96 Questions
What is the primary function of cells in the conducting zone?
To remove inhaled pathogens
What is the type of epithelial cells found in the alveoli?
Squamous
What determines the flow of air in the respiratory tract?
Pressure gradient
What is the relationship between pressure and volume in the lungs?
Inversely proportional
What is the function of Type II alveolar cells?
Surfactant production
What is the direction of gas movement in the lungs?
From areas of higher pressure to areas of lower pressure
What percentage of airway resistance is attributed to the trachea and bronchi?
90%
What determines the ease of expanding the lungs?
Lung compliance (CL)
What is the effect of bronchoconstriction on gas exchange?
It decreases gas exchange
What is the primary determinant of airway resistance?
Radius of the airways
What is the equation that relates airflow to pressure?
F = (Palv - Patm)/R
What is the normal ratio of FEV1 to FVC?
80%
What is the formula for calculating total pulmonary ventilation?
Ventilation rate (breaths/min) x tidal volume (ml/breath)
What reduces the work of breathing?
Surfactant
What is the purpose of alveolar ventilation as a measure of ventilation efficiency?
To measure the volume of air that reaches the alveoli
What is the change in lung volume produced by a given change in the transpulmonary pressure?
ΔVL
What is the effect of hyperventilation on alveolar PO2 and PCO2?
Alveolar PO2 increases and PCO2 decreases
What occurs at the air-fluid interface in the alveoli?
Surface tension
What is the primary reason why only a portion of the air inhaled reaches the alveoli?
Anatomical dead space reduces alveolar ventilation
What is the purpose of measuring FEV1 in pulmonary function tests?
To diagnose chronic obstructive pulmonary disease
Which of the following is a factor that increases airway resistance?
Narrowing of airways
What is the formula for calculating alveolar ventilation?
Tidal volume - dead space volume
What is the effect of hyperventilation on alveolar PO2 and PCO2?
Alveolar PO2 increases, alveolar PCO2 decreases
What is the normal ratio of FEV1 to FVC?
80% or more
What is the primary factor that influences the magnitude of the change in lung volume produced by a given change in the transpulmonary pressure?
The lung compliance
Which of the following is a direct result of decreased lung compliance?
Increased work of breathing
What is the relationship between the radius of the airways and airway resistance, according to Poiseuille's law?
Airway resistance is inversely proportional to the fourth power of the radius of the airways
What is the effect of surfactant on the surface tension of the fluid lining the alveoli?
It decreases the surface tension
What is the primary determinant of the change in lung volume during normal inspiration at rest?
The difference between alveolar pressure and atmospheric pressure
What is the relationship between lung volumes and capacities during normal ventilation?
Lung volumes and capacities change during normal ventilation
What is the primary purpose of calculating anatomical dead space?
To calculate the volume of air that participates in gas exchange
Which of the following is a characteristic of restrictive lung diseases as measured by pulmonary function tests?
Decreased FEV1 and FVC
What is the effect of decreased airway radius on airway resistance?
It increases airway resistance
What is the formula for calculating alveolar ventilation?
Respiratory rate × (tidal volume - anatomical dead space)
What is the primary determinant of lung volumes and capacities?
Lung compliance
What is the effect of bronchodilation on airway resistance?
It decreases airway resistance
What is the primary function of the defence mechanisms in the respiratory tract?
To trap, remove or destroy potentially harmful substances
What happens to the diameter and surface area of the airways as they branch?
Diameter decreases and surface area increases
What is the function of vocalisation in the respiratory tract?
To create vibrations for speech or singing
What is the name given to the portion of the respiratory tract that is enclosed in the thorax?
Thoracic portion
What is the purpose of heating the air in the respiratory tract?
To avoid damaging the alveoli with cold air
How many integrated processes does external respiration involve?
4
What is the primary mechanism by which gases move in the lungs?
Diffusion down partial pressure gradients
What is the relationship between air flow and pressure in the respiratory tract?
Air flow is directly proportional to pressure
What determines the rate of air flow in the respiratory tract?
Pressure gradient and resistance
What is the primary function of the extensive network of capillaries in the lungs?
To facilitate gas exchange
What is the purpose of the cells in the conducting zone?
To trap and remove inhaled pathogens
What is the relationship between pressure and volume in the lungs, as described by Boyle's law?
Pressure is inversely proportional to volume
What is the primary function of the respiratory system that involves the regulation of pH?
Homeostatic regulation of pH
What is the term for the volume of air that reaches the alveoli after inhalation?
Alveolar ventilation
What is the factor that determines the magnitude of the change in lung volume produced by a given change in transpulmonary pressure?
Compliance
What is the term for the measurement of the volume of air that can be exhaled from the lungs after maximum inspiration?
Vital capacity
What is the effect of bronchoconstriction on airway resistance?
Increases airway resistance
What is the purpose of surfactant in the lungs?
To decrease surface tension in the alveoli
What is the relationship between the transpulmonary pressure and the change in lung volume?
The transpulmonary pressure is directly proportional to the change in lung volume
What is the primary factor that influences the magnitude of the change in lung volume produced by a given change in the transpulmonary pressure?
The lung compliance
What is the effect of surfactant on the work of breathing?
It decreases the work of breathing
What is the relationship between the length of the airways and airway resistance, according to Poiseuille's law?
The length of the airways is directly proportional to airway resistance
What is the primary determinant of lung volumes and capacities during normal ventilation?
The lung compliance
What is the equation that relates airflow to pressure in the lungs?
F = (Palv - Patm)/R
What is the primary reason why only 4.2 L of fresh air reaches the alveoli, even though 6 L/min fresh air enters the respiratory system?
Dead space volume reduces the amount of fresh air that reaches the alveoli.
What is the effect of bronchoconstriction on airway resistance and gas exchange?
It increases airway resistance and reduces gas exchange.
What is the ratio of FEV1 to FVC in a normal individual?
At least 80%
What is the effect of hyperventilation on alveolar PO2 and PCO2 levels?
It increases alveolar PO2 and decreases PCO2 levels.
What is the difference between total pulmonary ventilation and alveolar ventilation?
Total pulmonary ventilation includes dead space ventilation, while alveolar ventilation does not.
What is the primary purpose of calculating alveolar ventilation?
To measure the volume of air that participates in gas exchange.
What is the primary function of the vocalisation process in the respiratory tract?
To create vibrations for speech or singing
What happens to the diameter and surface area of the airways as they branch?
The diameter decreases and the surface area increases
What is the purpose of heating the air in the respiratory tract?
To warm the air to body temperature
What is the name given to the portion of the respiratory tract that is enclosed in the thorax?
Thoracic portion
What is the primary function of the defence mechanisms in the respiratory tract?
To remove potentially harmful substances
How many integrated processes does external respiration involve?
Four
What is the primary mechanism by which the respiratory system regulates pH in the blood?
By altering the breathing rate and retaining or removing CO2
What is the primary role of Type II alveolar cells in the lungs?
To produce surfactant to decrease surface tension
What is the primary factor that determines the change in lung volume produced by a given change in the transpulmonary pressure?
The compliance of the lungs
What is the purpose of measuring the FEV1 (Forced Expiratory Volume in 1 second) in pulmonary function tests?
To diagnose obstructive lung diseases
What is the term for the portion of the tidal volume that does not participate in gas exchange in the alveoli?
Anatomical dead space
What is the primary determinant of airway resistance, according to Poiseuille's law?
The radius of the airways
What is the primary reason why the lung compliance is an important factor in determining the ease of expanding the lungs?
Because it affects the magnitude of the change in lung volume produced by a given change in the transpulmonary pressure
What is the primary factor that influences the radius of the airways, according to Poiseuille's law?
The viscosity of the air
What is the effect of decreased lung compliance on the work of breathing?
It increases the work of breathing
What is the primary reason why surfactant is important in the lungs?
Because it affects the surface tension of the fluid lining the alveoli
What is the relationship between the transpulmonary pressure and the change in lung volume?
The transpulmonary pressure is directly proportional to the change in lung volume
What is the primary determinant of the airway resistance, according to Poiseuille's law?
The radius of the airways
What is the primary mechanism by which the movement of the thorax during breathing creates alternating conditions of high and low pressure in the lungs?
The diaphragm descends and the rib cage expands, increasing the volume of the lungs
What is the relationship between the partial pressure of a gas and its movement within the lungs?
The partial pressure of a gas determines the direction of its movement within the lungs
What is the primary function of the extensive network of capillaries in the lungs, in relation to gas exchange?
To facilitate the exchange of oxygen and carbon dioxide between the air and the blood
What is the effect of a decrease in the radius of the airways on air flow, according to the equation Flow ∝ ∆P/R?
Air flow decreases, as the resistance to flow increases
What is the relationship between the pressure and volume of the lungs, as described by Boyle's law?
As the pressure of the lungs increases, the volume of the lungs decreases
What is the primary factor that determines the movement of gases within the lungs, in the context of diffusion?
The partial pressure gradient of the gas
What is the effect of bronchoconstriction on airway resistance?
It increases airway resistance
What is the significance of the ratio of FEV1 to FVC?
It is normally 80% or more
What is the relationship between alveolar ventilation and the amount of fresh air that reaches the alveoli?
Alveolar ventilation is the volume of air that reaches the alveoli
What is the effect of hyperventilation on alveolar PO2 and PCO2?
Alveolar PO2 increases and alveolar PCO2 falls
What is the purpose of calculating total pulmonary ventilation?
To measure the volume of air moved into and out of the lungs
What is the significance of the dead space volume in calculating alveolar ventilation?
It is the volume of air that does not reach the alveoli
Learn about airway resistance, bronchoconstriction, and pulmonary function tests such as FVC and FEV1. Understand how they relate to lung diseases and gas exchange.
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