Cardiopulm Flashcards
Cardiopulm cellular activity:
increased O2 demand
increased CO2 production
cardiopulm circulation activity
increased HR
increased SV
cardiopulm ventilation activity:
increased TV
increased breathing frequency
What is HR
systole to systole
Diastole
relaxation phase
chambers fill
T wave to QRS
Systole
filling phase
chambers expel blood
QRS to T wave
when does atria refilling occur?
ventricular systole
how long does the cardiac cycle last
~0.9seconds or ~67bpm
Cardiac Cycle Phase 1:
Diastole
- ventricular filling: inlet valves open and outlet closed (rapid filling of atria to ventricles)
End Diastolic Volume
what happens for the final filling of the ventricles?
Atrial contraction
Cardiac Cycle Phase 2:
Isovolumetric Contraction
once ventricular pressure rises above atrial, the AV valves close (all valves are closed) thus creating S1 sound –> tensing wall and steep rise of pressure –> ventricular chamber geometry changes to spheroid
Cardiac Cycle Phase 3:
Ejection Phase
- inlet closed, outlet open
- V pressure exceeds atrial
about how much blood is ejected in ejection phase?
3/4 SV
Cardiac Cycle Phase 4:
Isovolumetric Relaxation
- inlet and outlet closed
- ventricle is closed and pressure falls rapidly
- when pressure falls below atrial, AV valves open
what is the purpose of the parasympathetic NS in cardiopulm?
housekeeping; SA node; light-moderate activity
what is the parasym NS innervation of heart?
Vagus N.
what is the purpose of the sympathetic NS in cardiopulm?
homeostasis, responds to various stim
near max and max effort
What are the hormones involved in symp NS in cardiopulm?
catecholamines - epi and norepi
What does norepi do?
increases myocardial contractility and blood flow
SA Node
pacemaker of heart
AV Node
intrincic rhythmicity slower pace than SA; can become dominant under certain circumstances; part of neuromuscular conduction system (Bundle of HIS and right and left bundles)
VO2 Max
Max O2 Consumption - a measure of cardiorespiratory fitness
VO2 Max Equation
VO2 Max = Q * arteriovenous oxygen difference
= SV * HR * AOD
Cardiac Output (Q or CO)
amount of blood pumped out of heart per unit time
cardiac output equation
Q = SV * HR
Stroke Volume (SV)
increases curvilinarly with work rate until reaches near max at about 50% aerobic capacity
SV equation
SV = EDV - ESV = end diastolic volume - end systolic volume
Frank Starling Mechanism
the more blood in the ventricle causes a greater stretch and contraction with increased force
What happens with SV in training?
increases
Heart Rate (HR)
likely will increase due to age due to decreased parasympatheic control
Max is all output effort
HR equation
HR = 220 - age
when does HR typically plateau?
in submax
what does a lower steady state HR do to the heart?
makes it more efficient
what generally happens to HR after 6months training?
decreases 10-30bpm
decreases are highest at greatest workloads
what happens to hr during max effort?
HR remains unchanged or decreases slightly to allow of optimal SV
Ventilation (VE)
is product of TV and breathing frequency
Ventilation equation
VE = TV * f
what happens to VE in min-mod exercise?
VE increases by increasing TV
what happens to VE in vigorous exercise?
increase breathing rate/frequency
What is the respiratory pattern in exercise?
- with light exercise, TV and RR increases up until 70-80% peak exercise
- after 80% peak, only RR increases
Residual Volume Equation
RV = FRC - ERV = (Functional Residual Capacity) - (Expiratory Reserve Volume)
Total Lung Capacity Equation
TLC = FRC + IC (Functional Residual Capacity + Inspiratory Capacity) TLC = RV + VC (Residual Volume + Vital Capacity)
Blood Flow in Exercise
increases at onset to support working skeletal muscle
stabilizes with a constant workload
incremental workload - linear increase
Where is the site of highest vascular resistance in blood flow?
arterioles - due to large pressure drop
Venoconstriction - where does it occur mostly
mostly in arteries; little change in venous resistance
What happens with decreased venous compliance?
increases P within veins and right atrium
increases P different b/n peripheral veins and right atrium
increases P gradient increases venous return to heart
blood flow is _______ proportional to cross-sectional area of vessel
inversely
what happens when tube length doubles
flow decreases by 50%
what happens when tube radius doubles
flow increases 16-fold
what happens when tube viscosity doubles
flow decreases by 50%
Sheer Stress
friction on endothelial wall
size of friction: rate of sliding and fluid viscosity
healthy individuals release nitric oxide
Vascular Tone
the degree of constriction of a blood vessel (relative to max dilated state)
Vasodilatory Capacity -
heart, muscles, skin have increased vascular tone
what happens when blood flow increases
metabolic activity increases
Reactive Hyperemia
blood flow is transiently increasing following a brief period of total ischemia.
What is the intrinsic rate of the SA node?
72bpm
What does the P wave represent?
atrial depolorization
what does the QRS wave represent?
ventricular depolorization
what does the T interval represent?
ventricular repolorization
Functions of the cardiopulm
delivery, removal, transport, maintenance, prevention
Anaerobic Threshold
rise of CO2 is disproportionate to rise of O2
What happens when AT is above threshold
cant sustain prolonged workload
what happens when AT is below threshold?
can maintain exercise comfortably
T/F: you can’t train AT to increase
false: can train
Resting Respiratory Exchange Ration (RER) =
VCO2/VO2
what does a RER of 1.0 mean?
anaerobic metabolism present
what does a RER of 1.9+ generally mean?
indicated max effort
what happens in increasing RER in exercise?
increased CO2 decreased O2
VO2 Max training
can improve 10-30%
what is cardiac output at rest
~5L/min
what is cardiac output in exercise
~20L/min
how does cardiac output increase with workload?
linearly
What happens during exercise for cardiac output?
up to 50% max capacity, there are increases in both SV and HR
after 50%, just primarily due to HR
what is the norm for SV?
100-200 mL/beat
how does SV increase with work rate until near max at 50% aerobic capacity
curvilinearly
what is an important factor in determining individual differences in Vo2 max in considering sedentary vs trained
SV
why do trained people work at a lower hr?
sv
Frank Starling Mechanism
more blood in ventricle causes a greater stretch and contraction with increased force
Ejection Fraction (EF)
proportion blood pumped out of left ventricle each beat
Ejection Fraction Equation
EF = SV/EDV
what is the avg EF in a healthy adult?
60%
Karvonen Formula
[Training Range % * (Max HR - Resting HR)] - Resting HR
HR Recovery
time after exercise for HR to return to resting
what controls ventilation
CO2
what is norm PCO2
40
pulmonary ventilation
gas exchange from high partial P to low partial P
Fick’s Law of Diffusion
the amount of gas that moves across a sheet of tissue is proportional to the area of sheet but inversely to its thickness
What are the properties of air as it is inspired
heated, saturated with water vapor, clean of pollutants
TLC
Total Lung Capacity
the amount of gas in lungs after max inspiration
VC
Vital Capacity
amount gas that can be exhaled after a max inspiration
RV
Residual Volume
amount gas remaining in lungs after max expiration
TV
Tidal Volume
amount gas individual in or expires during normal breathing
IRV
Inspiratory Reserve Volume
amount gas individual can inhale above a tidal inspiration
ERV
Expiratory Reserve Volume
amount gas individual can exhale after tidal expiration
FRC
Functional Residual Capacity
amount gas remaining in lungs after tidal expiration
IC
Inspiratory Capacity
total amount breathed in after norm tidal exhale (get air to go under pool)
FRV
Functional Residual Volume
volume in lungs after norm expiration
VC =
TV + IRV + ERV
amount gas individual can in or expire in normal breaking
TV
amount gas remaining in lungs after tidal expiration
FRC or RC
amount gas individual can inhale above a tidal inspiration
Inspiratory Reserve Volume (IRV)
amount of gas in lungs after max inspiration
TLC
amount gas individual can exhale above a tidal expiration
ERV
total amount breathed in after normal tidal exhale
IC (inspiratory capacity) TV + IRV
amount gas remaining in lungs after max expiration
RV
amount gas remaining in lungs after tidal expiration
FRV
amount of gas that can be exhaled after a deep max inspiration
VC
RV Formula
RV = FRC - ERV
TLC Formula
TLC = FRC + IC = RV + VC
Respiratory Pattern in exercise
- light exercise up to 70-80% peak both RR and TV increase
- after 80% peak, only RR increases
TV plateaus at 50-60% VC
SOA most likely caused by inability to readjust PCO2
dyspnea
increasing ventilation that causes resp alkalosis
hyperventilation
breathing technique to trap and pressurize air in lungs;
if held too long, decreases Q
Valsalva Maneuver
What do respiratory muscles do in performance?
use more than 15% of total O2 consumed and fatigue later
what happens when H+ increases?
respiration increases and then more CO2 released
What happens with exercise with people with pulmonary disease?
- ventilation limitation
- decreased max vent volume
- diminished lung volumes
- increased dead space
What are the objectives in exercise training?
- increase fxnal capacity
- increase fxnal status
- decrease severity of dyspnea
- improve QOL
A-V O2 difference
O2 difference between arteriol and venous blood
what is normal resting A-V O2 difference?
exercise?
5ml/O2/100ml/dl
15
why does blood volume typically increase
plasma volume increase
what happens in training for long term endurance
increase VO2max
decrease HR
Blood Pressure Equation
BP = Q * total peripheral resistance
normal acute BP responses to exercise
increase SBP
no change DBP
MAP slightly increases
TPR decreases - vasodilation of exercised muscles
what is the long term control of BP
kidneys
what is the short term control of BP
cardiovascular system
MAP equation
MAP = Q * TRR
