagon, parathyroid hormone, prolactin, and ACTH usually circulate unbound.

Neurotransmitters like catecholamines (ex. dopamine and epinephrine) have a reaction time of:

Milliseconds. Explanation: The neurotransmitters, which control the opening of ion channels, have a reaction time of milliseconds.

What is the most common mechanism of hormone control?

Negative feedback Explanation: 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.

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?

Negative feedback loop

Which of the following hormones will elicit a more rapid response than the others?

Norepinephrine Explanation: Neurotransmitter hormones open ion channels and produce extremely rapid responses, whereas peptides and proteins change cell metabolism over a period of days.

Which gland is often referred to as the master gland because it secretes many hormones?

Pituitary Explanation: 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.

The nurse is caring for a client with a tentative diagnosis of Hashimoto thyroiditis. Which of these test results does the nurse anticipate will be present in autoimmune thyroiditis?

Positive anti-thyroid peroxidase antibodies Explanation: 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 followup of patients with Hashimoto thyroiditis. The other alterations may be present in all types of hypothyroidism.

While reviewing the concept of nuclear receptors with a group of pathophysiology students, the instructor uses the example of clients with type 2 diabetes mellitus taking pioglitazone, a thiazolidinedione medication. Because of the peroxisome proliferator-activated receptors (PPARs), the drug has which effect on the clients' diabetes? Select the best answer.

Promote glucose uptake and increase the synthesis of certain proteins involved in fat metabolism, which reduces levels of certain types of lipids. Explanation: The peroxisome proliferator-activated receptors (PPARs) bind intracellular lipid metabolites and regulate the transcription of genes involved in lipid metabolism and adipose tissue metabolism. Pioglitazone is not given solely to increase metabolic rate or to just burn fats, even though this may occur. Thiazolidimedione medications lower insulin resistance in muscle and fat. They also reduce glucose produced by the liver.

Select the most accurate statement regarding measurements of urinary hormone:

Provide a better measure of hormone levels during a designated period. Explanation: 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.

Select the process that allows hormones to exert influence upon some cells and not others.

Receptor binding Explanation: Receptor binding is a process that 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.

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 21 year-old female is suspected of having inadequate function of her hypothalamic-pituitary-thyroid system. Her care provider is planning to inject thyrotropin-releasing hormone (TRH) and then measure her levels of TSH. Which of the following diagnostic tests is being performed?

Stimulation test Explanation: A stimulation test involves the introduction of an element that stimulates the production of another factor or hormone followed by measurement of that hormone. This is not the case in a suppression test, RIA test of metabolite excretion test.

A client who is referred to the endocrinologist's office for an evaluation of his hormone levels asks what regulates the hormone levels. The best response would be that hormone levels in the body are primarily regulated by:

The hypothalamic-pituitary-target cell system Explanation: The levels of many of the hormones are regulated by feedback mechanisms that involve the hypothalamic-pituitary-target cell system. Positive feedback control refers to rising levels of a hormone that causes another gland to release a hormone that is stimulating to the first. The hypophyseal portal system connects the supraoptic and paraventricular nuclei of the hypothalamus with the posterior pituitary gland. Exogenous forms of hormones (given as drug preparations) can influence the normal feedback control of hormone production and release.

The nurse is teaching a client who has been newly diagnosed with hypothyroidism about the function of the thyroid. Which of these does the nurse explain to the client is the role of the thyroid gland?

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.

The nurse administers a glucocorticoid medication to a client with pneumonia. Which of these does the nurse teach the client is the purpose of the medication?

To decrease airway inflammation Explanation: Glucocorticoids affect metabolism of all nutrients and have anti-inflammatory effects, which can assist with airway inflammation.

The physician is assessing a client with a preliminary diagnosis of endocrine disorder. Further assessment findings identify abnormalities with emotion, pain, body temperature, and neural input. The physician determines the need to further assess the:

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 physiological 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.

A patientreceives steroids for several months to treat an inflammatory condition. Which of the following actions by the primary healthcare provider indicates an understanding of the negative feedback mechanism when the patient no longer needs the medication?

Prescribing a tapering dose of the medication over weeks Explanation: 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 already floods the system there has been a reduction in ACTH levels. Sudden withdrawal of the medication would leave the patient 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.

A middle-aged female client has been diagnosed with 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. Explanation: 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.