Joints, Synovial Fluid and Cartilage Flashcards
3 basic types of joints
Fibrous
Cartilaginous
Synovial
3 Fibrous joints
Periodontal Ligament
Cranial Sutures
Interosseus Membranes
2 types of cartilaginous joints
Primary and Secondary
Describe a Primary cartilaginous joint and give an example of one
Only hyaline cartilage
Growth plates
Describe a Secondary Cartilaginous joint and give an example of one
Hyaline AND fibrocartilage
Intervertebral Disc
Common features of a synovial joint
Articular Cartilage
Fibrous Capsule
Synovial Membrane
Synovial Cavity + Synovial fluid
What MAY synovial joint also contain
Articular Discs
Ligaments
Bursae
6 types of synovial joint and examples of each
Plane - Intervertebral Hinge - Elbow (proper name for joint) Pivot - ? Condylar (ellipsoid) - 1st vertebra? Saddle - Thumb? Ball and socket - Shoulder
What Glycoprotein, Proteoglycan and Glycosaminoglycan are related to hyaline cartilage
Glycoprotein - Lubricin
Proteoglycan - Aggrecan
Glycosaminoglycan - Hyaluronic Acid
What layer hyaline cartilage produces Lubricin
Superficial/Tangential layer
What layer of hyaline cartilage produces Aggrecan
Transitional layer
What structure produces Lubricin and Aggrecan
Lubricin - Flattened Chondrocytes
Aggrecan - Round Chondrocytes
What layer of hyaline cartilage produces Collagen
Superficial/Tangential layer
What changes from Superficial to Deep layer of Hyaline Cartilage
Orientation of collagen
What feature of cartilage makes supplying nutrients difficult and how is this overcome
It’s avascular
Synovial Fluid => Direct exchange of CO2 and metabolites between blood and synovial fluid
What produces Synovial Fluid
Synoviocytes
2 types of Synoviocytes
Type A
Type B
Describe Type A Synoviocytes
Look like Macrophages
Remove debris
CONTRIBUTE to synovial fluid production
Describe Type B Synoviocytes
Fibroblast like
MAIN producer of synovial fluid
What is synovial fluid composed of
Hyaluronic Acid and Lubricin (fluid component?water?)
Volume of synovial fluid in knee joint and turnover
~0.5ml
~2 hours
Functions of synovial fluid
Nutrition of cartilage
Removal of waste products
Lubrication => less friction => less wear
Describe the 3 methods of Lubrication
Boundary - Lubricin binds to receptors on ARTICULAR SURFACES forming a THIN FILM
Hydrodynamic - Surfaces kept apart by liquid pressure (like aquaplaning) (viscosity changes with load and velocity of movement)
Weeping
Describe the 3 methods of Lubrication
Boundary - Lubricin binds to receptors on ARTICULAR SURFACES forming a THIN FILM
Hydrodynamic - Surfaces kept apart by liquid pressure (like aquaplaning) (viscosity changes with load and velocity of movement)
Weeping - Fluid that present in the cartilage is squeezed out into the synovial cavity to increase fluid volume
What is a bursa and where is one found
Small fluid-filled sac lined by synovial membrane containing viscous synovial fluid
Provides a cushion between bones and tendons and/or muscles around a joint
Helps Reduce friction
can be found in the knee
What happens to Synovial cartilage as one ages
Viscosity of synovial fluid decreases => Reduced lubrication and slower joint movements
Water content of cartilage decreases => Reduced shock absorption
