Lecture 2- Mechanics of breathing and gas exchange Flashcards
compliance is regulated by … and …
lung elasticity
surface tension
compliance is the inverse of …. and is indicative of the amount of … … needed to ventilate the lung
stiffness
muscle force
if you increase surface tension, then you … pressure
increase
if you decrease radius, you … pressure
increase
surfactant reduces … … by decreasing density of water molecules at air-water interface
surface tension
surfactant is an …. …. + protein molecule that forms a monolayer between air and water
amphipathic phospholipid
T/F surfactant has a greater effect in larger alveoli than small
false. greater effect on small
surfactant does not create additional surface tension and will … compliance
increase
production of surfactant is regulated by … receptors in type 2 cells; so … breathing increases surfactant production
stretch
deep
which is more important in increasing lung compliance?
overcoming surface tension
lung elasticity
overcoming surface tension
what is the 2nd leading cause of death in premature infants?
ARDs
surfactant deficiency leads to…
respiratory distress
whats is the therapy for ARDs?
mechanical ventilation and artificial surfactant
if resistance is increased than you breathe more …. to increase change in pressure.
You breathe more … because airflow during expiration is limited
deeply
slowly
if compliance is decreased then you breathe more … to compensate for reduced change in volume and change in pressure.
You breathe more …. to minimize muscle effort
rapidly
shallowly
… causes increased airway resistance because of inappropriate contraction of smooth muscle
asthma
how can asthma be treated
glucocorticoud therapy and/or bronchodilators
… increases airway resistance and is often associated with smoking
COPD
…. is a disease where the alveolar tissues are damaged or destroyed perhaps due to overproduction of proteolytic enzymes
emphysema
emphysema results in airway …, lack of … and difficulty in …
collapse
recoil
expiring
… is when mucus or inflammation impairs airflow and this leads to increased … and … breathing
chronic bronchitis
resistance
deeper
inspiratory reserve volume is …. x the tidal volume
6x
expiratory reserve volume is …. x the tidal volume
3x
… volume is the amount of air that stays in the lungs after maximum expiration
residual
clinically relevant measures of lung volumes
vital capacity
forced expiratory volume in 1 second (FEV1)
in a healthy lung, FEV1 is usually … % of vital capacity
80%
equation for vital capacity?
IRV+ERV+TV
~5000ml
equation for total lung capacity?
vital capacity + residual volume
~6000ml
in obstructive lung diseases, FEV1 is … and vital capacity is …
decreased
normal
in restricted lung disease, FEV1 is … and vital capacity is …
normal
decreased
the equation for minute ventilation is…. but not all air reaches alveoli so must consider …
resp. rate x tidal V
anatomical dead space is about …. ml
150ml
the equation for alveolar ventilation
(tidal V- dead space) x respiratory rate
which is better at increasing alveolar ventilation?
increasing resp. rate or increasing tidal volume?
and why?
increasing tidal volume (because of the anatomical dead space)
alveolar deadspace exists when there is a mismatch between … and …
ventilation and bloodflow
alveolar dead space is always greater than…. even in normal lungs due to the effects of … on bloodflow
zero
gravity
… dead space is the sum of anatomical dead space and alveolar dead space
physiologic
… Law says that for a mixture of gases, the total pressure is the sum of the individual (partial) pressures
Dalton’s
Dalton’s law states that a pressure exerted by a gas is …. of pressure exerted by other gases
independent
… Law states that the amount of gas dissolved in a liquid is proportional to the partial pressure of that gas in equilibrium with the liquid
Henry’s
partial pressure vs. concentration of a gas in a liquid depends on …. (3)
which gas it is
partial pressure of the gas
temperature
what 3 things affect alveolar PO2?
atmospheric PO2
rat of alveolar ventilation
rate of cellular O2 consumption
… is when ventilation is decreased relative to metabolism.
So there will be a … in alveolar PO2 and a … in alveolar PCO2
hypoventilation
decrease
increase
…. is when ventilation is increased relative to metabolism
So there will be a …. in alveolar PO2 and a … in alveolar PCO2
hyper ventilation
increase
decrease
as you go to higher altitudes, the partial pressure of … decreases so it is not able to diffuse as easily into the lungs because there is less of a pressure gradient
oxygen
equation for lung compliance
change in volume of lung / change in pressure (ptp)
… is the measure of the intermolecular attractive forces that stabilize liquid. these forces pull molecules together at the air-liquid interface
surface tension
for polar molecules like water, surface tension is created by ….
electrostatic force
alveoli are connected to e/o so the smallest ones are at a greater risk of …
collapsing
COPD is a result of these 2 conditions together
emhysema
chronic bronchitis
Tidal volume is about … mL and is the volume entering lungs per breath
500ml
inspiratory reserve volume is the max inspired and it is about
3000ml
expiratory reserve volume is the volume exhaled past TV and is about….
1500ml
residual volume is the volume in lungs after MAX expiration and its about
1000ml
partial pressure of O2 in air
160
partial pressure of O2 in alveoli
105
partial pressure of CO2 in air
0.3
partial pressure of CO2 in alveoli
40
partial pressure of O2 in alveolar venous capillaries
40
partial pressure of CO2 in alveolar venous capillaries
46
partial pressure of O2 in systemic arteries
100
partial pressure of CO2 in systemic arteries
40
partial pressure of O2 in tissues
less than 40
partial pressure of CO2 in tissues
greater than 46
partial pressure of O2 in veins
40
partial pressure of CO2 in veins
46
