肌肉结构（Muscle structure）.docVIP

肌肉结构（Muscle structure） Knowledge of muscle structure First, muscle tissue, muscle tissue, muscle cells are thin filamentous, known as muscle fiber, its characteristic is to change the chemical energy to mechanical energy, so that muscle fibers shrink, tightening, in order to guarantee the activities of the body. Muscle tissue can be divided into smooth muscle, skeletal muscle and heart muscle according to its shape and utility. Layout characteristics: muscle cells are long cylindrical or spindle shaped, usually referred to as muscle fiber, muscle cells are closely divided, and there are a small number of connective tissue, capillaries and nerve fibers between the cells. When the muscle damage, can cause bleeding and nerve damage The classification of muscle tissue is as follows: Skeletal muscle (spread out on bones) Myocardial tissue (diffuse in the heart) Smooth muscle (diffuse in the viscera and blood vessel wall) The distribution of muscle in human body is very common, and there are about 500 pieces of muscle in the whole body. Its weight is about 40% of the body weight, and the muscle of the limbs accounts for about 80% of the total weight of the muscle. The basic characteristics of muscle tissue are contraction and release. Contraction of muscle contraction, cross section increased, when relaxed, the same. Because the central nervous system constantly excited, so that the muscles often retain the constant state of delicate contraction, this state is called muscle urgency, muscle emergency can make the body maintain a certain position. In fact, when people are stable, the muscles are still in a slightly tight state. Each muscle is composed of many muscle fibers gathered together in a bundle, and then by a lot of small bundles merge into a large number of bundles, and finally by the large bundles merge into the muscle as a whole. The outer part of the whole muscle is wrapped in connective tissue membrane, called the muscle coat, and it is called the tendon as the