Comprehensive Final Energy system and muscle fibers Flashcards
(23 cards)
What does the Immediate Energy System rely on for energy production?
ATP and creatine phosphate stored in the muscle fiber
How long can the Immediate Energy System sustain high-intensity exercise?
10 seconds
What type of exercise relies on the Lactic Acid Energy System?
Short-duration, high-intensity exercise lasting 2 to 4 minutes
What is the primary nutrient used in the Lactic Acid Energy System?
Carbohydrate (glucose)
How does skeletal muscle obtain glucose for the Lactic Acid Energy System?
from blood glucose or breaking down muscle glycogen
What type of exercise utilizes the Oxidative Energy System?
Lower intensity, sustained exercise
Which macronutrients are used in the Oxidative Energy System?
Carbs and fatty acids (mainly fatty acids)
How long does it take for the Oxidative Energy System to become dominant during exercise?
Within 5 minutes of sustained activity. And it can be done theoretically
What is the sarcomere, and what does it contain?
It is the contractile unit of muscle fibers and contains myosin and actin proteins.
What enzyme provides energy for muscle contraction?
Myosin ATPase.
What forms a motor unit?
Several muscle fibers innervated by a single α-motor neuron.
What is the myoglobin content in Type I muscle fibers?
High
What is the myoglobin content in Type IIa muscle fibers?
Moderate to high
What is the myoglobin content in Type IIb muscle fibers?
Low
What is myoglobin & what is the function?
a protein found in muscle cells that binds to oxygen/ facilitates oxygen storage and transport within muscle cells, ensuring a steady supply for energy production during muscle contraction.
Where is myoglobin most abundant?
in muscle fibers with high aerobic capacity, such as Type I and Type IIa fibers
Why is myoglobin important for endurance activities?
It enhances the muscle’s ability to sustain prolonged exercise by improving oxygen availability for aerobic metabolism.
What is the primary function, contraction speed, & metabolic rate of Type I muscle fibers?
They support sub-maximal, longer-duration muscular contraction, Slow, & High aerobic/oxidative capacity
Why are Type I fibers resistant to fatigue?
Due to their abundant mitochondria and oxidative enzymes.
What is the primary function, contraction speed, & metabolic rate of Type IIa muscle fibers?
balance high-force activities/endurance, faster contraction speed compared to Type I, Intermediate metabolic rate with both aerobic and anaerobic capacities
Why are Type IIa fibers referred to as fast oxidative glycolytic (FOG) fibers?
they use both oxidative and glycolytic pathways for ATP production
What is the primary function, contraction speed, & metabolic rate of Type IIb muscle fibers?
They are suited for high-intensity, high-force, rapidly contracting activities, The fastest contraction speed, & High anaerobic metabolic rate with poor aerobic capacity
Why do Type IIb fibers fatigue quickly?
Due to relying anaerobic pathways and lower oxidative enzyme content.
