Cardiovascular System
What is the Fick equation?
oxygen consumption to cardiac output
Three determinants of endurance exercise performance?
VO2 Max, Lactate Threshold, and Exercise Economy.
What are the conducting and respiratory zones of the lungs?
A: Conducting Zone: Air passage (no gas exchange).
Respiratory Zone: Gas exchange site (alveoli).
How does endurance training affect VO2 Max
Increases cardiac output (stroke volume).
Improves a-vO2 difference (muscle oxygen extraction).
What muscle type has the most myoglobin and mitochondria?
A: Slow-twitch (Type I) fibers
What is Cardiac Output
Heart rate x Stroke volume.
What type of athlete would have the highest VO2 Max
Cross-country skiers, distance runners, and cyclists.
What structures interface at the blood-gas barrier?
Alveolar wall and capillary wall.
How does the heart adapt to endurance training?
How does the heart adapt to endurance training?
A: Increased stroke volume.
Larger left ventricle.
Lower resting heart rate.
How do muscles override sympathetic vasoconstriction during exercise?
Local metabolites (e.g., CO2, nitric oxide) cause vasodilation, overriding sympathetic signals.
Describe blood flow through the cardiovascular system
A: Pulmonary Circuit: Right atrium -> Right ventricle -> Pulmonary arteries -> Lungs -> Pulmonary
veins -> Left atrium.
Systemic Circuit: Left ventricle -> Aorta -> Arteries -> Capillaries -> Veins -> Vena cava -> Right
atrium.
Is VO2 Max the best predictor of endurance performance?
No, Lactate Threshold and Exercise Economy are better predictors in well-trained athletes.
How is oxygen carried in the blood?
A: Bound to hemoglobin (~98%).
Dissolved in plasma (~2%).
How does the cardiovascular system respond to graded exercise?
A: VO2: Increases with intensity.
Cardiac Output: Increases to deliver more oxygen.
Stroke Volume: Increases initially, then plateaus.
a-vO2 Difference: Increases with oxygen extraction by muscles.
What is the difference between myoglobin and hemoglobin?
A: Myoglobin: Stores oxygen in muscle fibers.
Hemoglobin: Transports oxygen in blood.
What are the five types of blood vessels and their functions?
A: Arteries: Carry oxygenated blood under high pressure.
Arterioles: Regulate blood flow into capillaries.
Capillaries: Site of gas and nutrient exchange.
Venules: Collect deoxygenated blood.
Veins: Return deoxygenated blood to the heart.
What are the conducting and respiratory zones of the lungs?
A: Conducting Zone: Air passage (no gas exchange).
Respiratory Zone: Gas exchange site (alveoli)
What is the ventilatory threshold?
The point where ventilation rises disproportionately to oxygen consumption due to CO2 from
lactate buffering.
How does the blood adapt to endurance training?
A: Increased blood volume.
More red blood cells and hemoglobin.
What are the five steps of gas transport?
A: Ventilation -> Diffusion (lungs) -> Circulation -> Diffusion (tissues) -> Utilization.
Describe the neural conduction system of the heart.
SA Node -> AV Node -> Bundle of His -> Bundle Branches -> Purkinje Fibers.
BONUS:
What are baroreceptors, and what do they control?
Pressure sensors in arteries (e.g., carotid sinus, aortic arch) that regulate blood pressure.
Describe the PO2 gradient in the cardiorespiratory system.
Oxygen moves down its partial pressure gradient from alveoli -> blood -> tissues.
What structural changes occur in the heart after strength training?
Thickened ventricular walls to handle high blood pressure.
BONUS
What is the role of genetics in aerobic fitness?
Genetics influence baseline VO2 Max and adaptability to training.