NUR 242 MED SURG EXAM 3 2025 TESTBANK. RECENTLY UPDATED ACTUAL EXAM WITH CORRECT SOLUTIONS. VERIFIED A+ PACK

NUR 242 MED SURG EXAM 3 2025 TESTBANK. RECENTLY UPDATED ACTUAL EXAM WITH CORRECT SOLUTIONS. VERIFIED A+ PACK What is ventilation? - CORRECT ANSthe movement of air into and out of the lungs What is perfusion? - CORRECT ANSthe circulation of blood through the lungs What are central chemoreceptors responsive to? - CORRECT ANSincreased H+ in the brain ECF; increased PaCO2; "hypercarbic drive" What are peripheral chemoreceptors responsive to? - CORRECT ANSdecreased pH; increased PaCO2; decreased PaO2; "hypoxic drive" 2 | P a g e What are elastic forces? - CORRECT ANSlungs recoil due to elastin, collagen, fibrin What are surface forces? - CORRECT ANSsurface tension due to water-air interface What is airway resistance? - CORRECT ANSopposition to flow caused by the forces of friction; primarily determined by airway radius What is the distensibility of the lungs? - CORRECT ANSease with which the lungs can be inflated What is lung distensibility increased in? - CORRECT ANSneonates and children; emphysema What is lung distensibility decreased in? - CORRECT ANSelderly; pneumonia, pulmonary edema, ARDS, atelectasis, fibrosis 3 | P a g e What is surfactant? - CORRECT ANScomplex substance lining the alveoli and smallest bronchioles containing phospholipids and a number of apoproteins which reduces surface tension throughout the lungs, thereby contributing to its general compliance; stabilizes the alveoli and keeps them dry What produces surfactant? - CORRECT ANSproduced by the Type II alveolar cells What is Ohm's law? - CORRECT ANSvelocity = driving force/resistance What is Poiseuille law? - CORRECT ANSresistance = (8 x viscosity x length) / (pi x radius^4) What happens if the radius in the lungs goes down? - CORRECT ANSthe resistance goes up How is the ventilation distributed in the lungs? - CORRECT ANSthe top of the lungs are more distended and less compliant whereas the lower lung is small and highly compliant 4 | P a g e What factors affect lung perfusion? - CORRECT ANSlung capacitance; low resistance system; flow influenced by gravity; resistance primarily determined by vessel radius What does hypoxia lead to? - CORRECT ANSvasoconstriction of pulmonary vessels What does prolonged hypoxia lead to? - CORRECT ANSpulmonary hypertension What factors affect alveolar-capillary diffusion? - CORRECT ANScapillary permeability; surface area available for diffusion; concentration gradient for the gas; distance for diffusion What causes right shifts (decreased affinity) in Hemoglobin-O2 affinity? - CORRECT ANSacidemia; hyperthermia; 5 | P a g e hypercarbia What causes left shifts (increased affinity) in Hemoglobin-O2 affinity? - CORRECT ANSalkalemia; hypothermia; hypocarbia What is hypoxemia? - CORRECT ANSdeficient blood oxygen; low PaO2; low O2 saturation What is hypoxia? - CORRECT ANSdecreased tissue oxygen What is hypoxic hypoxia? - CORRECT ANSdecreased tissue oxygen caused by decreased respirations What is anemic hypoxia? - CORRECT ANSdecreased tissue oxygen caused by decreased hemoglobin 6 | P a g e What is circulatory hypoxia? - CORRECT ANSdecreased tissue oxygen caused by decreased blood flow What is histotoxic hypoxia? - CORRECT ANSdecreased tissue oxygen caused by increased toxic substance What is ischemia? - CORRECT ANSgreatly reduced or interrupted flow through the arterial system, producing significant tissue hypoxia What is hypercapnia? - CORRECT ANSincreased level of CO2 in the blood What are S&S of acute hypoxia? - CORRECT ANSdyspnea; restlessness; palpitations; agitation; headache; tremors; diaphoresis; respiratory distress; cyanosis; tachypnea; tachycardia; dysrhythmias; hypertension; lethargy; confusion to coma