Canine Joints Flashcards
What are joints?
The junction between bones
What are the 3 main categories according to characteristic structural features?
Fibrous joints
Cartilaginous joints
Synovial joints
Describe fibrous joints
Bones bound together by fibrous connective tissue
Limited movement, often only for a short time
Bones may eventually fuse
Describe cartilaginous joints
Bones united by fibrocartilage or hyaline cartilage
Generally allows more movement between attached bones than fibrous joints but less than synovial joints
Describe synovial joints
Freely movable joints, filled with synovial fluid
Where are the different types of fibrous joints?
Sutures
Gomphoses
Syndesmoses
Describe suture fibrous joints
Between bones of the skull
Allows bones to grow but fuse over time as growth ceases
Describe gomphoses
Attachment between tooth roots and tooth socket of the jaw
Describe syndesmoses
Joints with limited motion that are neither sutures nor gomphoses, at which bones are attached by fibrous connective tissues
Describe hyaline cartilage joints
Relatively immovable joint, usually temporary, with ossification over time
Attachments between rib and sternum are also hyaline cartilage, but cartilage remains for life
Describe fibrocartilaginous joints
Articulating surfaces joined by fibrocartilage, +/- a hyaline cartilage component
Joint may occasionally ossify
What are examples of fibrocatilaginous joints?
Pelvic and mandibular symphyses
Intervertebral disks
What is the most common joint?
Synovial joints
What are the basic features of synovial joints?
Joint capsule Articular cartilage Ligaments Tendons Sheaths Bursae
What are the layers of the joint capsule?
Fibrous and synovial layers
What does the synovial joint structure allow for?
Appropriate alignment of bones and joints
What is synovial fluid produced by? What does it do?
Synovial membrane
Bathes the articular surface
What does articular cartilage cover?
The ends of the long bones that articulate together to form synovial joint
What does normal articular cartilage do?
Absorbs concussion
Provides a nearly frictionless surface for bones that articulate together
What is articular cartilage composed of?
A water-rich gel that is anchored in place to the subchondral plate by looping arches of durable collagen fibers
What do chondrocytes do?
Maintain the proteoglycan gel and collagen loops
Why does synovial fluid have a high viscosity?
Hyaluronic acid
What lines the synovial membrane?
A-phagocytic and B-secretory synoviocytes
What do B-synoviocytes secrete?
Hyaluronic acid
