A&P 8: Joints Flashcards
Joints
Articulations; sites where 2 or more bones meet
Synarthroses
immovable joints
Amphiarthroses
slightly movable joints
Diarthroses
freely movable joints
Fibrous joints
bones joined by fibrous tissue, namely dense fibrous connective tissue; no joint cavity present; 3 types - sutures, syndesmoses, gomphoses
Sutures
“seams”; occur only between bones of the skull
Synostoses
closed sutures; “bony junctions”
Syndesmoses
bones connected exclusively by ligaments, cords or bands of fibrous tissue
Gomphosis
peg-in-socket fibrous joint; only example is the articulation of a tooth with its bony alveolar socket; “nail” or “bolt”
Periodontal ligament
fibrous connection in the case of a tooth in its socket
Cartilaginous joints
articulating bones united by cartilage; lack a joint cavity; not highly movable; 2 types - synchondroses & symphyses
Synchondrosis
junction of cartilage; a bar or plate of hyaline cartilage unites the bones; virtually all of these are synarthrotic
Symphysis
a joint where fibrocartilage unites the bone; “growing together”; limited movement permitted
Synovial joints
“joint eggs”; articulating bones are separated by a fluid-containing joint cavity; substantial freedom of movement
Articular cartilage
glassy-smooth hyaline cartilage covers the opposing bone surfaces; keep bone ends from being crushed
Articular capsule
2-layered joint capsule
Fibrous layer
tough external layer of an articular capsule; composed of dense irregular connective tissue that is continuous with the periostea of the articulating bones; strengthens the joint so the bones are not pulled apart
Synovial membrane
inner layer of an articular capsule; composed of loose connective tissue; covers all internal joint surfaces that are not hyaline cartilage; function: make synovial fluid
Synovial fluid
small amount of this slippery fluid occupies all free spaces within the joint capsule; derived largely by filtration from blood flowing through capillaries in the synovial membrane; has a viscous, egg-white consistency
Ligaments
synovial joints are reinforced and strengthened by a number of bandlike _____
Capsular ligaments
thickened parts of the fibrous layer
Extracapsular ligaments
distinct; ligaments found outside the capsule
Intracapsular ligaments
ligaments found deep to the capsule; covered with synovial membrane; do not actually lie within the joint cavity
Fatty pads
cushioning between the fibrous layer and the synovial membraneor bone