NR 507 WEEK 2 QUIZ QUESTIONS AND ANSWERS

NR 507 WEEK 2 QUIZ QUESTIONS AND ANSWERS Water movement between the intracellular fluid compartment and the extracellular compartment is primarily a function of osmotic forces. The movement of water between ICF and ECF compartments is primarily a function of osmotic forces. (Osmosis and other mechanisms of passive transport are discussed in Chapter 1.) How does the loss of chloride during vomiting cause metabolic alkalosis Loss of chloride causes retention of bicarbonate to maintain the anion balance. When acid loss is caused by vomiting with depletion of ECF and chloride (hypochloremic metabolic alkalosis), renal compensation is not very effective because the volume depletion and loss of electrolytes (Na+, K+, H+, Cl-) stimulate a paradoxical response by the kidneys. The kidneys increase sodium and bicarbonate reabsorption with excretion of hydrogen. Bicarbonate is reabsorbed to maintain an anionic balance because the ECF chloride concentration is decreased. What is a major determinant of the resting membrane potential necessary for transmission of nerve impulses? The ratio between intracellular K+ and extracellular potassium The ratio of K+ in the ICF to K+ in the ECF is the major determinant of the resting membrane potential, which is necessary for the transmission and conduction of nerve impulses, maintenance of normal cardiac rhythms, and skeletal and smooth muscle contraction. Why are infants susceptible to significant losses in total body water (TBW)? Because an infant’s kidneys are not mature enough to counter fluids losses Infants are particularly susceptible to significant changes in TBW because of their high metabolic rate and the accelerated turnover of body fluids caused by their greater body surface area in proportion to total body size. Loss of fluids from diarrhea can represent a significant proportion of body weight. Renal mechanisms that regulate fluid and electrolyte conservation may not be mature enough to counter the losses, so dehydration may develop rapidly At the arterial end of capillaries, fluid moves from the intravascular space into the interstitial space because the capillary hydrostatic pressure is higher than the capillary oncotic pressure. At the arterial end of capillaries, fluid moves from the intravascular space into the interstitial, because capillary hydrostatic pressure is higher than the capillary oncotic pressure. When thirst is experienced, how are osmoreceptors activated? By an increase in the osmotic pressure of the plasma Thirst is experienced when water loss equals 2% of an individual’s body weight or when there is an increase in osmolality. Dry mouth, hyperosmolality, and plasma volume depletion activate osmoreceptors (neurons located in the hypothalamus that are stimulated by increased osmolality). Physiologic pH is maintained around 7.4 because bicarbonate (HCO3) and carbonic acid (H2CO3) exist in a ratio of 20:1. The relationship between bicarbonate and carbonic acid is usually expressed as a ratio. When the pH is 7.40, this ratio is 20:1 (bicarbonate/carbonic acid). Pulmonary edema usually begins at a pulmonary capillary wedge pressure or left atrial pressure of _____ mm Hg. 20 Pulmonary edema usually begins to develop at a pulmonary capillary wedge pressure or left atrial pressure of 20 mm Hg _____ is a fulminant form of respiratory failure characterized by acute lung inflammation and diffuse alveolocapillary injury. Acute respiratory distress syndrome (ARDS) ARDS is a fulminant form of respiratory failure characterized by acute lung inflammation and diffuse alveolocapillary injury. Dyspnea is not a result of decreased blood flow to the medulla oblongata. There are no data to support the role of decreased blood flow to the medulla oblongata as being a cause of dyspnea.