Digastric muscle side; anterior belly may be absent and posterior belly inserted into the middle of the jaw or hyoid bone. The tendon may pass in front, more rarely behind the Stylohoideus. The Mentohyoideus muscle passes from the body of hyoid bone to chin. The Digastricus divides the anterior triangle of the neck into three smaller triangles. The digastric muscle is involved in any complex jaw action such as speaking, swallowing, chewing and breathing. When the digastric muscle contracts, it acts to elevate the hyoid bone. If the hyoid is being held in place (by the infrahyoid muscles), it will tend to
Aponeurosis of the abdominal external oblique muscle Aponeurosis of the abdominal external oblique muscle The aponeurosis of the abdominal external oblique muscle is a thin but strong membranous structure, the fibers of which are directed downward and medially. It is joined with that of the opposite muscle along the middle line, and covers the whole of the front of the abdomen; above, it is covered by and gives origin to the lower fibers of the pectoralis major; below, its fibers are closely aggregated together, and extend obliquely across from the anterior superior iliac spine to the pubic tubercle and the pectineal line. In the middle line, it