Week 19 - Infratemporal Fossa & Muscles of Mastication

Question 1

What does the temporal region of the head include?

Answer 1

• Lateral area of the scalp
• Deeper soft tissues overlying the temporal fossa

Superior to the zygomatic arch

Question 2

What primarily occupies the temporal fossa?

Answer 2

Upper portion of the temporalis muscle

Question 3

What are the boundaries of the temporal fossa?

Answer 3

• Posteriorly and superiorly: Temporal lines
• Anteriorly: Frontal and Zygomatic bones
• Laterally: Zygomatic arch
• Inferiorly: Infratemporal crest

Question 4

Which bones form the floor of the temporal fossa?

Answer 4

• Frontal
• Parietal
• Temporal
• Greater wing of the sphenoid

Question 5

What does the temporal fascia cover?

Answer 5

Temporalis muscle, attaching superiorly to the superior temporal line

Question 6

What structure provides resistance when the masseter muscle contracts?

Answer 6

Temporal fascia

Question 7

Where is the infratemporal fossa located?

Answer 7

• Deep and inferior to the zygomatic arch
• Deep to the ramus of the mandible
• Posterior to the maxilla

Question 8

What are the boundaries of the infratemporal fossa?

Answer 8

• Laterally: ramus of the mandible
• Medially: lateral pterygoid plate
• Anteriorly: posterior aspect of the maxilla
• Posteriorly: tympanic plate and mastoid and styloid processes of the temporal bone
• Superiorly: inferior surface of the greater wing of the sphenoid
• Inferiorly: medial pterygoid muscle attachment

Question 9

What structures are contained within the infratemporal fossa?

Answer 9

• Inferior part of the temporalis muscle
• Lateral and medial pterygoid muscles
• Maxillary artery
• Pterygoid venous plexus
• Mandibular, inferior alveolar, lingual, buccal, and chorda tympani nerves
• Otic ganglion

Question 10

What type of joint is the temporomandibular joint (TMJ)?

Answer 10

Modified hinge type of synovial joint

Question 11

What movements are permitted by the TMJ?

Answer 11

• Gliding (translation)
• Small degree of rotation (pivoting)
• Flexion (elevation)
• Extension (depression)

Question 12

What are the bony articular surfaces involved in the TMJ?

Answer 12

• Mandibular fossa of the temporal bone
• Articular tubercle of the temporal bone
• Head of the mandible

Question 13

What separates the two bony articular surfaces in the TMJ?

Answer 13

Intervening fibrocartilage, the articular disc of the TMJ

Question 14

What is the function of the intrinsic lateral ligament of the TMJ?

Answer 14

Strengthens the joint laterally and prevents posterior dislocation

Question 15

What is the primary passive support of the mandible?

Answer 15

Sphenomandibular ligament

Question 16

Which muscles elevate the mandible?

Answer 16

• Temporalis
• Masseter
• Medial pterygoid

Question 17

What muscle primarily depresses the mandible?

Answer 17

Lateral pterygoid

Question 18

Which muscles are involved in the protrusion of the mandible?

Answer 18

• Lateral pterygoid
• Masseter
• Medial pterygoid

Question 19

What is the role of the lateral pterygoid during retrusion of the mandible?

Answer 19

Prime mover for retrusion

Question 20

How does the head of the mandible move during mouth opening?

Answer 20

Moves anteriorly on the articular surface until it lies inferior to the articular tubercle

Question 21

What are the four muscles of mastication?

Answer 21

• Temporalis
• Masseter
• Medial pterygoid
• Lateral pterygoid

Question 22

What nerve innervates the muscles of mastication?

Answer 22

Mandibular nerve (CN V3)

Question 23

What is the origin of the temporalis muscle?

Answer 23

• Floor of temporal fossa
• Deep surface of temporal fascia

Question 24

What is the action of the medial pterygoid muscle?

Answer 24

Acts synergistically with masseter to elevate mandible

Question 25

What is the course of the maxillary artery?

Answer 25

Arises posterior to the neck of the mandible and is divided into three parts

Question 26

What are the branches of the first part of the maxillary artery? ## Footnote Mandibular

Answer 26

- Deep auricular artery - Anterior tympanic artery - Middle meningeal artery - Accessory meningeal artery - Inferior Alveolar artery

Question 27

What does the middle meningeal artery supply?

Answer 27

- Periosteum, - bone, - red bone marrow, - dura mater of lateral wall - calvaria of neurocranium

Question 28

What is the location and orientation of the pterygoid muscle?

Answer 28

**Lateral Pterygoid Muscle**: *Location*: Infratemporal fossa. *Orientation*: Two heads (superior and inferior) with horizontal fibers. **Medial Pterygoid Muscle**: *Location*: Medial to the ramus of the mandible. *Orientation*: Fibers run downwards, backwards, and laterally

Question 29

What does the deep auricular artery supply?

Answer 29

- External acoustic meatus - External tympanic membrane - Temporomandibular joint

Question 30

What is the function of the anterior tympanic artery?

Answer 30

Supplies internal aspect of tympanic membrane

Question 31

What does the middle meningeal artery supply?

Answer 31

- Periosteum - bone - red bone marrow - dura mater of lateral wall and calvaria of neurocranium - trigeminal ganglion - facial nerve and geniculate ganglion - tympanic cavity - tensor tympani muscle

Question 32

Where does the accessory meningeal artery enter the cranial cavity?

Answer 32

Via foramen ovale

Question 33

What are the main structures supplied by the inferior alveolar artery?

Answer 33

- Mandible - Mandibular teeth - Chin - Mylohyoid muscle

Question 34

What does the masseteric artery supply?

Answer 34

- Temporomandibular joint - Masseter muscle

Question 35

What do the deep temporal arteries supply?

Answer 35

Mainly the temporalis muscle

Question 36

What do the pterygoid branches supply? ## Footnote Of Maxillary artery

Answer 36

Lateral & Medial Pterygoid muscle

Question 37

What does the buccal artery supply?

Answer 37

- Buccal fat-pad - Buccinator - Buccal oral mucosa

Question 38

What does the posterior superior alveolar artery supply?

Answer 38

Maxillary molar and premolar teeth, adjacent gingiva, and mucous membrane of maxillary sinus

Question 39

What is the route of the infra-orbital artery?

Answer 39

Traverses: - inferior orbital fissure, - infra-orbital groove, - canal, and - foramen

Question 40

What does the artery of pterygoid canal supply?

Answer 40

- Mucosa of upper pharynx - Pharyngotympanic tube - Tympanic cavity

Question 41

What does the pharyngeal branch supply? ## Footnote Of Pterygopalatine artery (of Maxillary artery)

Answer 41

- Mucosa of nasal roof - Nasopharynx - Sphenoidal air sinus - Pharyngotympanic tube

Question 42

What does the descending palatine artery divide into?

Answer 42

Greater and lesser palatine arteries

Question 43

What is the terminal branch of the maxillary artery?

Answer 43

Sphenopalatine artery

Question 44

Where is the pterygoid venous plexus located?

Answer 44

Partly between the temporalis and pterygoid muscles

Question 45

What is the function of the mandibular nerve?

Answer 45

Arises from the trigeminal ganglion and supplies the muscles of mastication

Question 46

What are the branches of CN V3?

Answer 46

* Auriculotemporal nerve * Inferior alveolar nerve * Lingual nerve * Buccal nerve

Question 47

What does the auriculotemporal nerve supply?

Answer 47

Sensory fibers to the auricle and temporal region

Question 48

What does the inferior alveolar nerve form in the mandibular canal?

Answer 48

Inferior dental plexus

Question 49

What does the lingual nerve provide sensory innervation to?

Answer 49

- Anterior two thirds of the tongue - Floor of the mouth - Lingual gingivae

Question 50

What nerve carries taste fibers from the anterior two thirds of the tongue?

Answer 50

Chorda tympani nerve

Question 51

Where is the otic ganglion located?

Answer 51

Infratemporal fossa, just inferior to the foramen ovale

Question 52

What type of fibers synapse in the otic ganglion?

Answer 52

Presynaptic parasympathetic fibers

Question 53

What gland receives postsynaptic parasympathetic fibers from the otic ganglion?

Answer 53

Parotid gland

Question 54

What are the branches of the second part of the maxillary artery? ## Footnote Pterygoid

Answer 54

- Masseteric artery - Deep temporal arteries - Pterygoid branches - Buccal artery

Question 55

What are the branches of the third part of the maxillary artery? ## Footnote Pteraygo-Palatine

Answer 55

- Posterior superior alveolar artery - Infra-orbital artery - Artery of pterygoid canal - Pharyngeal branch - Descending palatine artery - Sphenopalatine artery