mastication

Lateral Pterygoid

Lateral Pterygoid The structure indicated is the lateral pterygoid muscle. The lateral pterygoid muscle is one of four muscles of mastication: Masseter Temporalis Medial pterygoid Lateral pterygoid The muscles of mastication act on the temporomandibular joint (TMJ), which is the joint of the jaw formed between the mandible and temporal bone. The TMJ is a synovial joint, which differs in structure to other synovial joints in that it contains a fibrocartilagenous articular disc that divides the joint into two parts. The two joint compartments result in different movements at the TMJ. The lower joint compartment allows rotational movement, whilst the …

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lateral pterygoid

Temporalis Muscle

Temporalis Muscle The structure indicated is the temporalis muscle. This muscle is one of the muscles of mastication. The muscles of mastication include: Masseter Temporalis Medial pterygoid Lateral pterygoid The temporalis muscle is a large fan-shaped muscle which lies in the temporal fossa above the zygomatic arch. Origin: temporal line of parietal bone. Temporal surface of sphenoid bone Insertion: coronoid process of mandible and ramus of mandible Innervation: mandibular branch of trigeminal nerve (cranial nerve V) Action: Elevation of the mandible and retraction of the mandible (via posterior horizontal fibres) To learn more about the muscles of mastication, check out …

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temporalis

Masseter

Masseter The muscle highlighted is the masseter. This muscle is one of the muscles of mastication. The muscles of mastication include: Masseter Temporalis Medial pterygoid Lateral pterygoid The masseter is rectangular in shape and consists of a superficial part and a deep part. Origin: zygomatic arch and maxillary process of the zygomatic bone Insertion: lateral surface of ramus of mandible Innervation: masseteric nerve – a branch of the mandibular nerve (V3) Blood supply: masseteric artery To learn more about the muscles of mastication, check out this tutorial!

Masseter