Alveolar Ventilation Flashcards
Total lung capacity, functional residual capacity and residual volume can be measured using which techniques
Helium-Dilution
Nitrogen-washout
Body Plethysmograph
How do you calculate Minute Ventilation or Total Ventilation
VT x RR
How do you calculate Dead Space Ventilation
VD x RR
How do you calculate Alveolar Ventilation
(VT – VD) x RR
What is Dead Space Ventilation
air that never reaches the gas exchange areas
What is Alveolar Ventilation
the rate at which new air reaches gas exchange areas
The anatomic dead space can be determined by using _______method
Fowler’s
What is Alveolar Dead Space
the volume of gas that enters unperfused alveoli per breath
Physiologic dead space can be measured using _______ method
Bohr method
What is the equation for Dalton’s Law of Partial Pressure
Px = Fx × Ptot
What is the alveolar gas equation
PAO2 = PIO2 – PACO2 / R
= FIO2 (PB – PH2O) – PACO2 / R
Hypoventilation always \_\_\_\_\_\_ (increase/decrease) the alveolar and arterial PCO2
increase
Hypoventilation _______ (increase/decrease) Decreases the PO2 unless additional O2 is inspired
decrease
True or False
Hypoxemia induced by simple hypoventilation is easy to reverse by adding O2 to the inspired gas
True
What is alveolar ventilation
the volume of fresh air entering the alveoli per minute or leaving the body per minute
The size of a person’s lungs depends on
height and weight or body surface area, as well as on his or her age and sex
What are the 4 standard lung volumes
tidal
residual
expiratory reserve
inspiratory reserve
What are the 4 standard lung capacities
functional residual
inspiratory residual
total lung
vital
What is tidal volume
the volume of air entering or leaving the nose or mouth per breath
What controls the tidal volume
respiratory control centers of the brain
What is residual volume
the volume of gas left in the lungs after a maximal forcedexpiration
Which force determines residual volume
the force generated by the muscles of expiration and the inward elastic recoil of the lungs as they oppose the outward elastic recoil of the chest wall
What is the expiratory reserve volume
the volume of gas that is expelled from the lungs during a maximal forced expiration that starts at the end of a normal tidal expiration
Expiratory reserve volume is the difference between
he functional residual capacity (FRC) and the residual volume (RV)
What is the inspiratory reserve volume
the volume of gas that is inhaled into the lungs during a maximal forced inspiration starting at the end of a normal tidal inspiration
What force determines the inspiratory reserve volume
the strength of contraction of the inspiratory muscles, the inward elastic recoil of the lung and the chest wall, and the starting point
What is the functional residual capacity
the volume of gas remaining in the lungs at the end of a normal tidal expiration
What is the inspiratory capacity
the volume of air that is inhaled into the lungs during a maximal inspiratory effort that begins at the end of a normal tidal expiration (the FRC)
total lung capacity
the volume of air in the lungs after a maximal inspiratory effort
vital capacity
the volume of air expelled from the lungs during a maximal forced expiration starting after a maximal forced inspiration
The nitrogen washout technique is used to determine
the person’s initial lung volume
How is the initial lung volume calculated using the nitrogen washout technique
Total volume expired×% N2 =original volume of N2 in lungs
then : Original volume of N2 in lungs×1.25=original lung volume
helium dilution technique is used to determine
the functional residual capacity
What is the formula used to determine FRC by the helium dilution technique
total amount of He before test = total amount of He at end of test:
FHEi x Vspi =FHEf (Vspf +VLf)
The body plethysmograph is a technique used to determine
functional residual capacity.
The “anatomiic dead space” corresponds to which section of the respiratory system
the conducting region
What is known as the physiological dead space
anatomic dead space plus the alveolar dead space
What is the closing volume
The lung volume at which airway closure begins to occur
