Flashcards in H&N Deck (409)
Describe the C1 vertebra
Has articulating processes
No body or spinous process
Ant and post. arches, 2 lateral masses
Sup. surfaces of lateral masses articulate with occipital condyles
Describe the axis
2nd cervical vertebra
Has dens that projects sup. into ant. arch of atlas
Allows pivot for rotation of atlas
What are the 2 movements involved in the vertebral column?
Atlanta-Occipital - nodding (yes)
Atlantoaxial - rotation (no)
What is whiplash and how does it happen?
Rapid flexion/extension injury in cervical region
Strains post. ligaments
Can dislocate post. apophyseal joints
C7 likely site for fracture
Describe the structure of intervertebral disks
Nucleus pulposus- gel-like mass in centre, allows disk to expand
Annulus fibrosus - layers of fibrocartilaginous material
What is the TMJ?
Bilateral synovial joint formed from articulation of mandible and temporal bones
What are the 4 suprahyoid muscles?
What is the function of the suprahyoid muscles?
Elevate or retract hyoid during swallowing
Describe the mandibular condyle
Has articulating surface/head covered with hyaline cartilage, narrows down to neck
Lateral and medial poles
Pterygoid fovea - depression left by muscles of mastication
Important growth site - grows forward and down
Articulates in mandibular fossa of temporal bone
What are the main features of the mandible?
Describe where the mandibular fossa are and the articular surface
R and L temporal bones
Articular surface covered by dense fibrous articular tissue
What are the lateral, medial, ant. and post. boundaries of the mandibular fossa?
Lateral: zygomatic process of temporal bone
Medial: spine of sphenoid bone
Ant: articular eminence
Post: squamotympanic and petrotympanic fissures
What is the function of the joint capsule of the TMJ?
Encloses joint like a sleeve, preventing it from slipping out of fossa
Describe the location and composition of the joint capsule
Runs post. from temporal bone to mandible condyle infer.
Made of fibrous tissue
What are the superior attachments of the joint capsule?
Area surrounding mandibular fossa and articular eminence
Extends ant. to ant. slope of articular eminence, post. to squamotympanic fissur
What is the attachment site of the joint capsule to the periphery condyle neck and below the medial and lateral poles of condylar neck?
Describe the temporomandibular ligament
Lateral thickening of the capsule strengthening the capsule laterally
Runs from zygomatic process of temporal bone to lateral surface of mandibular neck
What is the articulating dick?
Dense fibrous tissue lying inside joint capsule dividing joint cavity into sup. and infer. compartments allowing for separate movement in each compartment
Describe the location and anatomy of the articulating disk
Prominent post. thickening, less prominent ant. thickening
Lies between condyle and mandibular fossa
What are the 2 accessory ligaments of the temporomandibular joint?
Stylomandibular: styloid process to angle of mandible
Sphenomandibular: spine of sphenoid to lingula
What are the 5 movements of the TMJ?
What nerve supplies the TMJ?
Sensory division of auriculotemporal nerve
What 2 arteries supply the TMJ?
Superficial temporal artery
Small contribution from maxillary artery - supplies the ant. aspect of TMJ
How is TMJ dysfunction usually detected?
Pain and clicking/popping sound
What is arthritis?
Joint inflammation resulting in breakdown of articular cartilage
How can arthritis be caused?
Age - primary degenerative
Abnormal function - 2ndary degenerative
What can cause 2ndary arthritis?
Bruxism - grinding teeth, stress on TMJ
Malocclusion - X-bite; mandibular teeth enclose maxillary teeth
Describe internal disk derangement
Articulating disk doesn't move in sync with condyle
Fibres pull disk through joint causing popping sound
Describe dislocation of the TMJ
Head of condyle comes out of mandibular fossa
Can be caused by excessive pressure on mandible such as extraction, big yawn or by trauma