Pathophysiology Chapter 40
Which hormone is produced by the anterior pituitary gland? Oxytocin Norepinephrine Corticotropin-releasing hormone (CRH) Growth hormone (GH)
D 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 structure controls the functions of the greatest number of target glands and cells? Pituitary gland Pancreas Thyroid gland Adrenal cortex
A The pituitary gland has been called the master gland because its hormones control the functions of many target glands and cells. It supersedes the importance of the thyroid, adrenal cortex, or pancreas in this regulatory role.
Which complications could occur when an adult client has a secreting tumor of the anterior pituitary gland that results in excess hormone production? Select all that apply. Diabetes mellitus Hypothyroidism Acromegaly Addison disease Metrorrhagia
ACE Explanation: The adenohypophysis secretes the following: (1) thyroid stimulating hormone that causes thyroid hormone production, as well as luteinizing hormone and follicle-stimulating hormone that produce the female reproductive cycle; (2) adrenocorticotrophic hormone to stimulate glucocorticoid production from the adrenal cortex; (3) growth hormone to stimulate cell growth and moderate metabolism; and (4) prolactin to stimulate breasts for breast feeding. Excess secretion of these hormones would produce hyperthyroidism, excessive menstruation, and acromegaly. Diabetes mellitus could develop if the resultant Cushing disease remains untreated for some time.
Which manifestation would a nurse expect when assessing a child with insufficient growth hormone (GH) secretion? Increased susceptibility to infection Lower blood calcium levels Rank below 10% on the growth chart Mental sluggishness
C 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.
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? autocrine local mediation endocrine paracrine
C 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.
Which hormone requires a carrier protein for transport through the blood? Growth hormone Insulin Parathormone Cortisol
D Specific carrier proteins synthesized in the liver carry steroid hormones such as cortisol and thyroid hormone. The other listed options are peptide hormones and protein hormones that are water soluble and usually circulate unbound in the blood.
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? Oxytocin Corticotropin-releasing hormone (CRH) Growth hormone (GH) Prolactin
D 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.
A client has developed a tumor of the posterior pituitary gland. The client is at risk for problems with secretions of: Adrenocorticotropic hormone (ACTH) and vasopressin Somatostatin and prolactin Growth hormone-releasing hormone (GHRH) and dopamine Antidiuretic hormone (ADH) and oxytocin
D The posterior pituitary secretes ADH and oxytocin/vasopressin, while the anterior pituitary secretes the hormones listed in the other choices.
A nurse has just completed client education on how hormones are normally regulated by feedback mechanisms. The client asks, "What, if anything, can alter the regulation of anterior pituitary hormones?" Which response by the nurse would be considered an appropriate reply? Select all that apply. Nutritional status Stress Temperature Weight Age Genetics
ABC The release of anterior pituitary hormones comes from the hypothalamus, which 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 (like stress), pain, and body temperature are communicated to the endocrine system. Genetics, weight, and age will not influence response.
The endocrine system is closely linked with the nervous system. Which neurotransmitter can also act as a hormone? epinephrine norepinephrine progesterone thyroid-stimulating hormone
A Neurotransmitters such as epinephrine can act as neurotransmitters or as hormones and are referred to as neurohormones. Other examples include dopamine, oxytocin, and somatostatin. Thyroid stimulating hormone, progesterone, and norepinephrine do not act as neurotransmitters.
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." "A single hormone can act on not only one process or organ but often on several different locations or processes." "Sometimes hormones act locally on the area where they were produced, as in the case of endocrine actions." "It's uncommon for production of hormones to be far removed from the tissue where they ultimately exert their effect."
B 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.
A client has received an injection containing thyrotropin-releasing hormone (TRH) and is now being assessed for serum levels of thyroid-stimulating hormone (TSH). Which type of diagnostic testing is this client undergoing? Autoantibody testing Radioimmunoassay (RIA) Stimulation testing Suppression testing
C Introduction of TRH tests the pituitary gland's ability to produce TSH, and is an example of a stimulation test. Suppression testing examines a gland's response to a stimulus that would normally result in decreased hormone production. RIA and autoantibody testing are examples of direct and indirect measurement of serum levels of a hormone.
When discussing luteinizing hormone and follicle-stimulating hormone with students, the instructor will emphasize that these hormones are under the control of: Thyroid gland Pancreas Posterior adrenal cortex Anterior pituitary gland
D Explanation: The pituitary gland has been called the master gland because its hormones control the functions of many target glands and cells. 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.
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? Blood sampling has more pure hormone than urine does. Urine has more accurate measurements of hormones. There are more hormone metabolites in urine than in blood. Urine samples are easily obtained.
D The advantages of a urine test include the relative ease of obtaining urine samples and the fact that blood sampling is not required.
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? Prescribing a tapering dose of the medication over weeks Instructing the client to stop taking the medication Measuring urine catecholamine levels before stopping the drug Scheduling a positron emission tomography scan a week after stopping the drug
A 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.
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 Self Stored Target
A 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.
Which gland is often referred to as the master gland because it secretes many hormones? Pituitary Thyroid Hypothalamus Pancreas
A 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.
What is the most common mechanism of hormone control? Negative feedback Hypothalamic-pituitary-target cell feedback Positive feedback Hypothalamic-pituitary-adrenal axis
A 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.
As part of maintaining homeostasis, why are hormones, secreted by endocrine cells, continuously inactivated? Stimulate production Prevent accumulation Absorb metabolic waste Free receptor sites
B 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.
Release and synthesis of anterior pituitary hormones are mainly regulated by which part of the body? Thymus gland Hypothalamus Cell receptors Adrenal gland
B Explanation: 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.
Hormones can be synthesized by both vesicle-mediated pathways and non-vesicle-mediated pathways. What hormones are synthesized by non-vesicle-mediated pathways? Renin and angiotensin Androgens and estrogens Neurotransmitters that are also hormones Pepsin and ghrelin
B Hormones that are synthesized by non-vesicle-mediated pathways include the glucocorticoids, androgens, estrogens, and mineralocorticoids—all steroids derived from cholesterol.
Which structure controls the functions of the greatest number of target glands and cells? Thyroid gland Pituitary gland Adrenal cortex Pancreas
B The pituitary gland has been called the master gland because its hormones control the functions of many target glands and cells. It supersedes the importance of the thyroid, adrenal cortex, or pancreas in this regulatory role.
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 Hypothyroidism Calcium insufficiency Hypoglycemia
B 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 acts as a signal-relaying bridge between multiple body systems and the pituitary gland? Posterior pituitary Thyroid Hypothalamus Parathyroid
C 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 client experiences an increase in thyroid hormone as a result of a thyroid tumor. Which hormonal response demonstrates the negative feedback mechanism? decreased adrenocorticotropic hormone (ACTH) increased thyrotropin-releasing hormone (TRH) increased follicle-stimulating hormone (FSH) decreased thyroid-stimulating hormone (TSH)
D 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. When there is an excess of thyroid hormones present, there should be a reduction in TSH levels (i.e., there is no need to stimulate more thyroid hormone production when there is already an excess present). The other hormones listed do not have a negative feedback relationship with thyroid hormone production.
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? Action of releasing hormones from hypothalamus Steady-state continuous release Direct neural stimulation Homeostatic receptors on surface of gland
A 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.
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 diabetes. Client has hypothyroidism. Client has anuria. Client has anemia.
C 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.
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 releases neurotransmitters when the "flight or flight" mechanism is stimulated. The thyroid gland is responsible for regulating serum calcium levels. The thyroid gland is responsible for increasing the metabolic rate. The thyroid gland promotes development of secondary sex characteristics.
C 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.
Which physiologic process best exemplifies a positive feedback mechanism? regulation of blood glucose levels by insulin release of antidiuretic hormone when sodium levels are higher than normal release of parathyroid hormone in response to decreased serum calcium levels increase in prolactin secretion that occurs with more frequent breastfeeding
D 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. Correction of alterations in homeostasis is normally achieved using negative feedback mechanisms, such as those accomplished by insulin, parathyroid hormone, and antidiuretic hormone. In each of these cases, the stimulus results in an response that causes an opposite physiologic effect. For example, high blood glucose levels stimulate the release of insulin which then results in a lowering of the blood glucose level.
Cyclic adenosine monophosphate (cAMP) performs which role in the functioning of the endocrine system? Acting as a high-affinity receptor on the surface of target cells Inactivating hormones to prevent excess accumulation Mediating hormone synthesis by non-vesicle-mediated pathways Acting as a second messenger to mediate hormone action on target cells
D 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
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 Androstenedione, an adrenal androgen Dehydroepiandrosterone, an adrenal androgen Aldosterone, a mineralocorticoid
A 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.
A nurse examines the laboratory values of a client in heart failure. Which value indicates a compensatory hormone mechanism? Elevated atrial natriuretic hormone Decreased hematocrit Decreased red blood cell count Elevated serum pH
A 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.
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 Anterior pituitary Cerebral cortex Cerebellum
A 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.
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. releases hormones into the blood that is transported throughout the body. responds to neurotransmitter molecules within milliseconds. glands are widely scattered throughout the body.
ABC 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 physician suspects a client may be experiencing hypofunction of an endocrine organ. Select the most appropriate test to determine organ function. Imaging studies Suppression tests Stimulation tests Genetic testing
C 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 undergoing an evaluation of hormone levels asks, "What regulates the hormone levels?" Which response by the nurse would be considered most accurate? The positive feedback loop The hypophysial portal system The hypothalamic-pituitary-target cell system Exogenous forms of hormones
C 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.
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." "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."
D 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.
Paracrine action involves which characteristic? act on a distant target cell act on the same cells which secreted the hormone autoregulation act locally on cells other than those that produce the hormone
D When hormones act locally on cells other than those that produced the hormone, the action is called paracrine. Paracrine action is not synonymous with autoregulation, and action on the same cells that produced the hormone is autocrine action. Endocrine hormones affect distant cells via release into the blood stream.