NURS 6320 Final Exam (Ch 2, 3, 8, 9) | Answered with Rationales

NURS 6320 Final Exam (Ch 2, 3, 8, 9) | Answered with Rationales A patient's blood gases reveal the following findings: pH, 7.3; bicarbonate (HCO3) 27 mEq/L; carbon dioxide (CO2), 58 mm Hg. What is the interpretation of these gases? a. Respiratory alkalosis b. Metabolic acidosis c. Respiratory acidosis d. Metabolic alkalosis The values provided in this question characterize only acute uncompensated respiratory acidosis. What causes the clinical manifestations of confusion, convulsions, cerebral hemorrhage, and coma in hypernatremia? a. High sodium in the blood vessels pulls water out of the brain cells into the blood vessels, causing brain cells to shrink. b. High sodium in the brain cells pulls water out of the blood vessels into the brain cells, causing them to swell. c. High sodium in the blood vessels pulls potassium out of the brain cells, which slows the synapses in the brain. d. High sodium in the blood vessels draws chloride into the brain cells followed by water, causing the brain cells to swell Hypertonic (hyperosmolar) imbalances result in an extracellular fluid concentration greater than 0.9% salt solution (e.g., water loss or solute gain); cells shrink in a hypertonic fluid (see Table 3-7). This shrinking of cells results in the symptoms described in the question. The other options do not accurately describe the cause of these symptoms as they relate to hypernatremia Vomiting-induced metabolic alkalosis, resulting in the loss of chloride, causes: a. Retained sodium to bind with the chloride b. Hydrogen to move into the cell and exchange with potassium to maintain cation balance c. Retention of bicarbonate to maintain the anion balance d. Hypoventilation to compensate for the metabolic alkalosis When vomiting with the depletion of ECF and chloride (hypochloremic metabolic alkalosis) causes acid loss, renal compensation is not effective; the volume depletion and loss of electrolytes (sodium [Na+], potassium [K+], hydrogen [H+], chlorine [Cl-]) stimulate a paradoxic response by the kidneys. The kidneys increase sodium and bicarbonate reabsorption with the excretion of hydrogen. Bicarbonate is reabsorbed to maintain an anionic balance because the ECF chloride concentration is decreased. The other options do not accurately describe the mechanism that results from vomiting-induced metabolic alkalosis. Insulin is used to treat hyperkalemia because it: a. Stimulates sodium to be removed from the cell in exchange for potassium. b. Binds to potassium to remove it through the kidneys. c. Transports potassium from the blood to the cell along with glucose. d. Breaks down the chemical components of potassium, causing it to be no longer effective. Insulin contributes to the regulation of plasma potassium levels by stimulating the Na+, potassium-adenosine triphosphatase (K+-ATPase) pump, thereby promoting the movement of potassium simultaneously into the liver and muscle cells with glucose transport after eating. The intracellular movement of potassium prevents an acute hyperkalemia related to food intake. The other options do not accurately describe how insulin is used to treat hyperkalemia During acidosis, the body compensates for the increase in serum hydrogen ions by shifting hydrogen ions into the cell in exchange for which electrolyte? a. Oxygen b. Sodium c. Potassium d. Magnesium In states of acidosis, hydrogen ions shift into the cells in exchange for intracellular fluid potassium; hyperkalemia and acidosis therefore often occur together. This is not true of the other options. Causes of hyperkalemia include: a. Hyperparathyroidism and malnutrition b. Vomiting and diarrhea c. Renal failure and Addison disease d. Hyperaldosteronism and Cushing disease Hyperkalemia should be investigated when a history of renal disease, massive trauma, insulin deficiency, Addison disease, use of potassium salt substitutes, or metabolic acidosis exists. The other options are not known to be causes of hyperkalemia In hyperkalemia, what change occurs to the cells' resting membrane potential? a. Hypopolarization b. Hyperexcitability c. Depolarization d. Repolarization If extracellular potassium concentration increases without a significant change in intracellular potassium, then the resting membrane potential becomes more positive (i.e., changes from -90 to -80 mV) and the cell membrane is hypopolarized (i.e., the inside of the cell becomes less negative or partially depolarized [increase excitability]). The calcium and phosphate balance is influenced by which three substances? a. Parathyroid hormone, vasopressin, and vitamin D b. Parathyroid hormone, calcitonin, and vitamin D c. Thyroid hormone, vasopressin, and vitamin A d. Thyroid hormone, calcitonin, and vitamin A Three hormones regulate calcium and phosphate balance: parathyroid hormone (PTH), vitamin D, and calcitonin. Vasopressin, thyroid hormone, and vitamin A do not influence calcium and phosphate balance It is true that Kussmaul respirations indicate: a. Anxiety is a cause of respiratory acidosis. b. A compensatory measure is needed to correct metabolic acidosis. c. Diabetic ketoacidosis is the cause of the metabolic acidosis. d. More oxygen is necessary to compensate for respiratory acidosis Deep, rapid respirations (Kussmaul respirations) are indicative of respiratory compensation for metabolic acidosis. The other options are not true. Chvostek and Trousseau signs indicate which electrolyte imbalance? a. Hypokalemia b. Hyperkalemia c. Hypocalcemia d. Hypercalcemia Two clinical signs of hypocalcemia are the Chvostek sign and Trousseau sign. These clinical signs are not indicative of any of the other options. An excessive use of magnesium-containing antacids and aluminum-containing antacids can result in: a. Hypomagnesemia b. Hypophosphatemia c. Hyponatremia d. Hypokalemia The most common causes of hypophosphatemia are intestinal malabsorption and increased renal excretion of phosphate. Inadequate absorption is associated with vitamin D deficiency, the use of magnesium and aluminum-containing antacids (which bind with phosphorus), long-term alcohol abuse, and malabsorption syndromes. The excessive use of such antacids will not result in the other options. The most common cause of hypermagnesemia is: a. Hepatitis b. Renal failure c. Trauma to the hypothalamus d. Pancreatitis Renal failure usually causes hypermagnesemia, in which magnesium concentration is greater than 2.5 mEq/L. Hypermagnesemia is not a result of the other options Physiologic pH is maintained at approximately 7.4 because bicarbonate (HCO3) and carbonic acid (H2CO3) exist in a ratio of: a. 20:1 b. 1:20 c. 10:2 d. 10:5 The relationship between HCO3 and H2CO3 is usually expressed as a ratio. When the pH is 7.4, this ratio is 20:1 (HCO3:H2CO3). The other options do not accurately identify physiologic pH by the correct ratio of HCO3 and H2CO3 Which arterial pH will initiate the formation of ammonium (NH4) from ammonia (NH3), referred to as academia, in the tubular lumen of the kidney? a. 7.25 b. 7.35 c. 7.55 d. 7.65 Pathophysiologic changes in the concentration of hydrogen ion or base in the blood lead to acid-base imbalances. Acidemia is a state in which the pH of arterial blood is less than 7.35. NH3 is produced from glutamine in the epithelial cell and diffuses to the tubular lumen, where it combines with H+ to form NH4 It is true that when insulin is administered: a. The Na+, K+-ATPase pump is turned off. b. Potassium is moved out of muscle cells. c. The liver increases its potassium levels. d. Glucose transport is impaired. Insulin contributes to the regulation of plasma potassium levels by stimulating the Na+, K+-ATPase pump, thereby promoting the movement of potassium simultaneously into the liver and muscle cells with glucose transport after eating. The other options do not accurately describe the effect of insulin administration. The existence of hyperkalemia is likely to result in which changes to a person's electrocardiogram (ECG)? a. Flattened U waves b. Peaked T waves c. Depressed ST segments d. Peaked P waves Observed ECG changes include peaked T waves, prolonged PR interval, and absent P wave with a widened QRS complex. The other options are not related to hyperkalemia. Dehydration can cause which result? (Select all that apply.) a. Moist mucous membranes b. Weak pulses c. Tachycardia d. Polyuria e. Weight loss Significant water deficit is demonstrated by symptoms of dehydration that include headache, thirst, dry skin and mucous membranes, elevated temperature, weight loss, and decreased or concentrated urine (with the exception of diabetes insipidus). Skin turgor may be normal or decreased. Symptoms of hypovolemia include tachycardia, weak pulses, and postural hypotension Causes of hypocalcemia include: (Select all that apply.) a. Repeated blood administration b. Pancreatitis c. Decreased reabsorption of calcium d. Hyperparathyroidism e. Kidney stones Blood transfusions are a common cause of hypocalcemia because the citrate solution used in storing whole blood binds with calcium. Pancreatitis causes a release of lipases into soft-tissue spaces; consequently, the free fatty acids that are formed bind calcium, causing a decrease in ionized calcium. The other options are not recognized causes of hypocalcemia. The electrolyte imbalance called hyponatremia exhibits which clinical manifestations? (Select all that apply.) a. Headache b. Seizures c. Paranoia d. Confusion e. Lethargy Behavioral and neurologic changes characteristic of hyponatremia include lethargy, headache, confusion, apprehension, seizures, and coma. Paranoia is not associated with hyponatremia. The electrolyte imbalance hypercalcemia exhibits which clinical manifestations? (Select all that apply.) a. Diarrhea b. Calcium based kidney stones c. ECG showing narrow T waves d. Lethargy e. Bradycardia Fatigue, weakness, lethargy, anorexia, nausea, and constipation are common. Behavioral changes may occur. Impaired renal function frequently develops, and kidney stones form as precipitates of calcium salts. A shortened QT segment and depressed widened T waves also may be observed on the ECG, with bradycardia and varying degrees of heart block The electrolyte imbalance hypokalemia exhibits which clinical manifestations? (Select all that apply.) a. Paralytic ileus b. Sinus bradycardia c. Atrioventricular block d. Dry mucous membranes e. Tetany A variety of dysrhythmias may occur, including sinus bradycardia, atrioventricular block, paroxysmal atrial tachycardia, and paralytic ileus. The other options are not related to hypokalemia. An imbalance of potassium can produce which dysfunctions? (Select all that apply.) a. Weakness skeletal muscles b. Cardiac dysrhythmias c. Smooth muscle atony d. Visual impairment e. Hearing loss Symptoms of hyperkalemia vary, but common characteristics are muscle weakness or paralysis and dysrhythmias with changes in the ECG. A wide range of metabolic dysfunctions may result from hypokalemia. Neuromuscular excitability is decreased, causing skeletal muscle weakness, smooth muscle atony, and cardiac dysrhythmias Which type of cell adaptation occurs when normal columnar ciliated epithelial cells of the bronchial lining have been replaced by stratified squamous epithelial cells? a. Hyperplasia b. Metaplasia c. Dysplasia d. Anaplasia Metaplasia is the reversible replacement of one mature cell by another, sometimes a less differentiated cell type. The best example of metaplasia is the replacement of normal columnar ciliated epithelial cells of the bronchial (airway) lining by stratified squamous epithelial cells. The other options do not accurately describe the event in the question. The mammary glands enlarge during pregnancy primarily as a consequence of hormonal: a. Atrophy b. Hyperplasia c. Anaplasia d. Dysplasia Hormonal hyperplasia occurs chiefly in estrogen-dependent organs, such as the uterus and breast. The remaining options do not adequately describe the consequence of hormones on breast tissue during pregnancy Which statement is a description of the characteristics of apoptosis? a. Programmed cell death of scattered, single cells b. Characterized by swelling of the nucleus and cytoplasm c. Unpredictable patterns of cell death d. Results in benign malignancies Apoptosis is an active process of cellular self-destruction, also known as programmed cell death, which is implicated in normal and pathologic tissue changes. The remaining options do not accurately describe the characteristics of apoptosis During cell injury caused by hypoxia, an increase in the osmotic pressure occurs within the cell because: a. Plasma proteins enter the cell. b. The adenosine triphosphatase (ATPase)-driven pump is stronger during hypoxia. c. Sodium chloride enters the cell. d. An influx of glucose occurs through the injured cell membranes. In hypoxic injury, movement of fluid and ions into the cell is associated with acute failure of metabolism and a loss of ATP production. Normally, the pump that transports sodium ions out of the cell is maintained by the presence of ATP and ATPase, the active-transport enzyme. In metabolic failure caused by hypoxia, reduced ATP and ATPase levels permit sodium to accumulate in the cell, whereas potassium diffuses outward. The increase of intracellular sodium increases osmotic pressure, which draws more water into the cell. (Transport mechanisms are described in Chapter 1.) The remaining options do not accurately describe the cell injury that results in increased osmotic pressure caused by hypoxia. In hypoxic injury, sodium enters the cell and causes swelling because: a. The cell membrane permeability increases for sodium during periods of hypoxia. b. ATP is insufficient to maintain the pump that keeps sodium out of the cell. c. The lactic acid produced by the hypoxia binds with sodium in the cell. d. Sodium cannot be transported to the cell membrane during hypoxia. In hypoxic injury, movement of fluid and ions into the cell is associated with acute failure of metabolism and a loss of ATP production. Normally, the presence of ATP and ATPase, the active-transport enzyme, maintains the pump that transports sodium ions out of the cell. In metabolic failure caused by hypoxia, reduced ATP and ATPase levels permit sodium to accumulate in the cell, whereas potassium diffuses outward. The other options do not accurately describe the cause of the swelling caused by hypoxia. What type of necrosis results from ischemia of neurons and glial cells? a. Coagulative b. Liquefactive c. Caseous d. Gangrene Liquefactive necrosis commonly results from ischemic injury to neurons and glial cells in the brain. The other types of necrosis are not related to ischemic injuries in the brain. What type of necrosis is often associated with pulmonary tuberculosis? a. Bacteriologic b. Caseous c. Liquefactive d. Gangrenous Caseous necrosis, which commonly results from tuberculous pulmonary infection, particularly Mycobacterium tuberculosis, is a combination of coagulative and liquefactive necrosis. The other types of necrosis are not observed in pulmonary tuberculosis What type of necrosis is associated with wet gangrene? a. Coagulative b. Liquefactive c. Caseous d. Gangrene Wet gangrene develops only when neutrophils invade the site, causing liquefactive necrosis. After ovulation, the uterine endometrial cells divide under the influence of estrogen. This process is an example of hormonal: a. Hyperplasia b. Dysplasia c. Hypertrophy d. Anaplasia Hormonal hyperplasia chiefly occurs in estrogen-dependent organs, such as the uterus and breast. After ovulation, for example, estrogen stimulates the endometrium to grow and thicken for reception of the fertilized ovum. The other options do not accurately describe the process identified in the question The abnormal proliferation of cells in response to excessive hormonal stimulation is called: a. Dysplasia b. Pathologic dysplasia c. Hyperplasia d. Pathologic hyperplasia Pathologic hyperplasia is the abnormal proliferation of normal cells and can occur as a response to excessive hormonal stimulation or the effects of growth factors on target cells (see Figure 2-4). The other options do not accurately identify the term for the results of excessive hormonal stimulation on cells. Removal of part of the liver leads to the remaining liver cells undergoing compensatory: a. Atrophy b. Metaplasia c. Hyperplasia d. Dysplasia Compensatory hyperplasia is an adaptive mechanism that enables certain organs to regenerate. For example, the removal of part of the liver leads to hyperplasia of the remaining liver cells (hepatocytes) to compensate for the loss. The other options do not accurately identify the compensatory process described in the question. What is the single most common cause of cellular injury? a. Hypoxic injury b. Chemical injury c. Infectious injury d. Genetic injury Hypoxia, or lack of sufficient oxygen, is the single most common cause of cellular injury (see Figure 2-8). The other options are not a commonly observed as is the correct option During cell injury caused by hypoxia, sodium and water move into the cell because: a. Potassium moves out of the cell, and potassium and sodium are inversely related. b. The pump that transports sodium out of the cell cannot function because of a decrease in ATP levels. c. The osmotic pressure is increased, which pulls additional sodium across the cell membrane. d. Oxygen is not available to bind with sodium to maintain it outside of the cell. A reduction in ATP levels causes the plasma membrane's sodium-potassium (Na+-K+) pump and sodium-calcium exchange to fail, which leads to an intracellular accumulation of sodium and calcium and diffusion of potassium out of the cell. (The Na+-K+ pump is discussed in Chapter 1.) What is an example of compensatory hyperplasia? a. Hepatic cells increase cell division after part of the liver is excised. b. Skeletal muscle cells atrophy as a result of paralysis. c. The heart muscle enlarges as a result of hypertension. d. The size of the uterus increases during pregnancy. Compensatory hyperplasia is an adaptive mechanism that enables certain organs to regenerate. For example, the removal of part of the liver leads to hyperplasia of the remaining liver cells (hepatocytes) to compensate for the loss. The other options do not accurately describe the term compensatory hyperplasia. It is true that nondividing cells are: a. Found in gastrointestinal lining b. Affected by hyperplasia c. Incapable of synthesizing DNA d. Affected by only hypertrophy Gastrointestinal lining is made up of rapidly dividing cells. Hyperplasia and hypertrophy take place if the cells are capable of synthesizing DNA; however, only hypertrophy occurs in nondividing cells. Dysplasia refers to a(n): a. Abnormal increase in the number of a specific cell type b. True adaptive process at the cellular level c. Modification in the shape of a specific cell type