Buccinator muscle Buccinator muscle The buccinator ( ) is a thin quadrilateral muscle occupying the interval between the maxilla and the mandible at the side of the face. It forms the anterior part of the cheek or the lateral wall of the oral cavity. It arises from the outer surfaces of the alveolar processes of the maxilla and mandible, corresponding to the three pairs of molar teeth; and behind, from the anterior border of the pterygomandibular raphé which separates it from the constrictor pharyngis superior. It is attached upon the buccinator crest as far forward as the first molar tooth. The fibers
Psoas major muscle L3 nerves. In less than 50 percent of human subjects, the psoas major is accompanied by the psoas minor. In mice, it is mostly a fast-twitching, type II muscle, while in human it combines slow and fast-twitching fibers. This muscle is equivalent to the tenderloin. The psoas major joins the upper body and the lower body, the axial to the appendicular skeleton, the inside to the outside, and the back to the front. As part of the iliopsoas, psoas major contributes to flexion in the hip joint. On the lumbar spine, unilateral contraction bends the trunk laterally, while bilateral contraction