Lab 2 prep Flashcards
cardiac output (Q) calculation
Q = SV x HR
ventilation (Ve) calculation
Ve = Freq x tidal volume
increase demand for energy on total peripheral resistance (TPR)
decreased TPR
- vasodilation
Fick Equation
increased O2 uptake
VO2 = a-v O2 difference x Q
- difference between arteriole O2 and venous O2
- how much O2 is utilized
average # of breathes per min
~16 breaths per minute
average resting Ve (ventilation)
- calculation
8 L/min
- Vt x breaths per min
- 500mL x 16 breaths per min
maximum Ve (ventilation)
150 L/min - 200 L/min
- depending on fitness level
changes in respiration with increasing power output
- Vt and Freq
Tidal Volume (Vt) - linear increase and plateau
Freq
- no initial increase
- linear increase as Vt plateaus
what effects rate of breathing
increase [CO2]
how Ve increases with increase power output
- steady linear increase
- break point
- steeper linear increase
Q at rest
- calculation
Q = 6.0 L/min
- HR x SV
- 75b/min x 80mL/beat
*recreationally trained indv
Q during exercise
Q = 25.0 L/min
- HR x SV
- 200b/min x 125mL/beat
*recreationally trained indv
SV average range
80mL (rest) - 125mL (exercise)
- recreationally trained individual
HR vs. power output
linear increase
- 75-200 bpm
max HR
220 - age
Stroke volume vs. power output
steep linear increase
- early plateau
- lower continued increase in athletes
Q, HR and SV of a world class athlete
Range
- SV ~120- 200mL (avg 80-125mL)
- HR ~50-200bpm (avg 75-200bpm)
Max
- Q ~40L/min (avg 25L/min)
*nearly double
peripheral blood flow
- % to muscle at rest vs exercise
Rest
- 25% goes to muscle
Max Exercise
- 85% goes to muscle
Muscle blood flow (MBF)
- at rest and exercise
rest MBF = 1.5 L/min
- 25% x 6L/min
exercise MBF = 21 L/min
- 85% x 25L/min
Systole and diastole BP
- rest + exercise
Systole
- 120-200
diastole
- 80 (incr/decr w exercise)
mean arteriole pressure calculation
rest
- 2/3 diastole + 1/3 systole
exercise
- (SBP + DBP) / 2
BP calculation
Q x TPR
TPR calculation and avg measures
TPR = MAP / Q
Rest
~16.7 PRU
= 100mmHg / 6L/min
Exhaustion
~4.8 PRU
= 120mmHg / 6L/min
*lowers with exercise
how to calculate VO2 given power output
equation
- calculated avg from data of large sample
- (wont need to know)
VO2 = (0.01141 x PO) + 0.435
how to estimate Q given VO2
`Q = (5 x VO2) + 5
*relationship holds for all people (even top athletes)
Vatps meaning
volume at ambient temperature pressure saturation
- calc in air
- must be corrected
Vstpd meaning
volume at standard temperature pressure dry
- corrected with water vapour pressure
- always lower than Vatps
ECG
- why Q and S waves are negative waves
slight conduction towards negative electrode (anode)
- negative inside the cell, positve
Q - delay at the AV node
S - depol through basal regions of the heart, up around purkinjie fibres
ECG
- why is T wave positive
repolarization towards negative electrode
- negative wave to negative cell
ECG
- why is R wave so big
ventricle large number of cells
- synchronized, depol at same time
ECG
- direction of repol
repol on an angle
- not perpendicular
ECG
- why not talk about atrial repol
atrial repol covered by ventricular depol
ECG
- depol and repol in atria and ventricles
Atria
- 1st to depol, 1st to repol
Ventricles
- 1st to depol, last to repol
ECG
- common problem in athletes
premature ventricular contraction
- ventricles contract before AV node firing
- low resting HRs
- goes away with exercise (incr. HR)
