Joint Pain and Approaches to Arthritis Flashcards
___ are the most common type of joint in the body.
Synovial joints are the most common type of joint in the body.
Three types of joints
Synovial
Fibrous
Cartilagenous
The key feature that distinguishes synovial joints from fibrous and cartilagenous joints is the presence of ____.
The key feature that distinguishes synovial joints from fibrous and cartilagenous joints is the presence of a joint cavity.
Articular capsule
Articular cartilage is always made of ____.
Articular cartilage is always made of hyaline cartilage.
Synovial fluid
“synovia” = thick fluid
A thick, slimy fluid that provides further lubrication in synovial joints. Also nourishes the articular cartilage, which is avascular. Essentially an ultra-filtrate of plasma with some added proteins secereted by synoviocytes, including hyaluronate.
All synovial joints are functionally classified as ____.
All synovial joints are functionally classified as diarthroses.
diarthrosis
A joint which permits free, unrestricted movement
Extrinsic ligament
Located outside the articular capsule of the joint it holds together.
Intrinsic ligament
Fused or incorporated into the articular capsule of the joint which it holds together.
Intracapsular ligament
Ligament which is located inside of the articular capsule of the joint it holds together.
Sagittal knee joint diagram
Articular disc
Fibrocartilagenous structure located inbetween articulating bones. Generally small and oval- or meniscus-shaped. May provide shock absorption.
Sometimes unites bones together and prevents movement, such as at the sternoclavicular joint or the distal radial-ulnar joint.
Bursa
Thin connective tissue filled with lubricating fluid. Located in regions where skin, ligaments, muscles, or muscle tendons can rub against each other, usually near a body joint. Classified based on location relative to the joint.
Subcutaneous bursa
Located between skin and underlying bone. Allows skin to move over bone smoothly.
Submuscular bursa
Found between muscle and underlying bone. Prevents rubbing of the muscle during movements.
Ex, the trochanteric bursa
Subtendinous bursa
Located between tendon and underlying bone.
Articular cartilage
Hypocellular, viscoelastic (due to water and proteoglycan) tissue that lines synovial joints. The articular surface is made of dense collagen of low proteoglycan content.
No basement membrane, innervation, or vascular supply.
During gentle walking, the force experienced by the hip joint is roughly equivalent to ___.
During gentle walking, the force experienced by the hip joint is roughly equivalent to 4 times the body weight of the individual.
What happens to the articular cartilage during loading?
Water exudes from proteoglycans and mixes with hyalonurate-rich synovial fluid.
The resulting coeffient of friction produced by this process is 1/5 that of the smooth ice-smooth ice coefficient of friction.
The integrity of the articular cartilage matrix is maintained by ___.
The integrity of the articular cartilage matrix is maintained by chondrocytes.
Articular cartilage is bound to the underlying bone through ____.
Articular cartilage is bound to the underlying bone through a narrow calcified zone of cartilage.
High loading of a healthy joint is unlikely alone to ____
High loading of a healthy joint is unlikely alone to initiate joint disease
Disuse of a joint leads to ___.
Prolonge ___ may even lead to ___.
Disuse of a joint leads to atrophy of the articular cartilage.
Prolonged atrophy may even lead to replacement of the articular cartilage with fibro-fatty tissue.
All connective tissues, including cartilage, respond to ___.
All connective tissues, including cartilage, respond to the mechanical forces placed upon them and, in general, extra use leads to hypertrophy and mechanical strengthening
Synovial membrane
1-3 cells thick. Forms the surface layer of the synovial tissue, but is otherwise not particularly distinct from it.
Deep synovial tissue is made up of . . .
- Many vascular vessels
- Many fat-rich cells
- Low cell count outside of a discontinuous layer of synovial intimal (aka synoviocytes) cells on the internal joint surfaces
- Synoviocytes line all surfaces apart from cartilage and menisci
- Aspiratable volume of only 0-4 mL of fluid
Changes in the loading-capability of one joint have effects on ___.
Changes in the loading-capability of one joint have effects on the loading-capability of other joints.
Hyaluronate
Produced by synoviocytes. Present in synovial fluid.
A linear, repeating disaccharide of β-D-gluconuryl-β-D-N-acetyl-glucosamine. Very high molecular weight, greater than 10 megadaltons.
Forms the central axis of the proteoglycan aggregates in synovial fluid which provides integrity to articular cartilage and other extracellular matrices of the synovium.
It is the main component responsible for synovial fluid’s visco-elastic properties.
How fluid accumulates in the synovium
The synovium has a high osmotic potential as a result of all of the proteins, proteoglycans, and carbohydrates secreted into it by synoviocytes.