Joints Flashcards
(43 cards)
What is arthrology?
The study of joints (articulations).
When is an articulation formed?
A joint (articulation) is formed when bones interact/come into contact.
What is the function of joints?
Joints hold the bones in their proper location and orientation. Joints also provide for different degrees of movement between the articulated bones.
What are the 2 types of articulations?
Bone to bone and bone to cartilage.
What is a simple joint system?
Neuro-mechanical basis of kinesiology. It is composed of a rigid link, a joint, a muscle, a neuron, and a sensory receptor.
What is the origin attachment site?
An attachment site for a less movable bone more fixed bone. Usually, proximal.
What is the insertion attachment site?
An attachment site for a more moveable bone. Usually, distal.
What is the action within a joint?
The mechanical outcome of a muscle contraction (Flexion of the radius ulna to
reduce the angle between anterior surfaces).
What are the muscles within an antagonistic couple?
The agonist (muscle that contracts to create most of the desired muscle action), the synergist (helps the agonist by stabilising the joint), the fixator (stabilises the origin of the agonist and the joint that the origin spans), and the antagonist (a muscle that opposes the action of the agonist, undoing the desired action).
What are the 2 systems joints that can be classified based on?
Functional and structural classification.
What is structural classification?
It is based on how the bones are attached/associate to each other /together i.e., what tissue binds bones together and presence or absence of a joint cavity.
What are the types of functional classifications?
- Synarthroses – immovable – common in axial skeleton
- Amphiarthroses – slightly movable – common in axial skeleton
- Diarthroses – freely movable – common in appendicular skeleton
What is functional classification?
It is based on how much movement is facilitated at each joint.
Can joints be classified under both functional and structural classifications?
Yes, e.g. Tempro-mandibular joint is both diarthrosis & Synovial.
What is a synarthrosis joint?
Immovable joint, there exists no articular cavity or separation between bones.
(Cartilaginous and Fibrous).
What are the 3 types of synarthrosis joints?
Suture, synchondroses and gomphosis joints.
What is an amphiarthrosis joint?
Slightly moveable, no joint cavity and the bones are held together by cartilage, fibrous
tissue.
What are the 2 types of amphiarthroses joints?
Syndemosis (bones connected by ligaments) and symphysis (bones separated by fibrocartilage).
What is a diarthrosis joint?
Freely Moveable; joint cavity present and the bones forming the joint are surrounded by articular capsule and accessory ligaments (Synovial).
What are the characteristics of a diarthrosis joint?
- An articular cavity is present.
- The joint is enclosed within a sleeve-like ligamentous capsule.
- The bi-layered capsule is lined with a synovial membrane that secretes synovial fluid for lubricating the joint.
- The articular surfaces are smooth.
- The articular surfaces are covered with specialised hyaline cartilage (no perichondrium and increased water content).
What are the six sub-types of synovial/diarthrosis joints?
- Planar: gliding joints (non-axial)
- Ginglymus: Hinge joints (mono-axial)
- Trochoid (mono-axial)
- Ellipsoidal (bi-axial)
- Sellaris (bi-axial)
- Spheriod (tri-axial)
What is a planar gliding joint?
A flat articular surface permits non-axial movement in single plane at right angle to each other. Twisting and rotation are restricted.
What is a ginglymus hinge joint?
A convex surface fits into a concave surface of another bone. It provides for mono-axial motion and usually allows flexion and extension in plane.
What is a trochoid joint?
A rounded or pointed surface articulates with a ring formed partly by another bone. It is a mono-axial joint.
