Muscles 2 Flashcards
4 Paired Muscles of Mastication
Masseter, Temporalis, Medial pterygoid, Lateral pterygoid (innervate: Trigeminal!)
Mastication Muscles: action
depression, elevation, protrusion, retraction, lateral deviation
Masseter Muscle
Strongest. anterior to parotid; *elevates mandible to close mouth
Masseter Pathology
bruxism, hypertrophy
Temporalis Muscle
fan-like attachment filling temporal fossae; * entire muscle elevates mandible to close mouth, posterior part of muscle contracting retracts the mandible
Medial Pterygoid
internal. runs up and down, deep head + superficial head- both insert at ramus + angle; *elevates/closes mandible
Medial Pterygoid: Deep Head origin
lateral pterygoid plate of sphenoid bone
Medial Pterygoid: Superficial Head origin
process of palatine bone + maxillary tuberosity
Lateral Pterygoid
external. infratemporal fossae; *depresses mandible, opens jaw (only muscle responsible for this!) *when both muscles contract = protrusion, when 1 side contracts = lateral deviation)
Lateral Pterygoid: Superior Head
greater sphenoid wing > TMJ
Lateral Pterygoid: Inferior Head
lateral pterygoid plate of sphenoid > anterior condyle of mandible
Hyoid Muscles: Supra
Digastric, Mylohyoid, Stylohyoid, Geniohyoid
Hyoid Muscles: Infra
Sternothyroid, Sternohyoid, Omohyoid, Thryrohyoid
Digastric Muscle
[supra] two bellies: anterior/posterior (makes an āLā) *pulls back jaw
Mylohyoid Muscle
[supra] lateral. *forms floor of mouth, elevates tongue and hyoid bone