Mastication

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Introduction

Mastication is the process whereby food is broken down by mechanical digestion in the oral cavity. The cheeks and tongue function to position food over the teeth where grinding can occur.

Rumination allows food to undergo mastication more than once. Also called 'chewing the cud', it allows greater nutrients to be extracted and absorbed from the food particles.

Mastication requires correct muscle movements and jaw articulation.

Muscles of Mastication

The muscles of mastication are well developed.

Jaw Opening Muscles

• Digastricus muscle

   -Origin: paracondylar process of occipital bone
   -Insertion: angle of mandible
   -Two bellies: caudal half from the second visceral arch innervated by facial nerve (CV VII)
                 cranial half from the first visceral arch innervated by the mandibular branch of the trigeminal (CV V3)
   -Herbiverous species have a limited digastricus muscle
   -Canids have a larger digasticus muscle (but smaller in comparison with jaw closing muscles)

Jaw Closing Muscles