Question

The answer is D. Muscle B is characteristic of a slow twitch muscle (Type 1) composed of predominantly slow twitch muscle fibers. These fibers are smaller in size and are innervated by smaller nerve fibers. They typically have a more extensive blood supply, a greater number of mitochondria, and large amounts of myoglobin, all of which support high levels of oxidative phosphorylation. What is the characteristic of Muscle B?

1) Type 1 muscle
2) Fast twitch muscle
3) Large muscle fibers
4) Slow twitch muscle

Answer 1

Muscle B is characterized as a Type 1 slow twitch muscle fiber, which is smaller in diameter, rich in capillaries, mitochondria, and myoglobin, allowing for high endurance and resistance to fatigue during aerobic activities.

Step-by-step explanation:

The characteristic of Muscle B that is being asked about pertains to its type and physiological properties. Muscle B is characteristic of a slow twitch muscle, also known as Type 1 muscle fibers. These muscle fibers are known for their high endurance capabilities and are ideal for prolonged aerobic activities, such as distance running or cycling. They contain a high number of mitochondria, are dense with capillaries, and contain myoglobin, which allows them to sustain aerobic activities by efficiently using oxygen to generate ATP. In comparison to fast twitch muscle fibers, Type 1 fibers have smaller diameters and are innervated by smaller nerve fibers. As a result, they produce less force but are more resistant to fatigue.