PATHOLOGY

Detailed explanation-1: -Most of the muscles in your body have more than one kind of muscle fiber. But some muscles have more slow-twitch fibers because they have to do the same job for a long time. For example, the muscles in the back of your lower legs and the muscles in your back are mostly made up of slow-twitch fibers.

Detailed explanation-2: -The two types of skeletal muscle fibers are slow-twitch (type I) and fast-twitch (type II). Slow-twitch muscle fibers support long distance endurance activities like marathon running, while fast-twitch muscle fibers support quick, powerful movements such as sprinting or weightlifting.

Detailed explanation-3: -In humans, type I, or slow-twitch, fibers possess slower twitch speeds and are relatively fatigue resistant. Type IIa fibers, or fast oxidative glycolytic (FOG) fibers, present higher twitch speeds than type I fibers but are less fatigue resistant.

Detailed explanation-4: -(a) The muscle type that is slow to contract is smooth muscle. It is known to produce slow contractions because the smooth muscle has calcium channels which open much more slowly that other muscles.