Joints and synovial fluid Flashcards
What are the 3 main types of joints?
Fibrous
Cartilaginous
Synovial
What are the 3 types of fibrous joints?
Suture
Syndesmosis
Gomphosis
What are the 2 types of cartilaginous joints?
Synchondrosis
Symphysis
What are the 6 types of synovial joints?
Saddle Hinge Plane Condylar Ball and socket Pivot
What is an example of a synchondrosis?
Epiphyseal growth plate
What is an example of a symphysis?
Vertebral discs
Pubic symphysis
What is typically found in a synovial joint?
Fluid filled synovial cavity
Articular cartilage
Fibrous capsule
Synovial membrane
Give an example of a synovial plane joint
Intervertebral joints
Give an example of a synovial hinge joint
Elbow joint
Give an example of a synovial pivot joint
Radio-ulnar joint
Give an example of a synovial condylar joint
The atlanto-occipital joint (atlas to skull)
Give an example of a synovial saddle joint
The thumb joint
Give an example of a synovial ball and socket
Glenohumeral joint
What can improve joint stability?
Shape of articulating surfaces
Capsule and ligaments
Muscles
What is the superficial layer of the articular cartilage?
Flattened chondrocytes that produce collagen and glycoproteins
What is the transitional layer of articular cartilage?
Round chondrocytes producing proteoglycans
What are glycoproteins?
Proteins which have oligosaccharides attached - more protein than carbohydrate
What are proteoglycans?
Heavily glycosylated proteins - More carb than protein
What are Glycosaminoglycans?
Long unbranched polysaccharides which are highly polar and attract water
Where is synovial fluid produced?
The synovial membrane/synovium
What cells produce synovial fluid?
Synoviocytes
How does the cartilage in synovial joints get nutrients with no vasculature?
There is a direct exchange of oxygen, carbon dioxide and metabolites between the blood and synovial fluid
What are the 2 types of synoviocytes?
Type A and Type B
What is the function of type A synoviocytes?
To remove debris and some role in synovial fluid production
What is the function of type B synoviocytes?
The main producer of synovial fluid
What is synovial fluid made up of?
Hyaluronic acid
Lubricin
Fluid from plasma
What is the turnover of synovial fluid?
Around 2 hours
What are the functions of synovial fluid?
Nutrition of cartilage
Removal of waste
Lubrication to reduce friction and wear
How does synovial fluid provide lubrication?
Glycoproteins like lubricin bind to receptors on articular surfaces to form a thin film
Surfaces are kept apart by liquid pressure
Fluid present in cartilage is squeezed into the synovial cavity to increase fluid volume
What happens to synovial joints as people age?
Viscosity of fluid increases resulting in slower movements and reduced lubrication
Water content of cartilage decreases reducing shock absorption
