QUIZ 4 TMJ

Question 1

do fibrous joints permit a lot of movement?

Answer 1

no, they generally permit very little movement

Question 2

what are exmples of fibrous joints?

Answer 2

• sutures in the skull
• tooth socket - gomphosis
• syndesmosis - immovable connective tissue holding bones together (ex. the tibia and fibula)

Question 3

do cartilagenous joints permit a lot of movement?

Answer 3

no, they generally permit very little movement (like fibrous joints)

Question 4

what are examples of cartilagenous joints?

Answer 4

• primary cartilagenous joints
• secondary cartilagenous joints

Question 5

what are primary cartilagenous joints?

Answer 5

• synchondroses
• bone and cartilage in direct apposition
• ex. sternocostal junction

Question 6

what are secondary cartilagenous joints?

Answer 6

• symphyses
• fibrous tissue internally in the joint

Question 7

___ joints consist of a capsule filled with fluid contained in a membrane

Answer 7

• synovial
• *synovial fluid in a synovial membrane

Question 8

movement of bones relative to one another, facilitated by muscle, take place in ___ capsules in ___ joints

Answer 8

• articular capsule (fibrous capsule + synovial membrane)
• synovial

Question 9

how are types of synovial joints classified?

Answer 9

based on how many axes they can move along and also by the shapes of their articular surfaces

Question 10

the TMJ is a ___ joint

Answer 10

synovial sliding-ginglymoid

Question 11

the TMJ articulation is composed of the ___ of the mandible and the ___ of the skull, which is indented on the underside of the ___ bone

Answer 11

• condyle
• glenoid fossa
• temporal

Question 12

what types of movements does the TMJ need to produce?

Answer 12

protrusive, extrusive, and retrusive movements

Question 13

the ___ provides a track that the condyle slides along. theis is bounded anteriorly by the ___, which the condyle moves in front of when the jaw opens

Answer 13

• glenoid fossa
• articular eminence

Question 14

the condyle is able to ___ and ___ in various ways

Answer 14

rotate and translate

Question 15

is the articular disk a distinct structure?

Answer 15

no, it is an extension of the synovial capsule

Question 16

the synovial cavity is divided into two compartments. describe this.

Answer 16

• the compartments are divided by the articular disk
• upper joint cavity - adjacent to the glenoid fossa
• lower joint cavity - adjacent to the condyle

Question 17

the articular disk runs between and attaches the ___ and ___, enveloping the joint

Answer 17

condyle and glenoid fossa

Question 18

the mandible is formed by ___ ossification

Answer 18

intramembranous ossification

Question 19

the mandible is associated with ___ cartilage

Answer 19

meckel’s

Question 20

meckel’s cartilage forms the ___ directly and articulates with the ___. this forms a primitive, or primary joint, before the deveopment of the ___ and ___.

Answer 20

• malleous
• incus
• condyle
• tempral bone

Question 21

the articulation between the temporal bone and the condyle forms the ___

Answer 21

TMJ - this is the secondary joint

Question 22

the articular surfaces of the TMJ are covered with a ___, as opposed to ___

Answer 22

• fibrous connective tissue
• hyaline cartilage

Question 23

what is the fibrous covering of the condyle called?

Answer 23

lamina splendens

Question 24

what is the lamina splendens?

Answer 24

• fibrous covering of the condyle that is a layer of mostly avascular type I collagen with some fibroblasts scattered around

Question 25

the glenoid fossa is covered by a ___ layer attached directly to the \_\_\_, while the articular eminence is overalid by a ___ layer

Answer 25

* thin fibrous * temporal bone * much thicker fibrous

Question 26

is there cartilage associated with the articular surfaces of the joint proper?

Answer 26

no - it is fibrous connective tissue

Question 27

where is cartilage found?

Answer 27

deeper into the condyle and the articular eminence

Question 28

the layers of cartilage found deep in the condyle and the articular eminence have a layer of progenitor cells which spawn ___ in a proliferative layer, which in turn secrete ECM containing type ___ collagen around themselves

Answer 28

* chondroblasts * II

Question 29

cartilage has what type of collagen?

Answer 29

II

Question 30

the joint capsule forms the ___ that the joint is located within

Answer 30

dense collagenous sac

Question 31

the joint capsule has thickened regions which branch out to form the \_\_\_

Answer 31

temporomandibular ligament

Question 32

the temporomandibular ligament is important for restricting ___ and ___ movements when the joint articulates

Answer 32

lateral and medial

Question 33

the temporomandibular ligament restricts movement in what 3 planes?

Answer 33

* medial-lateral * superior-inferior * posteriorly * when the joint moves, it is displaced mainly in an anterior direciton due to these limits

Question 34

what are two other ligaments associated with the TMJ that limit the **inferior** movement of the jiont when the jaw is open?

Answer 34

* sphenomandibular ligament * stylomandibular ligament

Question 35

the articular disk is totally continuous with the \_\_\_; it is simply an inward branch of it

Answer 35

joint capsule

Question 36

the articular disk is a ___ structure and forms a surface for the ___ to slide along when the jaw opens; a ___ networks overlays ___ cells

Answer 36

* dense fibrous * head of the condyle * collagen fiber * fibroblast

Question 37

is the articular disk bound tightly or loosely to the surface of the condyle?

Answer 37

tightly - it matches the contour of the condyle surface

Question 38

the articular disk is thicker in which regions? which region is thinner?

Answer 38

* it is thicker posteriorly and anteriorly * middle section is thinner

Question 39

when the jaw is closed, the condyle rests on which part of the articular disk?

Answer 39

the thinner, middle section

Question 40

the joint capsule is lined by the \_\_\_, and contains a number of folds which form ___ projecting into the \_\_\_

Answer 40

* synovial membrane * villi * joint cavity

Question 41

what are the two layers that the synovial membrane consists of?

Answer 41

subintima and intima

Question 42

describe the subintima

Answer 42

* layer of the synovial membrane that consists of loose connective tissue containing elastin fibers and supporting vasculature * contains macrophages, adipocytes, fibroblasts, mast cells, and possibly others * it is more or less continuous with the fibrous tissue of the capsule

Question 43

describe the intima

Answer 43

* innermost layer of the synovial membrane * contains several layers of synovial cells, which can be either A cells (resemble macrophages) or B cells (like fibroblasts but contribute proteins found in the synovial fluid)

Question 44

describe the synovial fluid

Answer 44

basically blood plasma containing extra proteins and proteoglycans

Question 45

what are the 4 muscles of mastication?

Answer 45

masseter, medial pterygoid, lateral pterygoid, and temporalis