PTC Exercise Physiology and Anatomy 1 — Questions and Answers
Question 1: Which muscle is primarily responsible for knee extension?
- Hamstrings
- Quadriceps (Correct answer)
- Gastrocnemius
- Hip flexors
Correct answer: Quadriceps
The quadriceps femoris group, located on the anterior thigh, is the primary muscle responsible for extending the knee joint.
Question 2: What is the term for the period when the heart ventricles are contracting and pumping blood?
- Diastole
- Systole (Correct answer)
- Cardiac cycle
- Stroke volume
Correct answer: Systole
Systole refers to the phase of the cardiac cycle when the ventricles contract and eject blood into the arteries.
Question 3: Which energy system provides the majority of ATP during a 400-meter sprint?
- Phosphagen system
- Glycolytic system (Correct answer)
- Oxidative system
- ATP-CP system
Correct answer: Glycolytic system
The glycolytic (anaerobic glycolysis) system predominates during moderate-to-high intensity activities lasting 30 seconds to 2 minutes, such as a 400-meter sprint.
Question 4: What is VO2 max?
- Maximum heart rate during exercise
- Maximum volume of oxygen the body can use per minute (Correct answer)
- Resting oxygen consumption
- Oxygen debt after exercise
Correct answer: Maximum volume of oxygen the body can use per minute
VO2 max is the maximum rate at which an individual can consume oxygen during intense exercise, expressed in mL/kg/min, and is the gold standard measure of aerobic capacity.
Question 5: Which type of muscle fiber is best suited for endurance activities?
- Type IIb fast-twitch
- Type IIa fast-twitch oxidative
- Type I slow-twitch (Correct answer)
- Type IIx fast-twitch
Correct answer: Type I slow-twitch
Type I (slow-twitch) muscle fibers have high mitochondrial density and aerobic capacity, making them highly resistant to fatigue and ideal for sustained endurance activities.
Question 6: What happens to stroke volume during aerobic exercise at moderate intensity?
- It decreases
- It remains unchanged
- It increases (Correct answer)
- It becomes irregular
Correct answer: It increases
Stroke volume increases during moderate aerobic exercise due to greater venous return, increased myocardial contractility, and the Frank-Starling mechanism.
PTC Exercise Physiology and Anatomy 1
Which muscle is primarily responsible for knee extension?