respiration 2 Flashcards
what determines the volume of air in the lungs
magnitude of the pressure change during inspiration and expiration
stretchability of the lung
what is the stretchability of the lung
lung compliance
what is the math of lung compliance
change in volume/transpulmonary pressure (i.e. change in pressure)
what is compliance the inverse of
Stiffness
what are the parts of compliance
Lung elasticity
Surface tension
how does volume change as pressure increase in high elastic lungs
volume increases rapidly
what is surface tension
Measure of the intermolecular attractive foces that stabilize liquid
- pulls molecules together at air-liquid interface
what creates force in surface tension for polar molcules
Electrostatic force
is force strong on the liquid of air side
Strong on the liquid side
what does the difference in force do to water molcules for surface tension
pulls surface molecules toward the water phase, reducing surface area
- remaining surface molcules exert an opposing force called surface tension
how many air water interfaces are there in bubbles
Two air-liquid interfaces
what is the inner presssure of bubble in relation to surface tension and radius
2 x surface tension/radius
directly proportional to surface tension
indirectly proportional to radius
how does air flow from two different sized bubbles
air flows from the small bubble to the large bubble
what does the body do to help overcome the surface tension of the lungs
surfactant produced by type II cells
how does surfactant reduce surface tension
reduces intermolecular forces between water molecules
how does surfactant secondarily increase surface area
alveoli now can be small and numerous and increase surface area
what is surfactant as a chemical
amphipathic phospholipid and protein molecule forming a monolayer between air and water
why does surfactant hang out near the surface
hydrophilic/hydrophobic interactions
does surfactant have greater effect in small or large alveoli
larger effect in small
what regulates production of surfactant
stretch receptors in type II cells
- deep breathing
what is more important to overcome to support breathing, surface tension or lung elasticity
surface tension more important
what does surfactant deficiency lead to
respiratory distress
what is the 2nd leading cause of death in premature infants
acute respiratory distress syndrom
what are the symptoms of acute respiratory distress syndrome
Insufficient surfactant production
lungs resist expansion
how does one treat acute respiratory distress syndrome
artifical surfactant
mechanical ventilation
how is resistance in the airway related to airflow
inversely raised to the 4th
what besides radius controls airway resistance
Transpulmonary pressure
Elasticity of tissues between outside of airways and alveolar walls opens airways during inspiration
neural and chem control of smooth
what does transpulmonary pressure do to the airway resistance
dilates bronchial during inspiration
how does the body respond to an increase in resistance
- breath more deeply to increase a change in pressure
- breathe more slowly b/c airflow during expiration is limited
how does the body respond to compliance
breathe more rapidly to compensate for reduced change in volume and pressure
breathe shallow to minimize effort
what does asthma do to the lungs
Increased airway resistance due to inappropriate contraction of smooth muscle
how does one treat asthma
glucocorticoids
bronchodilators
what is emphysema
alveolar tissues damaged/destroyed due to overproduction of proteolytic enzymes
what happens in emphysema grossly
airway collapse
lack recoil
difficult expiring
what happens in chronic bronchitis
mucus or inflmmation impairs airflow leading to deeper breathing due to increased resistance
what is the tidal volume
Volume of air entering the lungs per breath
volume of the tidal volume
500ml
what is the inspiratory reserve volume
the max volume inspired
what is the volume of inspiratory reserve volume
about 3000ml
what is the expiratory reserve volume
volume exhaled beyond tidal vlume
what is the volume of expiratory reserve volume
1500ml
what is the residual volume
volume in the lungs after maximum exhalation
what is the volume of residual volume
about 1000 ml
what is vital capacity
Inspiratory reserve volume
+ tidal volume
+ expiratory reserve volume
what is the vital capacity volume
5000 ml
what is the total lung capacity
vital capacity+ residual volume
what is the volume for the total lung capacity
6000ml
what measures of lung volume is relevant
Vital capacity
Forced expiratory volume in 1 sec
what are the clinical measures changed in obstructive lung disease
Decreased forced expiratory volume in 1 sec
normal vital capacity
what are the clinical measures changed in restrictive lung disease
decreased vital capacity
normal forced expiratory volume in 1 sec
what is the equation for minute ventilation
tidal Volume x respiratory rate
what is the anatomical dead space
the air that remains in the conducting airways
volume of the anatomical dead space
about 150ml
what is the best measure of alveolar ventilation
includdes the anatomical dead space
what is equation for alveolar ventilation
(tidal V- dead space) x respiratory rate
does increasing tidal volume or respiratory rate have a larger effect on alveolar ventilation
increasing tidal volume
when can alveolar dead space exist
when there is a mismatch between ventilation and blood flow
- no blood supply to alveolus
- reduced blood supply to alveolus
is alveolar dead space ever zero
No, even in healthy lungs, the alveolar dead space is greater than zero due to GRAVITY
what is physiologic dead space
anatomical dead space + alveolar dead space
external respiration
gas exchange between air and blood in pulmonary capillaries
what is internal respiration
gas exchange between blood in systemic capillary and cells (interstitial fluid)
what are the steps of respiration
Ventilation (bulk flow) external respiration (diffusion) gas transport in blood (bulk flow) internal respiration (diffusion) Cellular respiration - consume O2 and CO2
Dalton’s law
mixture of gases total pressure is the sum of individual pressure
what individual pressure of a gas in a mixture
Partial pressure
Henry’s law
amount of gas in a liquid is proportional to the partial pressure of the gas in eq with the liquid
what does the pressure of the gas in a liquid phase equal
the pressure of the gas in the gas phase
partial pressure as a function of concentration of a gas in liquid depends on what
which gas it is
Partial pressure of gas
temo
partial pressure of O2 and CO2 in the air
PO2: 160
PCo2: .3
partial pressure of O2 and CO2 in the alveoli
PO2: 105
PCo2: 40
partial pressure of O2 and CO2 in the arteries
PO2: 100
PCo2: 40
partial pressure of O2 and CO2 in the interstial fluid
PO2: less than 40
PCo2: greater than 46
partial pressure of O2 and CO2 in the veins
PO2:40
PCo2: 46
what determines alveolar PO2
atmospheric Partial pressure of O2
Rate of alveolar ventilation
Rate of cellular O2 consumption
what does breathing air with low PO2 do to alveolar PO2 and Alveolar PCO2
Alveolar PO2: decrease
Alveolar PCO2: no change
what does an increase in alveolar ventilation and unchanged metabolism do to alveolar PO2 and Alveolar PCO2
Alveolar PO2: increase
Alveolar PCO2: decrease
what does a decrease in alveolar ventilation and unchanged metabolism do to alveolar PO2 and Alveolar PCO2
Alveolar PO2: decrease
Alveolar PCO2: increase
what does an increase in metabolism and unchanged alveolar ventilation do to alveolar PO2 and Alveolar PCO2
Alveolar PO2: decrease
Alveolar PCO2: increase
what does a decrease in metabolism and unchnaged alveolar ventilation do to alveolar PO2 and Alveolar PCO2
Alveolar PO2: increase
Alveolar PCO2: decrease
what does a proportional increase in metabolisma and alveolar ventialtion do to alveolar PO2 and Alveolar PCO2
Alveolar PO2: no change
Alveolar PCO2: nochange
hypoventiatlion
Ventilation decreased releative to metabolism
how does hypoventilation affect alveolar PO2 and Alveolar PCO2
decrease alveolar PO2
Increase alveolar PCO2
hyperventialtion
Ventilation increased relative to metabolism
how does hyperventialion affect alveolar PO2 and Alveolar PCO2
increase alveolar PO2
decrease alveolar PCO2
does hyperventilation occur in exercise
No
what happens to alveolar PO2 at high altitude
Decreases
does compromising the lung’s gas exchange affect O2 or CO2
affects O2 more (a bigger problem
what can compromise gas exchange in the lungs
Disease
Strenuous exercise
what part of the lung has greater perfusion and what
Lower part of the lung is greater because of gravity
what are the sources of inequalities of ventilation and perfusion
Vascularized space with no ventiatlion
Ventilated space with no blood supply
what is the response due to decreased airflow to region of a lung
drop of Pulmonary blood O2
vasoconstriction
decreased blood flow to badly ventilated part of lung
what is the response due to a decrease in blood flow to a region of lung
decreases alveoli PCO2
bronchocontrscition
decreased airflow to the poorly vascularized part of lungs