Synovial (True) Joints Flashcards
Hoe can joints be classified?
- number of bones involved in a joint
- the degree of movement possible
- the form of the joint surfaces
What are the three common features that all synovial joints share? In Latin?
- joint capsule (capsula articularis)
- joint cavity (cavum articularis)
- hyaline joint cartilage (cartiligo articularis)
How do you say “joint” in Latin?
articularis
What is the name for the hyaline joint cartilage in Latin? What does it do?
hyaline joint cartilage = cartilago articularis
- it covers the end of the two or more bones forming the joint
What two layers is the joint capsule composed of? And in Latin?
- the outer fibrous layer (stratum fibrosum)
- inner layer: synovial membrane (stratum synoviale)
What does the structure and thickness of the outer fibrous layer depend on? What is its Latin name?
- stratum fibrosum
- depends on the mechanical load placed in the area
What can the fibrous layer contain? What is its Latin name?
- capsule ligaments
- stratum fibrosum
What is the purpose of the synovial inner membrane? What is its Latin name?
- stratum synoviale
- lines the joint cavity and is supplied with cells, blood vessels, and nerves
What does the synovial membrane appear as (colour)? What is its Latin name?
- stratum synoviale
- ivory colour with a slight yellow tinge
What kind of accessories does the synovial membrane contain? Latin names?
- synovial villi (villi synoviales)
- synovial folds (plicae synoviales)
How do you say “synovial folds” in Latin?
plicae synoviales
What further subdivisions does the synovial membrane have?
1) Inner synoviocytes layer- intima synovialis (comprised of cover cells, the synoviocytes)
2) subsynovial layer- startum subsynoviale
What two types of cells exist in the inner synoviocytes layer? Latin name? What are they responsible for?
1) type-A synoviocytes (responsible for phagocytosis)
2) type-B synoviocytes (produce and secrete proteins)
What are joints filled up with? What colour? What function?
- synovial fluid
- pale yellow, viscous fluid
- primary purpose: lubricate the joint, reducing friction between articular surfaces
What else, apart from synovial joints, does synovial fluid fill?
tendon sheaths (is found in tendon bursae)
Why does hydrarthrosis ocuur?
due to the increased production of synovia
What is synovial fluid composed of?
hyaluronic acid, sugar, electrolytes, enzymes
- involved in nutrient supply of cartilage
What are “free joint bodies”? What is a different name?
- “joint mice”
- free-swimming intraarticular pieces of cartilage or bone resulting from a chip fracture of ossification of synovial villi.
What is joint cartilage? Where is it thick? Where is it thin, thick? What is it attached to?
thin- concave joint
thick- convex joint
it is attached to a thin subchondral bone layer.
What does the hyaline cartilage matrix do?
- absorbs shock,
- is flexible, possesses viscoelastic properties
What does joint cartilage lack?
nerves, blood vessels (with a few exceptions).
How is articular cartilage divided?
1) superficial zone
2) intermediate zone
3) radial zone
4) calcified zone
What is the superficial zone of articular cartilage made out of?
tightly woven collagen fibres
What is the radial zone of articular cartilage made out of?
cartilage fibres that unite to form radially organised bundles
What is the function of the calcified zone of the articular cartilage?
this structure guarantees a strong attachment of the cartilage to the bone structure.
What lies beneath the joint cartilage?
the subchondral bone plate
What is the metabolism of joint cartilage?
anaerobic
How is cartilage supplied with nutrients?
MAIN: diffusion
SIDE: blood vessels of the bone marrow
What are joints strengthened by? In Latin?
capsular joint LIGAMENTS (ligamenta articularia)
How are joints classified depending on the number of bones involved in the joint?
1) SIMPLE JOINTS (2 bones only)
2) COMPOSITE JOINTS (2+ bones)
How are joints classified depending on the degree of possible movement?
1) UNIAXIAL JOINTS (hinge and vivot joint)
2) BIAXIAL JOINTS (saddle and ellipsoidal joint)
3) MULTIAXIAL JOINTS (ball and socket and and spheroidal joint)
4) TIGHT JOINTS (sacroiliac joint)
What is a different name for the ball and socket joint?
spheroidal joint
What is the cotyloid joint?
a socket joint where the cavity covers more than half of the ball.
What is the ellipsoid joint? What is its different name?
an oval ball and socket joint.
- condylar joint
What is the saddle joint?
opposing surfaces are reciprocally concave and convex.
What is the plane joint?
gliding joint
