NUR 242 Med Surg Exam 3 Question and
Answer (2026) | Newest Update Verified
Answers with Detailed Rationales | A+
Verified
What are central chemoreceptors responsive to? -✓✓increased H+ in the brain ECF;
increased PaCO2;
"hypercarbic drive"
What are peripheral chemoreceptors responsive to? -✓✓decreased pH;
increased PaCO2;
decreased PaO2;
"hypoxic drive"
What are elastic forces? -✓✓lungs recoil due to elastin, collagen, fibrin
What are surface forces? -✓✓surface tension due to water-air interface
What is airway resistance? -✓✓opposition to flow caused by the forces of friction;
primarily determined by airway radius
What is the distensibility of the lungs? -✓✓ease with which the lungs can be inflated
What is lung distensibility increased in? -✓✓neonates and children;
emphysema
What is lung distensibility decreased in? -✓✓elderly;
pneumonia, pulmonary edema, ARDS, atelectasis, fibrosis
What is surfactant? -✓✓complex 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? -✓✓produced by the Type II alveolar cells
What is Ohm's law? -✓✓velocity = driving force/resistance
What is Poiseuille law? -✓✓resistance = (8 x viscosity x length) / (pi x radius^4)
What happens if the radius in the lungs goes down? -✓✓the resistance goes up
,How is the ventilation distributed in the lungs? -✓✓the top of the lungs are more
distended and less compliant whereas the lower lung is small and highly compliant
What factors affect lung perfusion? -✓✓lung capacitance;
low resistance system;
flow influenced by gravity;
resistance primarily determined by vessel radius
What does hypoxia lead to? -✓✓vasoconstriction of pulmonary vessels
What does prolonged hypoxia lead to? -✓✓pulmonary hypertension
What factors affect alveolar-capillary diffusion? -✓✓capillary permeability;
surface area available for diffusion;
concentration gradient for the gas;
distance for diffusion
What causes right shifts (decreased affinity) in Hemoglobin-O2 affinity? -✓✓acidemia;
hyperthermia;
hypercarbia
What causes left shifts (increased affinity) in Hemoglobin-O2 affinity? -✓✓alkalemia;
hypothermia;
hypocarbia
What is hypoxemia? -✓✓deficient blood oxygen;
low PaO2;
low O2 saturation
What is hypoxia? -✓✓decreased tissue oxygen
What is hypoxic hypoxia? -✓✓decreased tissue oxygen caused by decreased
respirations
What is anemic hypoxia? -✓✓decreased tissue oxygen caused by decreased
hemoglobin
What is circulatory hypoxia? -✓✓decreased tissue oxygen caused by decreased blood
flow
What is histotoxic hypoxia? -✓✓decreased tissue oxygen caused by increased toxic
substance
, What is ischemia? -✓✓greatly reduced or interrupted flow through the arterial system,
producing significant tissue hypoxia
What is hypercapnia? -✓✓increased level of CO2 in the blood
What are S&S of acute hypoxia? -✓✓dyspnea; restlessness; palpitations; agitation;
headache; tremors; diaphoresis; respiratory distress; cyanosis; tachypnea; tachycardia;
dysrhythmias; hypertension; lethargy; confusion to coma
What are some effects of hypercapnia? -✓✓respiratory acidosis (decreased pH from
increase in CO2); lethargy and confusion; increased HR and BP; flushed skin;
arrhythmias; seizures; coma; death
What is dyspnea? -✓✓subjective feeling of being SOB
What does dyspnea lead to? -✓✓decreased sense of wellness which may cause
psychological and social consequences
What is the leading cause of cancer death? -✓✓lung cancer
What is lung cancer most likely caused by? -✓✓cigarette smoking;
asbestos;
familial predisposition
What are the manifestations of lung cancer? -✓✓cough, hemoptysis (blood in cough
sputum);
hoarseness;
chest pain;
often disseminated (spread widely) at time of diagnosis
What are the types of bronchogenic carcinomas? -✓✓squamous cell lung carcinoma
(25-40%);
adenocarcinoma (20-40%);
small cell carcinoma (20-25%);
large cell carcinoma (10-15%)
What is acute airway obstruction caused by? -✓✓foreign body aspiration;
laryngospasm (spontaneous spasm of the vocal cords);
trauma
What is complete acute airway obstruction? -✓✓inspiratory chest movements but no air
movement;
tachycardia, cyanosis, rapid progression to unconsciousness
Answer (2026) | Newest Update Verified
Answers with Detailed Rationales | A+
Verified
What are central chemoreceptors responsive to? -✓✓increased H+ in the brain ECF;
increased PaCO2;
"hypercarbic drive"
What are peripheral chemoreceptors responsive to? -✓✓decreased pH;
increased PaCO2;
decreased PaO2;
"hypoxic drive"
What are elastic forces? -✓✓lungs recoil due to elastin, collagen, fibrin
What are surface forces? -✓✓surface tension due to water-air interface
What is airway resistance? -✓✓opposition to flow caused by the forces of friction;
primarily determined by airway radius
What is the distensibility of the lungs? -✓✓ease with which the lungs can be inflated
What is lung distensibility increased in? -✓✓neonates and children;
emphysema
What is lung distensibility decreased in? -✓✓elderly;
pneumonia, pulmonary edema, ARDS, atelectasis, fibrosis
What is surfactant? -✓✓complex 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? -✓✓produced by the Type II alveolar cells
What is Ohm's law? -✓✓velocity = driving force/resistance
What is Poiseuille law? -✓✓resistance = (8 x viscosity x length) / (pi x radius^4)
What happens if the radius in the lungs goes down? -✓✓the resistance goes up
,How is the ventilation distributed in the lungs? -✓✓the top of the lungs are more
distended and less compliant whereas the lower lung is small and highly compliant
What factors affect lung perfusion? -✓✓lung capacitance;
low resistance system;
flow influenced by gravity;
resistance primarily determined by vessel radius
What does hypoxia lead to? -✓✓vasoconstriction of pulmonary vessels
What does prolonged hypoxia lead to? -✓✓pulmonary hypertension
What factors affect alveolar-capillary diffusion? -✓✓capillary permeability;
surface area available for diffusion;
concentration gradient for the gas;
distance for diffusion
What causes right shifts (decreased affinity) in Hemoglobin-O2 affinity? -✓✓acidemia;
hyperthermia;
hypercarbia
What causes left shifts (increased affinity) in Hemoglobin-O2 affinity? -✓✓alkalemia;
hypothermia;
hypocarbia
What is hypoxemia? -✓✓deficient blood oxygen;
low PaO2;
low O2 saturation
What is hypoxia? -✓✓decreased tissue oxygen
What is hypoxic hypoxia? -✓✓decreased tissue oxygen caused by decreased
respirations
What is anemic hypoxia? -✓✓decreased tissue oxygen caused by decreased
hemoglobin
What is circulatory hypoxia? -✓✓decreased tissue oxygen caused by decreased blood
flow
What is histotoxic hypoxia? -✓✓decreased tissue oxygen caused by increased toxic
substance
, What is ischemia? -✓✓greatly reduced or interrupted flow through the arterial system,
producing significant tissue hypoxia
What is hypercapnia? -✓✓increased level of CO2 in the blood
What are S&S of acute hypoxia? -✓✓dyspnea; restlessness; palpitations; agitation;
headache; tremors; diaphoresis; respiratory distress; cyanosis; tachypnea; tachycardia;
dysrhythmias; hypertension; lethargy; confusion to coma
What are some effects of hypercapnia? -✓✓respiratory acidosis (decreased pH from
increase in CO2); lethargy and confusion; increased HR and BP; flushed skin;
arrhythmias; seizures; coma; death
What is dyspnea? -✓✓subjective feeling of being SOB
What does dyspnea lead to? -✓✓decreased sense of wellness which may cause
psychological and social consequences
What is the leading cause of cancer death? -✓✓lung cancer
What is lung cancer most likely caused by? -✓✓cigarette smoking;
asbestos;
familial predisposition
What are the manifestations of lung cancer? -✓✓cough, hemoptysis (blood in cough
sputum);
hoarseness;
chest pain;
often disseminated (spread widely) at time of diagnosis
What are the types of bronchogenic carcinomas? -✓✓squamous cell lung carcinoma
(25-40%);
adenocarcinoma (20-40%);
small cell carcinoma (20-25%);
large cell carcinoma (10-15%)
What is acute airway obstruction caused by? -✓✓foreign body aspiration;
laryngospasm (spontaneous spasm of the vocal cords);
trauma
What is complete acute airway obstruction? -✓✓inspiratory chest movements but no air
movement;
tachycardia, cyanosis, rapid progression to unconsciousness
