DIFFERENT TYPES OF SKELETAL MUSCLES::
Most skeletal muscles are composed of a mixture of three types of muscle fibers:(1) Fast twitch glycolytic A (2) Slow twitch B and (3) Fast twitch oxidative C
Fast twitch glycolytic A fibers predominate on the surface of the body they are pale in color (white) because of a low myoglobin content and blood capillaries they derive their energy from aerobic pathways these fibres generate forces of high intensity for short durations such as those produced during weight lifting they contract and fatigue rapidly the number of mitochondria present are less these fibers are also known as fast white fibres
Fast twitch oxidative C fibers are found in muscles which are deep within body they contain high amount of myoglobin and hence appear to be red coloured they are also known as fast red fibres these fibers derive the energy from aerobic pathways of metabolism the rate of contraction of these fibres is fast but rate of fatigue moderate these cells are involved in activities which demand the kind of endurance for swimming and long distance running
Slow twitch B fibers are found in the muscles of posture long muscles of back etc they are also rich in myoglobin and hence dark red colored and derive their energy through aerobic pathways they have slowest rate of contraction and fatigue these fibres have more blood capillaries and more mitochondria
0 Comments