Head and Neck Anatomy 2 Flashcards
What does psychosomatic mean?
A disease or disorder produced by a result of a mental factor
What are the different bones of the TMJ?
- Head of the mandible
- Mandibular fossa
- Articular tubercle
What are the ligaments of the TMJ?
- Spheno-mandibular ligament
- Lateral ligament
What does the TMJ consist of?
- Bones
- Ligaments
- Capsule
- Muscles attaching to or near the joint
- Synovial joint/fibrocartilaginous disc
What does the articular disk allow the TMJ to do?
Allows it to move smoothly
Which muscle is the only one that opens the mouth?
The lateral pterygoid
How is the mandible formed?
By the union, in the midline, of two halves each having a horizontal body and a vertical ramus
Where is the angle of the mandible formed?
Where the ramus and the body meet
What does the ramus of the mandible consist of?
It is flat and has 2 processes at the superior end: coronoid process and condylar process (or head)/ mandibular notch and foramen (where the nerve that supplies the lower teeth is)
What does the body of the mandible consist of?
- Mental foramen
- Mylohyoid line
- Mental spine
- Mylohyoid line and mental spine in the inside of the mandible
- Mental spine - slight projection for muscle attachment
Where does the inferior alveolar nerve come out of the mandible from?
The mental foramen
What are the parts of the temporal bone included within the TMJ?
- Mandibular fossa
- Articular tubercle of the squamous temporal bone
What are the functions of the capsule?
1) Attachments
2) Thickenings; lateral ligament
What are the accessory ligaments of the synovial joint?
Spheno-mandibular and stylo-mandibular
The articular surface of the synovial joint is covered with a fibro-cartilage. What is this fibro-cartilage called?
Hyaline cartilage
What does the synovial joint allow for?
Movement
Where the bones meet to form the synovial joint, the bone surface are covered with a thin layer of strong, smooth cartilage. What is this cartilage called?
Articular cartilage
What does synovial fluid do?
Separates and lubricates the two cartilage-covered bone surfaces
What is the synovial membrane at the synovial joint?
- It encapsulates the joint surfaces and synovial fluid
- It is very thin, often just a few cells thick and produces synovial fluid
- It is backed by a slightly thicker sub-synovial membrane
What is dangerous about the styloid process?
- Internal carotid artery is right next to the styloid process
- If the styloid process is very long it can actually kill
What does the styloid process do?
- Attaches to stylomandibular ligament
- Helps stabilise joint
There is a fibrocartilaginous disc whose margins are attached to the capsule: this divides the cavity into a superior and inferior compartment. What is the shape of the disc and what is the function?
- Concave under surface and concavo-convex upper surface
- Gliding (upper compartment) and hinge movement (lower compartment)
What is the name for opening the mouth in relation to the mandible?
Depression
What is the name for closing the mouth in relation to the mandible?
Elevation
What is the name for sticking the jaw further out in relation to the mandible?
Protrusion
What is the name for pulling the jaw inwards in relation to the mandible?
Retraction
When does the mandible have greatest stability?
When the mandible is elevated as teeth are occluded and the condyle is secure in the articular fossa - so when mouth is shut and resting
When is the TMJ unstable?
When talking and chewing
What is the most common injury of the TMJ?
Forward dislocation
What is the blood supply to the TMJ?
- External carotid artery: superficial temporal and maxillary branches
What is the nerve supply to the TMJ?
- Auriculotemporal and masseteric nerves which are both derived from the trigeminal nerve
What is fascia?
A sheet or band of fibrous tissue
What are the 4 muscles of mastication?
- Masseter
- Temporalis
- Lateral pterygoid
- Medial pterygoid
Which is the only muscle of mastication that opens the mouth?
Lateral pterygoid
Where does the medial pterygoid attach to and what is its function?
- Arises from the medial surface of the lateral pterygoid plate and inserts onto the medial surface of the angle of the mandible and ramus
- Elevates and protrudes the mandible
Where does the lateral pterygoid attach and what is its function?
- Arises infratemporal surface of the greater wing of sphenoid and lateral surface of the lateral pterygoid plate and inserts into the neck of the mandible at the fovea and to the capsule and the intra-capsular disk
- Depresses and protrudes the mandible
