Week 2 - Joints Flashcards
Name all the types of joints
- synovial joints
- syndesmosis
- synchondrosis
- synostosis
- symphysis
- gomphosis
What is a synovial joint and where is it found?
Joint with two opposing surfaces covered by cartilage, bathed in synovial fluid within a joint capsule
- found in most appendicular joints
- posterior joints of spine
What is a syndesmosis and where is it found?
Joint where two bones are joined by fibrous tissue only.
- found in skull sutures
- found between distal end of tibia and fibula
What is a synchondrosis and where is it found?
Two bones are joined by cartilage.
- found in physis (joins epiphysis & metaphysis)
What is a synostosis and where is it found?
Bones are fused together obliterating joint.
- found in bones of the pelvis
What is a symphysis and where is it found?
Two bones joined by cartilage but with no synovial fluid (and therefore very little movement).
- found at symphysis pubis
- found between vertebrae
What is a gomphosis and where is it found?
Fibrous connection between a tooth and its socket. Blood vessels and nerves cross the joint
When do synovial joints begin to develop?
At 6-9 weeks in development.
Which develops first: upper or lower extremity?
upper extremity
What are the 4 stages of joint development?
- Homogenous Interzone
- Three-layer interzone
- Early liquefaction of middle layer
- Full separation and joint cavitation
What is found in the homogenous interzone of developing bone?
Mesenchymal cells
What will the mesenchymal interzone develop into?
- articular cartilage
- meniscus
- cruciate ligaments
- collateral ligaments
(these happen before development of synovial fluid
What is found in the three-layered interzone?
- two layers of densely packed cells (become articular surfaces).
- one layer of loosely packed undifferentiated cells in between the dense layers.
What is the tiny sesamoid bone located BEHIND the knee called?
flabella
What are the layers of the synovium?
- briefly decribe each
Outer: rich supply of blood vessels, nerves, and lymph
Inner: thin syncytium
What cells are found in the inner layer of the synovial membrane?
Type A –> cells specialized to clear waste material
Type B –> cells specialized to synthesize hyaluronic acid
What is synovial fluid composed of?
dialyzed plasma with glycoprotein and hyaluronic acid
Approximately how much synovial fluid would you find in the knee?
~5 cubic cm
What is the joint capsule?
tough fibrous tissue that joins the two bones of a joint
What is a bone bruise?
Injury to the subchondral bone
Name a couple examples of tendons that are intra articular.
Biceps; popliteus
What happens when a joint is injured?
- injury (twist/fall/etc)
- inflammation (redness, swelling, pain, heat)
- effusion (increase in joint fluid volume)
- healing/resolution
What is immediate joint swelling after an injury indicative of?
hemarthrosis
- -> fracture
- -> significant ligament/capsular injury
What is development of a bruise indicative of?
bleeding into subdermal tissue
