Pulmonary Dynamics Flashcards
Breathing is essential to the
bioenergetic processes of life.
What are purposes of breathing?
1: Exchange of O2
2: Exchange of CO2
3: Control of Blood Acidity
4: Oral communication
Where is O2 and CO2 exchanged?
Alveoli between the atmph and blood.
Process of ventilation results in Higher PO2 in _____ compared to _____
lungs
metabolizing tissues.
What affects the amount of O2 and CO2 exchanged between body and atmosphere?
Speed and depth of breathing.
movement of air in and out of lungs?
Ventilation
Cellular utilization of O2
Respiration.
How are inspiration and expiration regulated?
Frequency and Volume.
VDS=
deadspace= 150 mL
VA=
alveolar ventilation=
(V1-VDS)xF
VT=
Tidal volume=
VA+VDS
or
VE/F
VE=
Minute Ventilation=
VTxBF
It is more efficient to Breathe
Deep and less often.
increases VT and decrease F
What consumes O2 for work of breathing? what does this result in?
Respiratory muscles.
less O2 for exercising muscles.
Rate and depth of breathing are adjusted in response to
Body’s metabolic needs.
What is regulated at resting values regardless of exercise intensity?
PaO2
PaCO2
pH
Results from inherent and automatic activity of inspiratory neurons?
Where are the cell bodies of these neurons?
Respiratory cycle.
in the medulla.
Inhalation is a ____ process
Expiration is a ___ process.
Active
Passive (recoil)
Specialized neurons that monitor blood conditions and provide feeback?
Chemoreceptors
Regulated by the chemical state of blood at rest?
Pulm ventilation.
Reduced O2 pressures stimulate ___ ? for what?
aortic and carotid chemoreceptors to increase ventilation.
What is the only protection against decrease in PaO2
Peripheral Chemoreceptors.
Peripheral chemoreceptors stimulate ventilation in response to
Decreased PaO2 Increase PaCO2 Temo Metabolic acidosis Decrease in BP Change in H+ exercise.
At rest for healthy ppl, most important stimulus is
why?
CO2 pressures.
increase in PaCO2 cause large increase in VE
Central chemoreceptors location and what they respond to
medulla
PaCO2 and H+
What are phases of Control during exercise?
Rapid Rise
Rise to steady state
Steady State
Recovery.
What happens in phase 1 of control during exercise?
neurogenic stimuli from cortex combine with feedback from active limbs stimulate medulla to increase ventilation. ^VE
What happens in phase 2 of control during exercise?
What is it regulated by?
ventilation rises to steady state.
regulated by cortex and intrinsic neurons on respiratory control center.
What happens in phase 3 of control during exercise?
fine tuning of steady state through peripheral chemoreceptors and cortex.
VE matches CO2 production.
What happens in recovery phase of control during exercise?
initial rapid decrease because of removing cortex and movement.
slows due to removal of short term potentiation of respiratory center.
What effects VE, VO2 and VCO2 more than any other form of physiologic Stress
Physical activity.
increases to maintain the proper gas concentrations for rapid gas exchange.
alveolar ventilation.
in light/mod exercise. ventilation is increased through increasing ____
what takes on important role at higher level?
ventilation increases ____
VT
Breathing frequency.
linearly with VO2
Ventilation averages ____ of air for each _____ of oxygen consumed.
20-25 L
1 Liter
Ratio of VE to VO2?
equation
Ventilatory equivalent
VE/VO2
25:1 at submit exercise.
In steady state, VO2 and VE ___
plateu
at more intense exercise: ventilation increases__
VE/VO2=
disproportionately with VO2
35:1
Exercise level that LA begins to show a systemic increase above resting baseline levels?
Onset of blood lactate accumulation (OBLA)
4.0mM
at submax levels O2 delivery to muscles can no longer support requirement of oxidation thus more E is derived from
glycolysis.
OBLA in trained vs untrained.
70% VO2 max
55-65% VO2 max.
almost all of the LA generated during anaerobic metabolism is buffered in the blood by____
what are byproducts.
NaHCO2 and byproducts are: Sodium lactate/H2O/CO2
Co2 gets exhaled.
OBLA relates to the onset of
anaerobiosis and accumulation of LA
What is mechanism for rise of VE in submac exercise/ non-steady state?
Breathing frequency.
point where VE and VCO increases disproportionately to V02 during graded exercise. Also known as the
Ventilatory threshold
Anaerobic threshold.
describes the highest V02 or exercise intensity before a 1.0mM increase in blood lactate concentration above the pre-exercise level.
lactate threshold.
More muscle mass that is used, OBLA will occur at a
higher VO2
Influence and predict endurance performance
VO2max and OBLA
Training can be improved to point of
OBLA w/o increase to VO2.
Factors of OBLA
Muscle fiber type
Capillary Density
Mitochondria Size + #
alteration of muscle’s enzyme and oxidative capabilities.
Factors of VO2 max
absolute quantity of muscle mass activated
Functional capacity of Cardiovascular system
The exercise intensity at the point of OBLA is a consistent and powerful predictor of
performance in aerobic exercise.
changes in training related to bola not VO2
Less adaptation in pulmonary structure and function occurs in aerobic training than
Cardiovascular and neuromuscular function.
Ve max increases with
increase in VO2 max
At submax
Ventilatory equivalent___
VT becomes ______
and Breathing Frequency is ____
decreases
larger
reduced.
Who is ventilation a factor in limiting aerobic capacity for?
elite athlete.
Greater capacity to increase ventilation during aerobic exercise than
Q (6fold)
VO2 (20 fold)
ventilation is (35 fold)
VE max in healthy individuals during max aerobic exercise?
60-85% of Max voluntary ventilation. MVV
health individuals have MVV reserve of
20-40%
n COPD, the added expiratory resistance ____ normal cost of breathing at rest and severely limits
triples.
the exercise capacity of individuals.
In severe COPD the energy cost of breathing attains of the total exercise V02.
40%
Exercise training produces only small improvements in PFT but increases
exercise capacity
reduces dyspnea
improve respiratory and peripheral muscle function
enhance psychologic state.
Cigarette smoking the exercise HR response
why?
BLUNTS
due to altered sensitivity in ANS control.
