Respiratory Phys: Ventilation and Mechanisms of Breathing Flashcards
Define ventilation
the volume of air moving into or out of the lungs
*usually expressed as a rate
What are the 5 steps of respiration?
- ventilation
- exchange of O2 and CO2 btwn alveolar air and capillaries by diffusion
- Transport of O2 and CO2 thru pulm and systemic circulation
- Exchange of O2 and CO2 btwn blood in tissue capillaries and cells in tissues by diffusion
- Cellular utilization of O2 and production of CO2
Define TLC
total lung capacity
-Max expiration volume + residual volume
Define TV
Tidal Volume
-volume of a normal breath
Define FRC
Functional Residual Capacity
-volume of air left in lungs after normal expiration
Define RV
Residual Volume
-volume of air left after max expiration
Define VC
Vital capacity
-volume of max expiration
Define FVC
Forced vital capacity
-volume of air that is exhaled during a forceful expiration
Define FEV1
Forced Expiratory Volume in 1 second (with max inspiration)
-normal ~80%
lung DZ in which air cannot get out
obstructive lung disease
-asthma, emphysema
lung DZ in which air cannot get in
restrictive lung disease
-obesity, pulmonary fibrosis
How is FEV1:FVC ratio affected in obstructive lung disease? Restrictive?
obstructive: the ratio decreases because expiration is blocked
Restrictive: normal (both FEV1 and FVC decrease proportionally bc less it able to be inhaled)
What are 3 factors for determining lung volumes?
gender, weight, age
What is the anatomical dead space?
volume of air in the conducting pathways that is not available for gas exchange
What is alveolar dead space?
volume of alveolar space not available for gas exchange due to lack of blood supply. Always pathologic!!
What is physiologic dead space?
sum of anatomical dead space and alveolar dead space
What is the difference between minute ventilation and alveolar ventilation?
minute = amount of air moved in and out of lung (aka total ventilation) per min
alveolar = amount of air moved in and out of lung - dead space per min
What type of breathing is more effective for increasing alveolar ventilation? Why?
slow deep breaths that will increase in TV with dec RR
Alveolar ventilation = (TV x RR) - (dead space volume x RR)
What is the driving force that moves air into and out of the lungs?
the pressure difference between the alveoli and the mouth ( aka atmosphere)
What is the trans-respiratory system pressure?
pressure difference between the alveoli and the atmosphere (i.e. what determines the flow of air)
Prs = Palv - Patm
What is the transpulmonary pressure (aka transmural pressure)?
pressure diff between the alveoli and the intra pleural pressure
Ptp = Palv = Pip
Compliance relates:
the change in volume of a closed system to the change in pressure distending it