Why are infants most susceptible to significant losses in total body water?
High body surface-to-body size ratio
Slow metabolic rate
Kidneys are not mature enough to counter fluid losses
Inability to communicate adequately when he or she is thirsty
Why does obesity create a greater risk for dehydration in people?
Adipose cells contain little water because fat is water repelling.
The metabolic rate of obese adults is slower than the rate of lean adults.
The rate of urine output of obese adults is higher than in lean adults.
The thirst receptors of the hypothalamus do not function effectively.
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?
Respiratory alkalosis
Metabolic acidosis
Respiratory acidosis
Metabolic alkalosis
Water movement between the intracellular fluid (ICF) compartment and the extracellular fluid (ECF) compartment is primarily a function of what?
Osmotic forces
Plasma oncotic pressure
Antidiuretic hormone
Hydrostatic forces
In addition to osmosis, what force is involved in the movement of water between the plasma and interstitial fluid spaces?
Oncotic pressure
Buffering
Net filtration
Hydrostatic pressure
Venous obstruction is a cause of edema because of an increase in which pressure?
Capillary hydrostatic
Interstitial hydrostatic
Capillary oncotic
Interstitial oncotic
At the arterial end of capillaries, why does fluid move from the intravascular space into the interstitial space?
Interstitial hydrostatic pressure is higher than the capillary hydrostatic pressure.
Capillary hydrostatic pressure is higher than the capillary oncotic pressure.
Interstitial oncotic pressure is higher than the interstitial hydrostatic pressure.
Capillary oncotic pressure is lower than the interstitial hydrostatic pressure.
Low plasma albumin causes edema as a result of a reduction in which pressure?
Plasma oncotic
How are secretion of antidiuretic hormone (ADH) and the perception of thirst stimulated?
Decrease in serum sodium
Increase in plasma osmolality
Increase in glomerular filtration rate
Decrease in osmoreceptor stimulation
Thirst activates osmoreceptors following an increase in which blood plasma component?
Aldosterone
Osmotic pressure
A student asks about natriuretic peptides. Which statement by the professor is most accurate?
Decrease blood pressure and increase sodium and water excretion.
Increase blood pressure and decrease sodium and water excretion.
Increase heart rate and decrease potassium excretion.
Decrease heart rate and increase potassium excretion.
When changes in total body water are accompanied by proportional changes in electrolytes, what type of alteration occurs?
Isotonic
Hypertonic
Hypotonic
Normotonic
Which enzyme is secreted by the juxtaglomerular cells of the kidney when circulating blood volume is reduced?
Angiotensin I
Angiotensin II
Renin
A patient in the hospital has hypernatremia. What condition should the healthcare professional assess for?
Syndrome of inappropriate antidiuretic hormone
Hypersecretion of aldosterone
Brief bouts of vomiting or diarrhea
Excessive diuretic therapy
A patient has a serum sodium level of 165 mEq/L. The healthcare professional explains that the clinical manifestations of confusion, convulsions, cerebral hemorrhage, and coma are caused by what mechanism?
High sodium in the blood vessels pulls water out of the brain cells into the blood vessels, causing brain cells to shrink.
High sodium in the brain cells pulls water out of the blood vessels into the brain cells, causing them to swell.
Low sodium in the blood vessels pulls potassium out of the brain cells, which slows the synapses in the brain.
Low sodium in the blood vessels draws chloride into the brain cells followed by water, causing the brain cells to swell.
What does vomiting-induced metabolic alkalosis cause?
Retained sodium to bind with the chloride
Hydrogen to move into the cell and exchange with potassium
Retention of bicarbonate to maintain the anion balance
Hypoventilation to compensate for the metabolic alkalosis
The pathophysiologic process of edema is related to which mechanism?
Sodium depletion
Decreased capillary hydrostatic pressure
Increased plasma oncotic pressure
Lymphatic obstruction
Why is insulin used to treat hyperkalemia?
Stimulates sodium to be removed from the cell in exchange for potassium
Binds to potassium to remove it through the kidneys
Transports potassium from the blood into the cell along with glucose
Breaks down the chemical components of potassium, inactivating it
A major determinant of the resting membrane potential necessary for the transmission of nerve impulses is the ratio between what?
Intracellular and extracellular Na+
Intracellular and extracellular K+
Intracellular Na+ and extracellular K+
Intracellular K+ and extracellular Na+
During acidosis, the body compensates for the increase in serum hydrogen ions by shifting hydrogen ions into the cell in exchange for which electrolyte?
Oxygen
Sodium
Potassium
Magnesium
A healthcare professional is caring for four patients. Which patient should the professional assess for hyperkalemia?
Hyperparathyroidism
Vomiting
Renal failure
Hyperaldosteronism
In hyperkalemia, what change occurs to the cells’ resting membrane potential?
Hypopolarization
Hyperexcitability
Depolarization
Repolarization
A patient’s chart indicates Kussmaul respirations. The student asks the healthcare professional what this is caused by. What response by the professional is most accurate?
Anxiety leads to Kussmaul respirations and is a cause of respiratory acidosis.
A compensatory measure is needed to correct metabolic acidosis.
Diabetic ketoacidosis is leading to metabolic acidosis
More oxygen is necessary to compensate for respiratory acidosis.
A healthcare provider notes that tapping the patient’s facial nerve leads to lip twitching. What electrolyte value is correlated with this finding?
K+: 2.8 mEq/L
K+: 5.4 mEq/L
Ca++: 8.2 mg/dL
Ca++: 12.9 mg/dL
A patient has a history of excessive use of magnesium-containing antacids and aluminum-containing antacids. What lab value does the healthcare professional correlate to this behavior?
Magnesium 1.8 mg/dL
Phosphate 1.9 mg/dL
Sodium 149 mEq/L
Potassium 2.5 mEq/L
A healthcare professional is caring for four patients. Which patient should the professional assess for hypermagnesemia as a priority?
Hepatitis
Trauma to the hypothalamus
Pancreatitis
Physiologic pH is maintained at approximately 7.4 because bicarbonate (HCO3) and carbonic acid (H2CO3) exist in what ratio?
20:1
1:20
10:2
10:5
Where is two thirds of the body’s water found?
Interstitial fluid spaces
Vascular system
Intracellular fluid compartments
Intraocular fluids
A healthcare professional just administered a large dose of insulin to a patient. Which electrolyte value should the professional monitor as a priority?
Calcium
Why does increased capillary hydrostatic pressure result in edema?
Losses or diminished production of plasma albumin
Inflammation resulting from an immune response
Blockage within the lymphatic channel system
Sodium and water retention
A patient’s electrocardiogram (ECG) shows tall, peaked T waves. What lab value or assessment would the healthcare professional correlate with this finding?
Positive Chvostek sign
Serum potassium 6.7 mEq/L
Nausea and vomiting
Serum sodium 138 mEq/L
