Exercise Physiology: Final Exam

Systolic (SBP) is referred to as

The top number (higher pressure) occurring during ventricular contraction indicating pumping of the heart.

Diastolic (DBP) is…

The bottom number (lower pressure) that occurs during ventricular relaxation indicating filling of the heart

What contracts during ventricular relaxation?

Atria

What contracts during atrial relaxation

ventricles

P-Wave 

Atrial depolarization

Causes contraction for QRS complex to start

QRS Complex

Ventricular depolarization

Apart of contraction

T-Wave

Ventricular Repolarization

Follows contraction, with relaxation

Physiological variable changes with incremental exercise

Cardiac output, Heart rate (Regulating Factor), and Stroke Volume

Cardiac Output

The quantity of blood pumped by the heart each minute which is expressed in Liters per Minute (L/min) and is the product of heart rate and stroke volume 

Equation for Cardiac Output

Cardiac Output = Heart Rate × Stroke Volume

Heart Rate (Regulating Factors)

Autonomic Nervous System and Body Temp (minor contributor)

How does the Autonomic Nervous System Contribute to Heart Rate as a regulating factor  in incremental exercise?

Increased parasympathetic (vagal) activity ➡ SA node inhibition — decreased heart rate

Increased Sympathetic Activity ➡ SA nose stimulation — increased heart rate 

Low Body Temp leads to…

decreased HR

High Body temp leads to…

Increased HR

The effects of Vessel Length on blood flow

Increase in length ➡ increase in resistance ➡ decreases in blood flow

• No possible adaptation 

The effects of Blood Viscosity on blood flow

Increase in viscosity ➡ increase in resistance ➡ decreases in blood slow 

• Some possible adaptations

The effects of Vessel Radius on blood flow

Increase in radius ➡ decrease in resistance ➡ increases in blood flow

• Radius exponentially effects flow to the fourth power

What happens if you reduce vessel radius by ½ ?

It diminishes flow to 1/16 the normal amount

Auscultation

1st Atrioventricular (AV) valves close together and 2nd Semilunar Valves close together (the lubdub sound found in the stethoscope) 

What is activated in the left and right when 1st Atrioventricular Valves close together?

Left: Bicuspid (mitral) valve

Right: Tricuspid Valve

What is activated in the left and right when 2nd Semilunar Valves close together?

Left: Aortic Valve

Right: Pulmonic Valve

Cardiac output is maintained in…

prolonged exercise

Equation for Calculating EDV, ESV, and SV

SV = EDV - ESV

SV (Stroke Volume)

Amount of blood ejected from LV per beat

End Diastolic Volume (EDV)

Amount of blood at completion of the filling phase

End Systolic Volume (ESV)

Amount of blood blood left behind after pumping phase

Preload

Reflects End-Diastolic Volume (EDV) and determined by venous return.

During Preload, the more blood filling the left ventricle…

the more stroke volume

High preload…

Higher stroke volume and high pressure in vessels acts as a “wall” blocking stroke volume

High afterload…

Low stroke volume

Low Afterload…

High Stroke Volume

Lower Preload…

Lower stroke volume

Afterload

Reflects Mean Arterial Pressure (MAP) of the Aorta

Gas flows from areas of high pressure to…

areas of low pressure

Sinoatrial Node

SA node depolarizes and sends positive energy to the atriums, then causing the atriums to depolarize and contract sending blood through the bicuspid and tricuspid into the ventricles

Atroventricular Node

AV node depolarizes and sends positive energy along the Bundle of His

Bundle of His

Bundle of His receives depolarization signals and sends positive energy to the right and left bundle branches

Branches

The Branches depolarize and send the positive energy to the Purkinje Fibers within the ventricles

Purkinje Fibers

Purkinje fibers depolarize and cause ventricles to also depolarize and contract sending blood out of the heart via the aorta (to the body) and the pulmonary arteries (to the lungs)

Flow is…

Pressure/Resistance

Redistribution of Blood Flow: Vasodilation

Blood Flow is increased in working skeletal muscles

Redistribution of Blood Flow: Vasoconstriction

Blood flow is reduced to less active organs

Autoregulation

Both self-regulate blood flow based on demand

Heart Rate (HRmax)

0%  improvement

genetic 

Stroke Volume Max (SV Max)

50% improvement. 

Due to increased preload, decreased afterload, and increased ventricular contractility 

Arteriovenous Blood Oxygen Max (a-VO2 max)

50% improvement 

Due to increased muscle blood flow, increased capillary density, and increased number of mitochondria 

What can we expect for people to get increased max oxygen consumption? 

Deconditioned athletes will have a significant increase but elite athletes will not. Training at low levels of intensity will not see much changed but prolonged intensive work will. 

Early Losses results to retraining of VO2 Max

Occurs within days to week and is due to decrease in SV

Later Losses results to retraining of VO2 Max

Occurs within weeks to months due to decreases in the Maximum Aerobic Capacity difference 

Anaerobic Threshold (AT)

The combined lactate (LT) and ventilators (VT) Threshold phenomena.

Intensity at which lactate and or ventilation rise exponentially rather than predictably 

Where is gas exchanged at the Alveolus?

Gas is exchanged at the cellular level

Gas moves from areas of high to low partial pressure. This means that…

Gas move between he lungs, blood, and tissue

High to Low PO₂

Alveolus ➡ lung blood capillary ➡ muscle cell (ABC)

Low to High PO₂

Muscle Cell ➡ lung Capillary blood ➡ alveolus (CBA)

How doe exercise prescriptions differ with respect to Anaerobic thresholds and different populations: General Populations

Neither are better since this is an irrelevant issue to most individuals who are exercising for overall health improvements. Any intensity is fine, the goal is to influence lifestyle factors

How does exercise prescriptions differ with respect to Anaerobic thresholds and different populations: Fitness Populations

AT is most relevant because the goal for fitness/competition is to exercise at the highest intensity possible without causing rapid lactic acid accumulation. 

What percent of CO₂ is converted to bicarbonate in blood?

70%

due to pressure; conversion is temporary and facilitates enhanced transport

What percent of CO₂ is converted to hemoglobin in blood?

20%

What percent of CO₂ is dissolved in the blood?

10%

Diffusion of Gas: Partial Pressure

Total air pressure equals the sum of each individuals pressure (PO₂ and PCO₂)

Diffusion of Gas: Cell Level

Gases diffuse from areas of high to low partial pressure (B/W lung, blood, and tissue) 

Diffusion of gases: PO₂

Air ➡ alveolus ➡ capillary blood ➡ muscle/lung

Diffusion of gases: PCO₂

Muscle/lung ➡ capillary blood ➡ alveolus ➡ air