Lecture 27 Flashcards
TMJ
Tempormandibular Joint
What type of joint is the TMJ?
Hinge and gliding (for chewing)
TMJ actions?
- elevation/depression
- retraction/protraction
- lateral deviation
Four muscles of mastication
- masseter
- temporalios
- medial pterygoid
- lateral pterygoid
What is, pound for pound, the strongest muscle in the body?
Masseter
What are the muscles of mastication innervated by?
Mandibular branch of the Trigeminal Nerve
Whenever the jaw is OPEN, two things ALWAYS occur:
- the mandibular condyle is displaced anteriorly (partially dislocates)
- mandible is depressed
What muscles CLOSE the jaw?
- masseter
- temporalis
- medial pterygoid
What muscles form the “mandibular sling,” and what do they do?
- masseter and medial pterygoid
- closing the mouth
What causes the mandible to PROTRUDE, and also initiates DEPRESSION (opening)?
lateral pterygoid
What other muscles help the mandible with depression/opening?
Suprahyoid group
- Mylohyoid
- Anterior belly of the digastric
- Geniohyoid
Ligaments of the TMJ (5)
- Articular capsule
- Articular disk
- Temporomandibular ligament
- Stylomandibular ligament
- SPhenomandibular ligament
Contents of infra temporal joint (10 things: 5 nerves, 1 vein, 1 artery, 2 muscles, and 1 ganglion)
- maxillary artery and branches
- pterygoid plexus of veins
- medial and lateral pterygoid muscles
- otic ganglion
- auriculotemporal nerve (branch of v3)
- buccal nerve
- inferior alveolar nerve, with branch to the mylohyoid
- lingual nerve
- termination of chord tympani nerve
Parasympathetic/preganglionic
- myelinated
- longer course (to ganglion)
- increase secretion
Sympathetic/postganglionic
- unmyelinated
- shorter course (to gland)
- dries up secretion
