68. Muscles of mastication Flashcards
Identify
- Temporalis muscle
- Insertion of masseter muscle (cut away)
- Buccinator muscle
- Orbicularis oris muscle
muscles of mastication
- are derived embryologically from ____
- are innervated by ___
- the 1st pharyngeal (branchial) arch
- the mandibular division of the trigeminal nerve (CN V3)
Identify 1. O & I
- Temporalis muscle
Origin: Temporalis muscle arises from the floor of the temporal fossa and the deep surface of the temporal fascia.
Insertion: The tip and medial surface of the coronoid process and anterior border of the ramus of the mandible.
Identify 1. Action
- Temporalis muscle
Action:
Elevates mandible Retrudes mandible (posterior fibers)
Identify 1. Innervation
- Temporalis muscle
Innervation: Anterior and posterior deep temporal nn. from mandibular division of trigeminal n.
Which muscle is the Main postural muscle that maintains mandible in rest position?
Temporalis muscle
What are the 4 muscles of mastication?
- Temporalis muscle
- Masseter muscle
- Medial pterygoid muscle
- Lateral pterygoid muscle
Identify
- Masseter muscle
- Parotid duct (cut)
- Buccinator muscle
- Temporalis muscle
1 artery, 1 structure and nerves that pass superficial to masseter
Parotid duct, transverse facial a., and branches of facial n.
Identify 1. O & I
- Masseter muscle
Origin: Masseter muscle arises from the inferior border and medial surface of the zygomatic arch.
Insertion: Massester muscle attaches to the lateral surface of the mandible and lateral surface of the coronoid process.
Identify 1. Action
- Masseter muscle
Action: Masseter muscle closes the jaw by elevating the mandible.
Identify 1. Innervation?
- Masseter muscle
Innervation: Masseteric n. from mandibular division of trigeminal n.
Identify
- Masseter (deep head)
- Masseter (superficial head)
Structure that pierces the buccinator muscle?
the parotid duct which drains the parotid gland
Elevation of the jaw (except masseter m.) also is assisted by the actions of ____ (2 muscles)
the temporalis and medial pterygoid muscles.
Identify 1 - 3
- Medial pterygoid muscle
- Sphenomandibular ligament
- Levator veli palatini muscle (cut)
Identify 4 - 6
- Tensor veli palatini muscle (cut)
- Lateral pterygoid muscle
- Pterygoid hamulus
Identify 1. O & I
- Medial pterygoid muscle
Origin: Medial pterygoid muscle arises from 2 slips. Its deep head arises from the medial surface of the lateral pterygoid plate and pyramidal process of the palatine bone. Its superficial head arises from the tuberosity of the maxilla.
Insertion: The fibers of the medial pterygoid muscle blend to attach to the medial surface of the ramus of the mandible
Which artery runs superficial or deep to lateral pterygoid muscle?
Maxillary a.
Medial pterygoid muscle arises from 2 slips.
- Its deep head arises from ___ AND ____
- Its superficial head arises from___
- the medial surface of the lateral pterygoid plate and pyramidal process of the palatine bone.
- the tuberosity of the maxilla.
Identify 1. Actions
- Medial pterygoid muscle
Actions:
- Depresses mandible
- Protrudes mandible
- Lateral excursion of mandible
Identify 1. Nerve
- Medial pterygoid muscle
Nerve: Medial pterygoid branch of mandibular division of trigeminal
Identify
- Deep head of the medial pterygoid m.
- Superficial head of the medial pterygoid m.
Identify
- Deep head of the medial pterygoid m.
Medial pterygoid muscle helps close the jaw by ____
elevating the mandible.
With the lateral pterygoids, what do the 2 medial pterygoids do?
protrude the mandible.
When 1 medial and 1 lateral pterygoid on the same side of the head act together, what are the actions of the mandible?
the mandible is protruded forward and to the opposite side
Identify
- Superior head of the lateral pterygoid m.
- Inferior head of the lateral pterygoid m.
Identify
- Superior head of the lateral pterygoid m.
- Inferior head of the lateral pterygoid m.
Identify
- Superior head of the lateral pterygoid m.
- Inferior head of the lateral pterygoid m.
Identify 1 → 2
- Lateral pterygoid muscle
- Articular disc of temporomandibular joint
Identify 3 → 5
- Sphenomandibular ligament
- Medial pterygoid muscle
- Buccinator muscle
Identify 1. O & I
- Lateral pterygoid muscle
Origin: The superior head arises from the infratemporal surface and infratemporal crest of the greater wing of the sphenoid bone. The inferior head arises from the lateral surface of the lateral pterygoid plate.
Insertion: the pterygoid fovea on the front of the neck of the mandible, articular disc, and capsule of the temporomandibular joint.
- Lateral pterygoid muscle
- The superior head arises from ____
- The inferior head arises from ____
- Lateral pterygoid muscle
- the infratemporal surface and infratemporal crest of the greater wing of the sphenoid bone.
- the lateral surface of the lateral pterygoid plate.
Identify 1. Actions
- Lateral pterygoid muscle
Actions:
- Depresses mandible
- Protrudes mandible
- Lateral excursion of mandible
Identify 1. Innervation
- Lateral pterygoid muscle
Innervation: Lateral pterygoid branches (for each head) of mandibular division of trigeminal
Which nerve passes between the 2 heads of lateral pterygoid muscle?
Buccal branch of trigeminal n.
Lateral pterygoid muscle assists in opening the mouth by drawing ___ and ____ forward.
the condyle of the mandible and articular disc of the temporomandibular joint
With the medial pterygoid of the same side, the lateral pterygoid protrudes the mandible.
→ The jaw is rotated to the opposite side, producing____
a grinding movement.
The other 3 muscles of mastication help close the jaw, whereas ____ opens the jaw
Lateral pterygoid muscle
The other 3 muscles of mastication help close the jaw, whereas the lateral pterygoid opens the jaw.
→ At the beginning of this action, it is assisted by ___ (3 muscles)
the mylohyoid, digastric, and geniohyoid muscles.
