Foundational Scientific Disciplines Flashcards

Which muscle fiber type relies predominantly on oxidative phosphorylation for ATP production during prolonged endurance exercise?

Answer: Type I fibers

Type I (slow-twitch) fibers have high mitochondrial density and rely primarily on oxidative phosphorylation, making them fatigue-resistant during endurance exercise.

In biomechanics, the moment of inertia describes an object's resistance to:

Answer: Rotational acceleration

Moment of inertia quantifies how difficult it is to change an object's rotational motion, analogous to mass in linear mechanics.

Which neurotransmitter is primarily responsible for excitation at the neuromuscular junction?

Answer: Acetylcholine

Acetylcholine is released by motor neurons at the neuromuscular junction, binding nicotinic receptors to trigger muscle fiber depolarization.

The Fick equation for maximal oxygen uptake (VO2max) is best expressed as:

Answer: VO2max = HR × SV × (CaO2 − CvO2)

The Fick equation states VO2 = cardiac output × arteriovenous oxygen difference (CaO2 − CvO2), where HR × SV equals cardiac output.

Which statistical measure is most appropriate for describing the central tendency of a highly skewed distribution of recovery times?

Answer: Median

The median is resistant to extreme values and better represents central tendency when data are skewed, unlike the mean which is pulled toward outliers.

During high-intensity exercise, the primary buffer system combating lactic acid accumulation in the blood is:

Answer: Bicarbonate buffer system

The bicarbonate buffer system (H⁺ + HCO₃⁻ → H₂CO₃ → H₂O + CO₂) is the most important extracellular buffer for metabolic acids during intense exercise.

In research methodology, internal validity is most threatened by which of the following?

Answer: Pre-test sensitization confounding results

Pre-test sensitization (testing effects) is a classic threat to internal validity because exposure to initial measurement can alter participants' responses to the intervention.