Cardiovascular Physiology
What is the equation for cardiac output, and what are the resting normal values for each variable?
(CO) = heart rate (HR) × stroke volume (SV)
HR= 60-100 beats per minute
SV = 60-80 milliliters per beat for SV
70bpm x 70ml ~ 1400ml/min = 5L/min CO
What tissues are you measuring when you use the skinfold caliper?
subcutaneous fat
Define exercise tolerance and why is it important?
Exercise tolerance is the tolerable duration that a task can be sustained, in the lab we tested this by biking at a constant power bout till the participant could not sustain that level.
Exercise tolerance is important because it evaluates the functions of a patient's physiological systems and is the strongest predictor of mortality in healthy people and people with a variety of cardiopulmonary diseases
If a participant cycles at 150 W with a cadence of 70 rpm, what should the resistance (kp) be on a Monark ergometer?
150W = kp x 70rpm
150W/70rpm = 2.1kp
Basket = 1kp
Added = 1.1 kp
If a participant cycles at 150 W with a cadence of 70 rpm, how much resistance (kp) are you adding on the Monark ergometer?
150W = kp x 70rpm
150W/70rpm = 2.1kp
Basket = 1kp
Added = 1.1 kp
What is the normal resting blood pressure for a healthy adult, and what do the first and last Korotkoff sounds indicate?
Normal resting BP = less than 120/ less than 80
First sound = systolic
Second sound = diastolic
Where do you place ECG leads V1 and V2?
On either side of the sternum at the 4th intercostal space.
What is a normal VO₂ at rest and how does it change during exercise?
VO₂ at rest is ~3.5 mL/kg/min that is equivalent to 1 MET and increases proportionally with workload.
What are MIP and MEP used to evaluate and what are the corresponding muscles that are being targeted for each?
Evaluate Inspiratory and Expiratory muscle strength.
MIP = Maximal Inspiratory Pressure (Diaphragm & External Intercostals)
MEP = Maximal Expiratory Pressure (Abdominal & Internal Intercostals)
True or False: A sedentary 48-year-old male smoker can perform a 3-minute all-out test.
False
Sedentary +1
Smoker +1
Age +1 Male >35 years
How does systolic and diastolic blood pressure typically change during cycling exercise?
systolic: It increases gradually with intensity.
diastolic: It remains stable or slightly decreases.
If you have a 10 s rhythm strip from a patient, how can you calculate their heart rate quickly?
If you have a 10sec rhythm strip from a patient, you can quickly calculate their heart rate by counting the number of QRS complexes and multiplying by 6.
EX: 10 QRS complexes x 6 = 60bpm
Why must steady-state be reached before recording BP during exercise?
When someone starts exercising, their heart rate, blood pressure, and ventilation all start changing quickly. Those early minutes aren’t stable, variables are fluctuating as the body is still adjusting to the new workload.
What is the equation for minute ventilation, and what are the resting normal values for each variable?
Minute ventilation: the total volume of air that is inhaled and exhaled from the lungs in one minute.
VE = Tidal Volume x Breathing Frequency
Tidal volume = 0.5L to 1.0L
Breathing Frequency = 12 - 20 bpm
VE = 0.5L x 12bpm = 6L/min
Where do dispose of the following:
1. Lancet
2. Lactate strip
3. Gloves
4. Gauze
5. Alcohol swabs
Lancet -> sharps container
Lactate strip -> sharps container
Gloves -> dry biological wastes bin
Gauze -> dry biological wastes bin
Alcohol swabs -> regular trash
What happens to stroke volume and heart rate when a person goes from lying down to standing up, and why?
When moving from supine to standing, gravity pulls blood down toward the lower extremities.
This causes less venous return (less blood returning to the heart), which leads to a decrease in stroke volume (SV).
To maintain cardiac output (Q = HR × SV), the body compensates by increasing heart rate (HR).
What are the three common sites used for the 3-site skinfold test in females, and what is the direction of the skinfold (vertical, diagonal, or horizontal) at each site?
Triceps – Vertical fold halfway between the shoulder and elbow on the back of the upper arm.
Suprailiac – Diagonal fold just above the iliac crest along the natural line of the skinfold (angled downward toward the groin).
Thigh – Vertical fold on the anterior midline of the thigh, halfway between the hip and the top of the patella.
True or False: If a task requires a power output below critical power, it is possible to predict how long someone can sustain that task.
False: Below this threshold, energy systems can meet the demand without a progressive loss in performance, so the task is considered theoretically sustainable.
During gas calibration, the following values are measured: room air contains approximately 20.95% O₂ and 0.04% CO₂, while a gas tank sample shows 16% O₂ and 4% CO₂. Explain what these values represent in terms of inspired and expired air, and why the differences exist.
Room air (20.95% O₂, 0.04% CO₂) → represents inspired air.
Gas tank sample (16% O₂, 4% CO₂) → represents expired air.
Reason for differences:
Oxygen is consumed by the body during metabolism, so O₂ decreases in expired air.
Carbon dioxide is produced by metabolism, so CO₂ increases in expired air.
What is residual volume and what is a good estimate value for RV?
Residual volume is the amount of gas left in your lungs after a maximal expiration. A good estimate is around 1 to 1.2 liters.
During exercise, your body constantly modulates blood vessel resistance and flow through which two mechanisms?
Vasodilation and vasoconstriction.
Name the electrical deflection that corresponds to each of the following ECG waves: P wave, QRS complex, and T wave.
atrial depolarization (P-wave)
ventricular depolarization (QRS complex)
ventricular repolarization (T-wave)
Define critical power.
Critical Power (CP): is the highest sustainable power output that can be maintained without fatigue for an extended duration. It separates exercise intensity domains into:
Unsustainable (above CP): anaerobic reliance, inevitable fatigue.
Sustainable (below CP): steady-state energy systems, theoretically indefinite duration.
During gas calibration, the following values are measured: room air contains approximately 20.95% O₂ and 0.04% CO₂, while a gas tank sample shows 16% O₂ and 4% CO₂. Explain what these values represent in terms of inspired and expired air, and why the differences exist.
Room air (20.95% O₂, 0.04% CO₂) → represents inspired air.
Gas tank sample (16% O₂, 4% CO₂) → represents expired air.
Reason for differences:
Oxygen is consumed by the body during metabolism, so O₂ decreases in expired air.
Carbon dioxide is produced by metabolism, so CO₂ increases in expired air.
What does RER stand for and what does it represent?
Respiratory Exchange Ratio = V̇CO₂ / V̇O₂; reflects substrate utilization.
RER > .7 carbohydrate metabolism
RER <.7 fat metabolism