[Plate 55, Muscles Involved in Mastication (Continued)]
Muscle Origin Insertion Innervation Blood Supply Main Actions
GenioglossusMental spine of
mandible
Dorsum of
tongue and
hyoid bone
Hypoglossal
nerve
Sublingual and submental arteries Depresses and
protrudes tongue
Hyoglossus Body and greater
horn of hyoid
bone
Lateral and
inferior aspect
of tongue
Hypoglossal
nerve
Sublingual and submental arteries Depresses and
retracts tongue
Styloglossus Styloid process
and stylohyoid
ligament
Lateral and
inferior aspect
of tongue
Hypoglossal
nerve
Sublingual artery Retracts tongue and
draws it up for
swallowing
PalatoglossusPalatine
aponeurosis of
soft palate
Lateral aspect
of tongue
Vagus nerve
and pharyngeal
plexus
Ascending pharyngeal arteries and
Palatine branches of facial and
maxillary arteries
Elevates posterior
tongue
Palate
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Forms roof of mouth and floor of nasal cavities
Consists of two parts
Hard palate anteriorly
Formed from by palatine processes of maxillae and horizontal plates of palatine bones
Covered with periosteum and oral mucosa (inferiorly) and respiratory mucosa superiorly
Has five foramina
a. Incisive fossa behind central incisors transmits nasopalatine nerves via incisive canals
b. Paired greater palatine foramina medial to third molar transmits greater palatine vessels and nerves
c. Paired lesser palatine foramina posterior to greater palatine foramina transmits lesser palatine nerves and vessels
Mucous secreting palatine glands beneath mucosa
Incisive papilla directly posterior to maxillary incisors
Palatine raphe
a. Midline ridge/groove