Slow-twitch muscle fiber characteristics

Finally, slow-twitch muscle fibers have a small diameter. This facilitates the diffusion of oxygen through the fiber to the mitochondria where it is utilized. Taken together, each of these characteristics enhances the ability of these fibers to utilize oxygen. Therefore, in slow-twitch oxidative muscle... 

Mammalian skeletal muscle can be separated Into two distinct fiber populations, based on relative contraction characteristics, and are referred to as slow-twltch (Type I) or fast-twitch (Type II) fibers. The slow-twltch fiber type exhibits a relatively low shortening velocity (27), a low rate of tension development (27). a low myosin ATPase activity (28) and a low rate of calcium sequestration by the sarcoplasmic reticulum (29). The converse Is true for the fast-twitch fibers. Since contraction velocity highly correlates with myosin ATPase activity (30), It Is possible to easily Identify,... 

---