Mastication muscles Flashcards Preview

NBDE Anatomic Sciences > Mastication muscles > Flashcards

Flashcards in Mastication muscles Deck (14):
1

Lateral pterygoid

supeprficial head

O

I

O: greater wing of spenoid (infratemporal) lateral surface

I: articular disc and capsule of TMJ

2

Lateral pterygoid

Inferior head

I

O: Lateral pterygoid plate lateral surface

I: Ramus (lateral), condylar neck (process)

3

Lateral pterygoid action

Protrude (pulls articular disc forward)

Depresses

Excursion

4

Lat pterygoid assoc structures

Maxillary artery runs superficial or deep

Pterygoid venous plexus

CN 5 buccal branch runs btw the 2 heads

5

Medial pterygoid

Superficial head

O

I

O: Maxillary tuberosity

I: Medial surface of ramus and angle

6

Medial pterygoid

Deep head

O

I

O: Lateral pterygoid, medial surf

Medial pterygoid plate, lateral surface

Pterygoid fossa

I: Medial surface of ramus and angle

7

Medial pterygoid action

Elevates

Protrudes

Excursion

8

Medial Pterygoid assoc structures and special note

  • Deepest muscle of mastication
    • Can penetrate during mandibular block if needle is placed below the mandibular foramen
  • Contacts
    • Parotid Gland
    • Inferior alveolar ARTERY
    • Inferior alveolar NERVE
    • Lingual NERVE
    • Chorda tympani N

9

Masseter 

Superficial Head

O

I

Size and fibers

  • Larger, fibers run down and back 
  • O: Anterior 2/3 zygomatic
  • I: Lateral surface of ramus

10

Masseter

Deep head

O

I

Size and fibers

  • Smaller, fibers run vertical
  • O: Post 2/3 zygomatic 
  • I: :ateral of ramus and coronoid

11

Masseter action

Elevate (Clenching)

Superficial head protrudes

Excursion

12

Masseter assoc structures

Superficial to masseter

Parotid gland 

Tranverse facial artery

Branches of CN 7

13

Temporalis

O

I

  • O: Temporal fossa, inferior temporal line, fascia
  • I: Travels under zygomatic arch
    • Coronoid process
    • Anterior border of ramus

14

Temporalis Action

  • Anterior vertical fibers
    • Elevate
  • Middle/oblique and posterior horizontal
    • Retract mandible
  • Keeps jaw in resting position