The articular disc is a somewhat oval body of fibrous tissue, which is convex on its upper surface to accommodate itself to the shape of the articular fossa and concave on its inferior surface to conform to the head of the mandible.
Where is the articular disc found?
The articular disk is a thin, oval plate, placed between the condyle of the mandible and the mandibular fossa. Its upper surface is concavo-convex from before backward, to accommodate itself to the form of the mandibular fossa and the articular tubercle.
Why is the articular disc important?
Kinesiology of the temporomandibular joint The articular disc in the TMJ has an important functional role. It fills the space between the condyle and the temporal bone, and acts as a stress absorber and distributors during the jaw activity.
Which joint has articular disc?
Disks are found in the temporomandibular joint of the lower jaw, the sternoclavicular (breastbone and collarbone) joint, and the ulnocarpal (inner forearm bone and wrist) joint.Is articular disc avascular?
In young puppies, the degree of vascular penetration into the disc is quite extensive, while in adult animals it ranges from 15 to 25% of the discal width; the considerably larger central area of the articular disc is thus avascular.
What muscle attaches to the articular disc of the TMJ?
The masseter muscle with its perimysium has direct contact with the articular disc on the front edge. It originates from the zygomatic arch with several muscular layers and inserts on the branch of the mandible (lateral surface) and the coronoid process (lateral surface).
Do articular discs move freely?
Structure of diarthrodial joint or synovial joint Diarthrodial joints are freely moving joints wherein the joint is encased in an articular capsule, and the bones connect with each other in a fluid-filled cavity known as the synovial cavity. The articular capsule is made up of cartilage and fibrous tissues.
Is the meniscus an articular disc?
Anatomical Parts The articular disk(meniscus) is a thin, oval plate of fibrocartilage present in several joints which separates synovial cavities. This separation of the cavity space allows for separate movements to occur in each space.What attaches to the articular disc?
Capsule – The capsule is a fibrous membrane that surrounds the joint and attaches to the articular eminence, the articular disc and the neck of the mandibular condyle.
Where is Amphiarthrosis located?Another example of an amphiarthrosis is the pubic symphysis of the pelvis. This is a cartilaginous joint in which the pubic regions of the right and left hip bones are strongly anchored to each other by fibrocartilage. This joint normally has very little mobility.
Article first time published onDo all synovial joints have articular discs?
Many, but not all, synovial joints also contain additional structures: Articular discs or menisci – the fibrocartilage pads between opposing surfaces in a joint. Articular fat pads – adipose tissue pads that protect the articular cartilage, as seen in the infrapatellar fat pad in the knee.
Does the elbow have an articular disc?
The articular disc is attached to the ulnar styloid by its apex and by its base to the radius. The disc slides over the ulnar end during pronation and supination of the forearm.
What are articular discs as the one in the temporomandibular joint made of?
Articular disk of the temporomandibular jointTA21623FMA57059Anatomical terminology
Does sternoclavicular joint have articular disc?
The sternoclavicular joint (SCJ) has a complete intra-articular disk that can be damaged either as a result of trauma or as part of ongoing degenerative joint disease. Although often asymptomatic, SCJ disk tears may lead to mechanical symptoms and pain.
What muscles deviate the jaw?
The temporal muscles, working independently on one side, will deviate the jaw outward to the same side, whereas each of the masseter and pterygoid muscles will act to protrude the jaw on the opposite side.
What are articular disc made of?
The articular disc of the temporomandibular joint (TMJ) is composed of fibrocartilage, and the extracellular matrix of this disc is composed mainly of collagen, glycosaminoglycan and proteoglycans.
What is articular capsule?
In anatomy, a joint capsule or articular capsule is an envelope surrounding a synovial joint. Each joint capsule has two parts: an outer fibrous layer or membrane, and an inner synovial layer or membrane.
What is the articular tubercle of temporal bone?
The articular tubercle (eminentia articularis) is a bony eminence on the temporal bone in the skull. It is a rounded eminence of the anterior root of the posterior end of the outer surface of the squama temporalis.
Is articular cartilage and meniscus same thing?
Articular cartilage forms the smooth layer of the joint that covers the ends of bones. A layer of this cartilage covers the end of the thigh bone, the top of the shin bone, and the back of the kneecap. The meniscus is a different type of cartilage. This type acts as a shock absorber between bones.
What makes up articular cartilage?
Articular cartilage is hyaline cartilage and is 2 to 4 mm thick. Unlike most tissues, articular cartilage does not have blood vessels, nerves, or lymphatics. It is composed of a dense extracellular matrix (ECM) with a sparse distribution of highly specialized cells called chondrocytes.
What does articular cartilage look like?
Articular cartilage is the smooth, white tissue that covers the ends of bones where they come together to form joints. Healthy cartilage in our joints makes it easier to move. It allows the bones to glide over each other with very little friction.
What joints are amphiarthrosis?
Type of Joint FunctionExamplesAmphiarthrosis (range of joint motion: little Movement)distal joint between the tibia and the fibula and the pubic symphysisDiarthrosis (range of joint motion full movement)Elbow, shoulder, ankle
Why is amphiarthrosis important?
A slightly moveable amphiarthrosis provides for small movements, which in the vertebral column can add together to yield a much larger overall movement. The freedom of movement provided by a diarthrosis can allow for large movements, such as is seen with most joints of the limbs.
Are all cartilaginous joints amphiarthrosis?
Symphyses are found at the joints between vertebrae and between the pubic bones. Amphiarthroses allow only slight movement; therefore, either type of cartilaginous joint is an amphiarthrosis.
Do synovial joints have articular cartilage?
Articular Cartilage The articulating surfaces of a synovial joint (i.e. the surfaces that directly contact each other as the bones move) are covered by a thin layer of hyaline cartilage. The articular cartilage has two main roles: (i) minimising friction upon joint movement, and (ii) absorbing shock.
What type of synovial joint is carpal carpal?
The other 4 carpometacarpal joints are plane type synovial joints, formed by the articulations between metacarpals 2 through 5 and the distal row of the carpal bones..
What happens when articular cartilage begins to erode from excessive wear and stress on a joint?
Patients with damage to the cartilage in a joint (articular cartilage damage) will experience: Inflammation – the area swells, becomes warmer than other parts of the body, and is tender, sore, and painful. Stiffness. Range limitation – as the damage progresses, the affected limb will not move so freely and easily.
What three structures are intra-articular?
The intra-articular ligaments are the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and the posterior meniscofemoral ligament. (See the image below.)
What is the articular surface of a bone?
A joint or articulation (or articular surface) is the connection made between bones in the body which link the skeletal system into a functional whole. They are constructed to allow for different degrees and types of movement.
What artery supplies the TMJ?
The temporal superficial and internal maxillary arteries supply the TMJ through the auricular root. Both of these arteries arise from the external carotid.
What is articular disc in clavicle?
Anatomical terminology. The articular disc of the sternoclavicular joint is flat and nearly circular, interposed between the articulating surfaces of the sternum and clavicle.
