Anatomical terms of muscle Anatomical terms of muscle Muscles are described using unique anatomical terminology according to their actions and structure. There are three types of muscle tissue in the human body: skeletal, smooth, and cardiac. Skeletal striated muscle, or "voluntary muscle", primarily joins to bone with tendons. Skeletal muscle enables movement of the bones of the human skeleton and maintains posture. Smooth muscle tissue is found in parts of the body where it conveys action without conscious intent. The majority of this type of muscle tissue is found in the digestive and urinary systems where it acts by propelling forward food, chyme, and
Muscle network which could show a large degree of divergence in the formation of muscle cells. Through this analysis, it seems that the myogenic GRN is an ancestral GRN with actual changes in myogenic function and structure possibly being linked to later coopts of genes at different times and places. Evolutionarily, specialized forms of skeletal and cardiac muscles predated the divergence of the vertebrate/arthropod evolutionary line. This indicates that these types of muscle developed in a common ancestor sometime before 700 million years ago (mya). Vertebrate smooth muscle was found to have evolved independently from the skeletal and cardiac muscle types.