TMJ
I like to bite
histology is lit
lock jaw
i love to study
jaw clicks
100
secondary joints
bone->cartilage->fibrous tissue->cartilage->bones
100
Medial pterygoid
closes the mouth
100
Bones of the TMJ
Glenoid fossa
Condyle of the mandible
Mandible
Condole
100
Masseter
closes the mouth (second biggest)
100
primary joints
bone and cartilage in direct apposition
100
Innervation of the joint type 3
Type 3: Golgi Tendon organs- limited to ligaments
200
Capsular ligament
Divides the joint into two compartment (upper/lower)
Upper is fibrous/elastic and lower is collagen/nonelastic
Resist medial, lateral or inferior forces
Surrounds the joint and holds synovial fluid
Discal (collateral) ligament
-extends from disk
-collagenous
200
2 types of cartilaginous joints
primary and secondary
200
Suture
-permits little to no movement
-functions to allow growth (skull sutures)
200
Muscles contraction
Fasciculi muscle cell bundles
-Sarcolemma- cell membrane of the fiber
-Sarcoplasm-packed with myofibrils and mitochondria
200
Condyle of the mandible
articulating surface of the mandible, the surface is covered by hyaline cartilage
-temporomandibular articulation is covered by layer of fibrous tissue
-the condyle is formed by endochondral ossification
-the mandible and every other flat bone is intramembranous ossification
300
Gomphosis
-movement is restricted, like socketed attachment of tooth to bone by the PDL
300
Temporalis
(biggest)
-closes the mouth
300
3 fibrous joints
suture, gomphosis, syndesmosis
300
Sphenomandibular ligament
one of the accessory ligaments
-keeps the mandible from slipping away
300
Synovial membrane
-lines inner surface of the capsule
-it produces synovial fluid, the fluid lubricates and reduces erosion
400
Disc
-fibrous connective tissue
-concave lower, convex upper
-makes only short movements to fit the changing relationship of the condyle and the glenoid fossa
400
White muscles
-fast, rapid fatigue, anaerobic
-few mitochondria
400
Glenoid fossa
the undersurface of the squamous part of the temporal bone
400
Syndesmosis
two bones some distance apart connected by an interosseous ligament, like fibula and tibia
400
Muscles of mastication (biggest to smallest)
Temporalis
Masseter
Medial pterygoid
Lateral pterygoid
500
Red muscle
slow but sustained, resistant to fatigue, aerobic
-poor myofibrils but many mitochondria
500
Classification of joints
Fibrous (3 types)
-two bones connected by fibrous tissue
Cartilaginous (2 types)
-comes in two forms
Synovial
-allows significant movement, 2 bones connected and surrounded by a capsule (TMJ)
500
Stylomandibular ligament
second accessory ligament
-limits excessive protrusive movements of the mandible
500
Temporomandibular ligament (or lateral ligament)
Two parts
-outer oblique: resists excessive dropping of the condyle
-inner horizontal: limits posterior movement
500
Synovial joint
articular surface covered by hyaline cartilage
-the cavity is filled by synovial fluid formed by synovial membrane, it reduces friction between the joint
-may be separated by an articular disk like the TMJ
-the bone can move uniaxial (one way), biaxial (2), multiaxial
-they can be shaped like a pivot, planar, ginglymoid, arthroid, condyloid, saddle and ball-and-socket
500
Nerve innervation of TMJ
Mandibular branch of Trigeminal nerve
-auriculotemporal
-masseteric
-deep temporal
600
Lateral pterygoid
-superior head closes the mouth
-inferior head opens the mouth
600
Innervation of Joints type 1
Type 1: Ruffini corpuscle (prioception)
600
Innervation of the joint type 2
Type 2: Pacinian corpuscle (mechnoreceptor)
600
External carotid artery
600
Blood supply to TMJ
External carotid artery
-superficial temporal
-deep auricular
-ascending pharyngeal
-anterior tympanic
600
Innervation of the joint type 4
Type 4: Free endings (noiception)- most abundant and it's for pain