GNRS 582 PATHO EXAM 2 QUESTIONS & ANSWERS
Explain the lining of nasopharynx and respiratory bronchi - Answers - The
Nasopharynx/oropharynx make up the upper airway. They are lined with a ciliated
mucosa that warms and humidifies inspired air and removes foreign particles from it.
Bronchial walls have three layers.
1) epithelial lining - contains goblet cells which secrete mucous and ciliated cells
(mucocilliary tract)
2) smooth muscle layer -
3) connective tissue layer -
Discuss the pathophysiology of newborns with respiratory distress - Answers -
Significant cause of neonatal morbidity and mortality, occurring mainly in premature
infants.
Caused by surfactant deficiency, which decreases the alveolar surface area available
for gas exchange.
Lack of surfactant causes alveoli to NOT inflate after exhalation.
Surfactant production in infants typically happens at 30 weeks of gestation.
Net effect is atelectasis resulting in significant hypoxemia.
Differentiate Perfusion and Diffusion - Answers - Perfusion: Distribution of gas in the
blood, ie O2 in blood. Pulse ox measures perfusion.
Diffusion: Gas exchange into the blood, ie O2 diffusing into blood
Explain the basement membrane, capillary lumen and macrophages - Answers -
Basement Membrane: Outermost border of alveolar wall. It is thin and is primarily
involved in gas exchange with the pulmonary capillaries.
Capillary Lumen: Blood flows through this. Gas exchange between Capillary and
basement membrane allow for diffusion of O2 into the blood and exhalation of CO2.
Macrophages: cells that ingest foreign material that reaches the alveolus and prepare it
for removal through the lymphatics.
Identify the pleural membranes - Answers - Pleural membranes line the thoracic cavity
enveloping the long, and then folding over on itself before adhering to the chest wall.
The membrane covering the lungs is called the VISCERAL PLEURA.
The PARIETAL PLEURA lines the thoracic cavity (attached to the chest wall).
The are between the two pleurae is called the PLEURAL SPACE or PLEURAL CAVITY.
Normally pleural fluid fills this space allowing the layers to slide over each other.
Pressure is usually subatmospheric (-4 to -10 mmHg)
Explain how the brain controls respirations - Answers - Respiration is controlled by the
respiratory center in the brain stem, transmitting impulses to the respiratory muscles,
causing them to contract and relax.
It is composed of: the Dorsal Respiratory Group, Ventral Respiratory Group,
Pneumotaxic center, and the apneustic center.
, Basic Automatic rhythm is set by DDRG which receives afferent input from peripheral
chemoreceptros.
VRG becomes active the increased effort is required.
Pneumotaxic and apneustic do not participate in normal breathing
Discuss Surfactant - Answers - Lipoprotein secreted by type II alveolar cells. They coat
the inner surface of alveolus and lowers alveolar surface tension at end-expiration,
thereby preventing lung collapse.
It is made of two groups of surfactant proteins:
1) one consists of small hydrophobic molecules that have a detergent-like effect that
separates the liquid molecules, decreasing alveolar surface tension.
2) The second group consists of large hydrophilic molecules called collectins that inhibit
foreign pathogens.
Discuss the transport of O2 and CO2 - Answers - 4 steps for O2 transport
1) Ventilation of the lungs, 2) diffusion of O2 from the alveoli into the capillary blood, 3)
perfusion of systemic capillaries with oxygenated blood, 4) diffusion of oxygen from
systemic capillaries into the cells.
Co2 transport occurs in reverse order:
1) diffusion of CO2 from cells into systemic capillaries, 2) perfusion of the pulmonary
capillary bed by venous blood, 3) diffusion of carbon dioxide into the alveoli, and 4)
removal of Co2 from the lung by ventilation.
If any step in gas transport is impaired by a respiratory or cardio disorder, gas exchange
at cellular level is compromised.
Explain the relationship of increased residual volume and lung compliance - Answers -
Compliance is defined as the measure of lung and chest wall distensibility. It represents
the relative ease with which these structures can be stretched and is the opposite of
elasticity.
Increased compliance indicates that the lungs or chest wall is abnormally easy to inflate
and has lost some recoil, resulting in increased residual volume.
Discuss orthopnea and PND - Answers - Orthopnea is dyspnea that occurs when an
individual lies flat and is common in individuals with heart failure. The Recumbent
position redistributes body water, causes the abdominal contents to exert pressure on
the diaphragm, and decrease the efficiency of the respiratory muscles.
Paroxysmal nocturnal dyspnea occurs in people with pulmonary of cardiac disease,
typically waking at night gasping for air and have to sit of stand to relieve the dyspnea.
Identify Cheyne-Stokes respirations - Answers - Characterized by alternating periods
of deep and shallow breathing. Apnea lasting from 15 to 60 seconds is followed by
ventilations that increase in volume until a peak is reached; then ventilation decreases
again to apnea.
Results from any condition that reduces blood flow to the brain stem. Neurologic
impairment above the brain stem is also a contributing factor.
Explain the lining of nasopharynx and respiratory bronchi - Answers - The
Nasopharynx/oropharynx make up the upper airway. They are lined with a ciliated
mucosa that warms and humidifies inspired air and removes foreign particles from it.
Bronchial walls have three layers.
1) epithelial lining - contains goblet cells which secrete mucous and ciliated cells
(mucocilliary tract)
2) smooth muscle layer -
3) connective tissue layer -
Discuss the pathophysiology of newborns with respiratory distress - Answers -
Significant cause of neonatal morbidity and mortality, occurring mainly in premature
infants.
Caused by surfactant deficiency, which decreases the alveolar surface area available
for gas exchange.
Lack of surfactant causes alveoli to NOT inflate after exhalation.
Surfactant production in infants typically happens at 30 weeks of gestation.
Net effect is atelectasis resulting in significant hypoxemia.
Differentiate Perfusion and Diffusion - Answers - Perfusion: Distribution of gas in the
blood, ie O2 in blood. Pulse ox measures perfusion.
Diffusion: Gas exchange into the blood, ie O2 diffusing into blood
Explain the basement membrane, capillary lumen and macrophages - Answers -
Basement Membrane: Outermost border of alveolar wall. It is thin and is primarily
involved in gas exchange with the pulmonary capillaries.
Capillary Lumen: Blood flows through this. Gas exchange between Capillary and
basement membrane allow for diffusion of O2 into the blood and exhalation of CO2.
Macrophages: cells that ingest foreign material that reaches the alveolus and prepare it
for removal through the lymphatics.
Identify the pleural membranes - Answers - Pleural membranes line the thoracic cavity
enveloping the long, and then folding over on itself before adhering to the chest wall.
The membrane covering the lungs is called the VISCERAL PLEURA.
The PARIETAL PLEURA lines the thoracic cavity (attached to the chest wall).
The are between the two pleurae is called the PLEURAL SPACE or PLEURAL CAVITY.
Normally pleural fluid fills this space allowing the layers to slide over each other.
Pressure is usually subatmospheric (-4 to -10 mmHg)
Explain how the brain controls respirations - Answers - Respiration is controlled by the
respiratory center in the brain stem, transmitting impulses to the respiratory muscles,
causing them to contract and relax.
It is composed of: the Dorsal Respiratory Group, Ventral Respiratory Group,
Pneumotaxic center, and the apneustic center.
, Basic Automatic rhythm is set by DDRG which receives afferent input from peripheral
chemoreceptros.
VRG becomes active the increased effort is required.
Pneumotaxic and apneustic do not participate in normal breathing
Discuss Surfactant - Answers - Lipoprotein secreted by type II alveolar cells. They coat
the inner surface of alveolus and lowers alveolar surface tension at end-expiration,
thereby preventing lung collapse.
It is made of two groups of surfactant proteins:
1) one consists of small hydrophobic molecules that have a detergent-like effect that
separates the liquid molecules, decreasing alveolar surface tension.
2) The second group consists of large hydrophilic molecules called collectins that inhibit
foreign pathogens.
Discuss the transport of O2 and CO2 - Answers - 4 steps for O2 transport
1) Ventilation of the lungs, 2) diffusion of O2 from the alveoli into the capillary blood, 3)
perfusion of systemic capillaries with oxygenated blood, 4) diffusion of oxygen from
systemic capillaries into the cells.
Co2 transport occurs in reverse order:
1) diffusion of CO2 from cells into systemic capillaries, 2) perfusion of the pulmonary
capillary bed by venous blood, 3) diffusion of carbon dioxide into the alveoli, and 4)
removal of Co2 from the lung by ventilation.
If any step in gas transport is impaired by a respiratory or cardio disorder, gas exchange
at cellular level is compromised.
Explain the relationship of increased residual volume and lung compliance - Answers -
Compliance is defined as the measure of lung and chest wall distensibility. It represents
the relative ease with which these structures can be stretched and is the opposite of
elasticity.
Increased compliance indicates that the lungs or chest wall is abnormally easy to inflate
and has lost some recoil, resulting in increased residual volume.
Discuss orthopnea and PND - Answers - Orthopnea is dyspnea that occurs when an
individual lies flat and is common in individuals with heart failure. The Recumbent
position redistributes body water, causes the abdominal contents to exert pressure on
the diaphragm, and decrease the efficiency of the respiratory muscles.
Paroxysmal nocturnal dyspnea occurs in people with pulmonary of cardiac disease,
typically waking at night gasping for air and have to sit of stand to relieve the dyspnea.
Identify Cheyne-Stokes respirations - Answers - Characterized by alternating periods
of deep and shallow breathing. Apnea lasting from 15 to 60 seconds is followed by
ventilations that increase in volume until a peak is reached; then ventilation decreases
again to apnea.
Results from any condition that reduces blood flow to the brain stem. Neurologic
impairment above the brain stem is also a contributing factor.
