An Articulation is
Where two or more bones meet
Structural classification of joints
Fibrous
Cartilaginous
Synovial
Fibrous joint are held together by
collagen fibers
Physical thing that holds the bones together
Cartilaginous joints are held together by
Held together by cartilage
Synovial joints are held together by
a joint capsule (space between your bones)
Functional classification of joints
Amount of movement at the joint
Synarthroses
Amphiarthroses
Diarthroses
Synarthroses allow
No movement allowed
Amphiarthroses allow
Allow slight movement
Diarthroses allow
Freely moveable joints
Diarthroses, Amphiarthroses, Synarthroses are all
Synovial joints
3 Fibrous joints are
Sutures
Syndesmosis
Gomphoses
Sutures are
Where bones have fused together, your suture lines are formed by fibers and are not movable so they are synarthrotic in adults
Attributes of Syndesmosis
Held together by ligaments
Are fibrous because made of collagen fibers
Slight movement so they are amphiarthrotic
Attributes of Gomphoses
Joints between the teeth and the alveolar socket
Connected by periodontal ligament
Types of Cartilaginous joints
Synchondroses
Symphyses:
Synchondroses are connected by
hyaline cartilage and do not move
Symphyses are connected by
fibrocartilage and allow slight movement
Example of Synchondroses
epiphyseal plate and costal cartilages
Example of Symphyses
pubic symphysis and intervertebral discs
Most of this in our body
Synovial joints
Synovial joints are
All diarthroses
Articulating bones are separated by
a fluid-containing joint cavity
Characteristics of synovial joints
Joint articular capsule Synovial fluid Articular cartilage Reinforcing ligaments Joint cavity
Joint articular capsule
Surrounds the space holding the bones together
Synovial fluid function
Lubricates joints
Fills the joint cavity
Articular cartilage is
Hyaline cartilage covering the epiphyses
Reinforcing ligaments are
Syndesmoses
Allow a little of movement
And help out synovial joints as well
Joint cavities are
space between the bones
Optional friction-reducing structures
Bursae
Tendon sheath
Fatty pads
Menisci
Bursae
Synovial fluid filled sac
Tendon sheath
Fluid filled pouch surrounding a tendon
Still contains some synovial fluid
Fatty pads
Adipose tissue within certain joints that help to protect against compression and friction as there’s movement at the joint
Menisci
Help cushion knee joint
Fibrocartilage pads
Stability of synovial joints
Articular surfaces
Ligaments
Muscle tone
Articular surfaces
How well the bones fit together - the shape
Stable: head of femur into coxal bone (acetabelum)
Unstable: glenoid fossa and head of humerus
Attributes Ligaments
Help hold bones together
The less stability the more ligaments
The greater the range of motion of the joint the weaker it becomes
Muscle tone
Tendons can slightly contribute to joint stability when you contract the muscles