Muscles of Mastication

Question 1

structure of the mandible

Answer 1

site for muscle attachments
body, angle, ramus, condylar process, coronoid process

Question 2

temporomandibular joint

Answer 2

mandibular fossa of temporal bone and condylar process of mandible
modified hinge synovial joint, FIBROCARTILAGE on articular surface
articular disc separates disc into superior/inferior cavities

sphenomandibular, stylomandibular and lateral ligament

Question 3

movements of TMJ

Answer 3

protrusion -> lateral / medial pterygoid
retraction -> temporalis, geniohyoid, masseter
elevation -> temporalis, masseter, medial pterygoid
depression -> gravity, digastric, mylohyoid, lateral pterygoid
lateral side-to-side -> lateral and medial pterygoid [grinding/chewing]

Question 4

name the MoM and nerve supply

Answer 4

temporalis, masseter, medial pterygoid, lateral pterygoid

all by mandibular division of trigeminal CNV3

Question 5

temporalis

Answer 5

location = temporal fossa, coronoud process of mandible, anterior border of ramus of mandible near last molar, fan shape
action = retracts and elevates mandible [closing mouth]
innervation = CNV3

Question 6

masseter

Answer 6

location = maxillary process of zygomatic bone, angle and lateral surface of mandible
action = elevates mandible
innervation = CNV3

Question 7

medial pterygoid

Answer 7

location = medial surface of ramus and angle of mandible
- traverses diagonally near eye way
actions = elevates mandible, lateral side to side
innervation = CNV3

Question 8

lateral pterygoid

Answer 8

location = infratemporal of sphenoid bone, pterygoid plate
- near ear, runs straight

action = PROTRUSION of mandible, lateral side to side, depression of mandible

innervation = CNV3

Question 9

CN V3 nerve supply types

Answer 9

sensory
motor for muscles of mastication
- also supplues tensor tympani in ear, tensor palati, mylohyoid, anterior belly of digastric [nerve to mylohyoid]

Question 10

elevation of mandible by

Answer 10

temporalis, masseter, medial pterygoid

Question 12

depression of the mandible is done by

Answer 12

lateral pterygoid, suprahyoud and infrahyoid

Question 13

protrusion of the mandible is done by

Answer 13

lateral pterygoid, masseter and medial pterygoid

Question 14

retrusion of the mandible is done by

Answer 14

temporalis

Question 15

lateral side to side movements of the mandible is done by

Answer 15

temporalis of same side, pterygoid of opposite side, masseter

Question 16

phases of swallowing are

Answer 16

oral [voluntary]
pharyngeal [involuntary]
oesophageal

Question 17

oral swallowing phase

Answer 17

voluntary
food bolus coordinated by tongue, pushed to oropharynx, soft palate closes to nasopharynx

Question 18

pharyngeal swallowing phase

Answer 18

superior pharyngeal contraction and soft palate elevation
pharyngeal elevation to recieve food bolus, oesophagus by constrinctors
epiglottis closes the laryngeal inlet
elevation of pharynx and larynx, hyoid
respiration temporarily

Question 19

oesophageal swallowing phase

Answer 19

inferior pharyngeal constrictor contracts, upper relaxes, food bolus moves down to oesophagus
peristatic movements to stomach

Question 20

infratemporal fossa

Answer 20

Base of the skull, deep to the masseter
conduit for neurovascular structures entering/exiting cranial cavity

Question 21

structures in the infratemporal fossa

Answer 21

muscles - lateral pterygoid
arteries - maxillary, IA, long buccal
nerves - IA, lingual, long buccal, chorda tympani, otic ganglion

Question 22

chorda tympani

Answer 22

branch of facial nerve
joins lingual nerve to innervate anterior 2/3 tongue taste special sensory

Question 23

auriculotemporal nerve

Answer 23

CN V3
leaves foramen ovale, travels up
encircles MMA
sensory to auricle, temporal, TMJ
secretomotor fibres to parotid gland from otic ganglion
motor

Question 24

inferior alveolar nerve

Answer 24

CN V3
enters mandibular foramen
supplies mandibular teeth
branches to mental nerve through foramen
supplies skin of lower lip/chin, gingiva of mandibular incisors

Question 25

lingual nerve

Answer 25

CN V3
joined by chorda tympani in infratemporal fossa
sensory taste to anterior 2/3 tongue, lingual gingivae
medial and inferior to 2nd molar

Question 26

maxillary artery comes from

Answer 26

ECA - terminal branch
in infratemporal fossa

Question 27

3 main branches of maxillary artery

Answer 27

mandibular, pterygoid and pterygopalatine

Question 28

mandibular branch of maxillary artery

Answer 28

middle meningeal artery [pterion, facial nerve]
inferior alveolar artery [mandible, teeth, mylohyoid, chine]

Question 29

pterygoid branch of maxillary artery

Answer 29

masseteric [masseter, TMJ]
deep temporal [temporalis]
buccal [buccinator]

Question 30

pterygopalatine branch of maxillary artery

Answer 30

superior alveolar [maxillary teeth, mucosa]
infra-orbital [maxillary incisors, around eye]
descending palatine [greater and lesser palatine, hard/soft palate]