Physical and anatomical characteristics of the masticatory muscles in camels (Camelus dromedarius)

The current study aims to understand the dynamics of the masticatory muscles during closure and opening actions and assess the functional architecture of the various chewing muscles in camels. Twelve healthy adult camel heads of different sexes and ages (2-3 years) from the typical slaughterhouses in Iraq and the Kingdom of Saudi Arabia. A comparative anatomical examination and masticatory muscle linear measurements were performed on the head of the slaughtered camel. These included the masseter, temporalis, pterygoideus, and digastricus muscles. This study included recording the values of each fiber length, weight of the muscle, the mass of muscle, volume of muscle, density, Physiological cross-sectional area (PCSA), force, maximum isometric force, torque, and kinetic energy of the masticatory muscles. According to this study, the masseter and temporalis muscles closed the camel's jaw, while the digastricus and pterygoideus muscles opened the mandible. This study showed that the group of muscles that closed the jaw had greater PCSA values, maximum isometric force, force, torque, and kinetic energy than those that opened the mandible. It is believed that jaw closure is regarded as the muscles' heightened activity that closes the jaw. This study proved that each muscle has its own physical characteristics that differ from others.