Essay On Muscle Contraction

Classify muscles and factors affecting muscle tension

Classification of muscle tissue

Muscle tissue can be classified into three different types, skeletal muscle, cardiac muscle and smooth muscle.

1) Skeletal muscle tissue

Skeletal muscle fibers are multinucleate cells and the longest muscle cells and have obvious stripes called striations. It also known as voluntary muscle because it can be control consciously. Skeletal muscle is responsible for overall body mobility. Skeletal muscle fibers can be classified into type 1 fibers, type II(a) fibers and type II(b) fibers.

Type 1 fiber (slow oxidative fiber)

It contract relatively slow because its myosin ATPases are slow. It depends on oxygen delivery and aerobic pathways and is fatigue resistant

It is mononucleate cells and striated but it cannot be control voluntarily. It is stimulated by nervous system.

3) Smooth muscle tissue can be found in visceral organs such as urinary bladder, stomach and airway passage. It cannot be control voluntarily and depends on autonomic nervous system. Muscle cells are elongated fibers but with no striation. Contractions of the muscle are slow and sustained.

Factors affecting muscle tension

1) Number of muscle fibers stimulated and the size of the fibers

Motor unit is the fundamental of muscle contraction. The more motor unit are recruited, the greater the muscle force. The greater the cross sectional area or diameter, the more tension it can develop and the greater its strength.

2) Frequency of muscle stimulation

As a muscle begins to contract, internal tension generated by the cross bridges stretches the connective tissue sheath. When it became taut, it will transfer the tension to the muscle insertion called as external tension. In normal contraction, external tension is less than internal tension. When a muscle is stimulated rapidly, the contractions are summed becoming stronger and more vigorous. Therefore, the greater the force it will