Myology (MYOLOGIA) - the science of muscles
- Category: Musculoskeletal system
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Development of the muscles
The muscles and fascia develop from myotomes, including from the dorsal part of myotomes develop deep back muscles, from the ventral part of myotomes - the muscles of the front and literal surface of the body (muscles of the chest, abdomen, neck). The diaphragm develops from the sixth cervical myotome. At the end of 4-th week of fetal development, muscles of limbs develop from buds of limbs. From buds of mesoderm the anterior of 4 lower cervical and first thoracic myotomes develop muscles of the upper limbs. Chewing and mimic muscles, some muscles of the neck, the muscles of the soft palate, throat, larynx develop from the mesoderm of gill arches.
According to development the muscles are classified on:
- the muscles that in development remain at the site;
- the muscles that move from the trunk to the extremities;
- the muscles that move from extremities to the trunk.
The structure of the muscles
Muscle consists of the fleshy part formed by bundles of muscle fibers and tendon. Wide tendon is called aponeurosis. In some muscle the bundles of muscle fibers are interrupted by short tendon divisions. Muscle fibers are covered with a connective tissue membrane - endomysium. Bundles of muscle fibers are covered by perimysium. Muscle is covered with epimysium, which is located in the region of tendon and is called peritendineum. With the reduction of muscle one end of its is fixed - fixed point. This point coincides with the beginning of muscle. The other end of the muscle changes its position while reducing - movable (mobile) point. This point coincides with the location of attachment of muscles.
Features of the muscles
With the reduction of muscles are performed movements in bone joints. The muscles that perform opposite movements in the joint, are called antagonists. The muscles that perform the same movement in the joint, called synergists.