Joint Classification Flashcards
Classification, Levers, Receptors
Synarthroses (Fibrous Joints)
Suture - e.g., sagittal suture of the skull
Syndesmosis - e.g., tibia and fibula with interosseous membrane
Gomphosis - e.g., tooth in its socket
Definition: Synarthroses (Fibrous Joints)
Fibrous joints composed of bones that are united by fibrous tissue and are NONSYNOVIAL. Movement is minimal to none with the amount of movement permitted at the joint dependent on the length of the fibers uniting the bones
Definition: Suture
Synarthroses
Union of 2 bones by a ligament or membrane
Immovable Joint
Eventual fusion is termed Synostosis
Definition: Syndesmosis
Synarthroses
Bone connected to bone by a dense fibrous membrane or cord
Very little motion
Definition: Gomphosis
Synarthroses
Two bony surfaces connect as a peg in a hole
The teeth and corresponding sockets in the mandible/maxilla are the only gomphosis joints in the body
The periodontal membrane is the fibrous component of the joint
Amphiarthroses (Cartilaginous Joints)
Synchondrosis - e.g., sternum and true rib articulation
Symphysis - e.g., pubic symphysis
Definition: Amphiarthroses (Cartilaginous Joints)
Cartilaginous joints have hyaline cartilage or fibrocartilage that connects one bone to another. These are slightly moveable joints
Definition: Synchondrosis
Amphiarthroses
Hyaline Cartilage
Cartilage adjoins 2 ossifying centers of bone
Provides stability during growth
May ossify to synostosis once growth is completed
Slight motion
Definition: Symphysis
Amphiarthroses
Generally located at the midline of the body
Two bones covered with hyaline cartilage
Two bones connected by fibrocartilage
Slight motion
Diarthroses (Synovial Joints)
- Uniaxial Joint - Hinge, e.g., elbow joint; Pivot, e.g., atlantoaxial joint
- Biaxial Joint - Condyloid, e.g., metacarpophalangeal joint of a finger; Saddle, e.g., carpometacarpal joint of the thumb
- Multi-axial joint - Plane (gliding), e.g., carpal joints; Ball and Socket, e.g., hip joint
Definition: Synovial Joints (Diarthroses)
Provide free movement between the bones they join. They have 5 distinguishing characteristics:
1) Joint cavity
2) Articular cartilage
3) Synovial membrane
4) Synovial fluid
5) Fibrous capsule
They are the most complex and vulnerable to injury
Definition: Uniaxial
One motion around a single axis in one plane of the body. (Hinge, Pivot)
Definition: Biaxial
Movement occurs in 2 planes and around 2 axes through the convex/concave surfaces. (Condyloid, Saddle)
Definition: Multi-axial
Movement occurs in 3 planes and around 3 axes. (Plane/gliding, Ball-and-socket)
Definition: Fulcrum
Axis of Rotation
