What Is a Myofiber?

Muscle fibers are muscle cells, which are called muscle fibers because they are thin and long. Muscle fibers are divided into red muscle fibers and white muscle fibers, which have different names of red and white because of their different appearances. Red muscle fibers are also called type I fibers, slow contraction fibers, and slow oxidized fibers; white muscle fibers are also known as type II fibers, fast-shrinking muscle fibers, or fast-dissolving sugar fibers.

Muscle fiber

Muscle fibers are muscle cells, which are called muscle fibers because they are thin and long. Muscle fibers are divided into red muscle fibers and white muscle fibers, which have different names of red and white because of their different appearances. Red muscle fibers are also called type I fibers, slow contraction fibers, and slow oxidized fibers;

Red muscle fiber and white muscle fiber

Even the ratio of different parts in the same muscle may not be the same. Naturally, the ratio of different positions in the same person will not be the same, and the difference in the fiber of the same muscle in different people is even more obvious. The ratio of fast-twitch muscle fibers in different parts of the body is also different.

Muscle fibers under the microscope

Muscles are composed of fast muscle fibers and slow muscle fibers. Two types of muscle fibers play different roles in exercise.

Slow muscle fibers are inferior to fast muscle fibers in strength and explosive power, but they have good endurance. Because it contains oxygen, mitochondria, and myoglobin (a pigment that transports oxygen in muscle cells), it is a binding protein similar to a subunit of hemoglobin. The oxygen released by the red blood cells combines to store oxygen and transport it to the mitochondria of the muscle cells, where oxygen oxidizes glucose to produce carbon dioxide and water. Birds are mainly composed of slow muscle fibers, so they can fly for long periods of time.