Joints and their connective tissues Flashcards
what are joints?
where 2 bones meet and articulate
structure of a joint allows?
mobility and overall stability
the 2 classifications of joints are?
structural: can be fibrous, cartilaginous, synovial.
Functional: (focused on movement) can be synarthroses, amphiarthroses, diathroses
what does synarthroses mean
immovable joints
what does amphiarthroes mean
slightly movable joints
what does diarthroses mean
freely movable joints
describe fibrous joints. Give 3 examples
have dense regular CT, no cartilage. no joint cavity. it is fixed or scarcely movable. sutures, syndesmoses, gomphoses
describe sutures
Mainly in the skull. The bones is coved by a layer of osteogenic cells called CAMBIAL, and covered by a fibrous tissue continuous with the periosteum called capsular lamella. there is a loose CT in between
what are syndesmoses?
bones connected by only ligaments, whose movements depend on length of the fibers (its a fibrous connection)
what are gomphoses?
ligament is a short periodontal ligament
describe cartilaginous joints
the bone connection is made of cartilage, no joint cavity, slightly movable, there are 2 types (synchondrosis, symphysis)
what is a Synchondroses?
is a cartilgenous joint made of non-articular hyaline cartilage. It tends to synostose with age
give an example of synchondroses?
epiphyseal plates, and joint between first costal cartilage and manubrium
what is a symphysis joint? Give 2 examples
the ends of the articulating bones are covered by hyaline cartilage but a disc of fibrocartilage connects the bones. Pubic symphysis and intervertebral discs
describe synovial joints
the bones are not directly joined, there is a joint cavity, highly movable, there are 6 types: plane/gliding/hinge/pivot/condyloid/saddle/ball and socket
what are 5 characteristics of synovial joints?
hyaline cartilage present, fibrous capsule present, synovial membrane present, fibrocartilagenous structures also present, joint stability is provided by ligaments and tendons
what is the general structure of articular surfaces
have an irregular shape, covered by articular hyaline cartilage which can be permanent(deep coating) or transient(superficial coating near cavity)
what is the general structure of a fibrous capsule?
it is attached to the whole circumference of the bone tip, it entirely surrounds the articulation. It is made of dense irregular CT. Can be intrinsic or extrinsic, inner surface is completely covered by synovial membrane
function of articular cartilage?
to absorb shock and reduce friction during movement
what is the general structure of a synovial membrane? (visually)
pink/smooth/small villi/secretes synovial fluid/dynamic changes in shape during movement/may protrude through capsule fibrous bundles forming bursae and tendon sheets
name a few microscopic aspects of synovial membranes
has an intima (granular amorphous fiber-free matrix embedding packed synovial cells. Has subsynovial tissue (a fibrovascular layer, lamella of collagen and elastin, small fat lobules surrounded by highly vascularized septa, aspecific cell types)
what is the general structure of fibrocartilagineous joints?
A fat pad, a disc or meniscus, labrum (additionally there is also tendons, accessory ligaments, bursae)
what is a tendon sheath?
cylinders of CT lined with synovial membrane and wrapped around a tendon
describe plane/gliding joints and give examples
are uniaxial, limited rotation is possible. Intervertebral, intercarpal
describe saddle joints and give examples
are biaxial, thumb, intercarpal
describe hinge joints
monoaxial, convex cylinder in one bone, corresponding concavity in other bone, elbow ankle interpharyngeal
describe pivot joints
monoaxial, rotation around a single axis, cylindrical bone process rotating within a circle of bone and ligament, articulation between dens and atlas
describe ball and socket joints
smooth hemispherical head fits within a cuplike depression, multiaxial, shoulder and hip joints
describe condyloid joint
oval convex surface on one bone fits into a similarly shaped depression on other bone, atlantooccipital
what are ligaments?
they hold joints together, guide movement, they can tear and cause the joint to dislocate
what are ligaments made of?
dense CT which are sparcely vascularized, 20% fibroblasts, 80% extracellular cells– 70% water and 30% collagen, elastin
