1F Flashcards
Articular System
Joint or articulation, refers to the connections between components of the skeletal system.
Origin: Articulus
Latin;joint
Arthology
Study of joints.
Origin: Arthron
Greek;joint
Arthritis
Inflammation of joints.
Origin: Arthron
Greek;joint
Criteria for classification of joints
The nature of the intervening tissue.
ex. the tissue between the 2 articulating ends of the bones.
3 major types of joints
Fibrous (synarthroses), Cartilaginous (amphiarthroses), and Synovial (diarthroses)
Fibrous (synarthroses) Joint
A joint that is united by fibrous connective tissue.
Cartilaginous (amphiarthroses) Joint
A joint united by cartilage.
Synovial (diarthroses) Joint
Joint characterized by the possession of a cavity and specialized to permit free movement.
Intervening tissue is is synovial fluid.
SUTURE Fibrous Joint
Formed by 2 bones whose articulating surfaces are serrated.
ex. in the form of interdigitations
- It is immovable
- It is located only in the skull
ex. sagittal suture
SYNDESMOSES Fibrous Joint
A fibrous joint in which the intervening connective tissue is of greater amount than that found in a suture.
- It is slightly moveable.
- It is located between the 2 bones of the forearm and the 2 bones in the leg.
ex. radioulnar syndesmoses (in which the intervening connective tissue is the interosseous membrane).
HYALINE Cartilage Joint
A joint in which the intervening tissue is hyaline cartilage.
- It is immovable.
- Located between the epiphysis and diaphysis of growing bone (a temporary condition that will later ossify).
ex. epiphyseal disc
FIBROCARTILAGE Joint
A joint which the intervening tissue is fibrocartilage.
- It is slightly moveable.
- Locations
ex. between adjacent vertebral bodies: intervertebral discs
ex. between the right and left pubic bones: interpubic disc
ARTICULAR CARTILAGE Synovial Joint
Cover the ends of articulating bones.
- Layer of hyaline cartilage.
- It is avascular.
- It lacks nerves.
- It is radiolucent (cannot be seen on radiographs).
ARTICULAR CAPSULE Synovial Joint
Encapsulates the joint; connects together the 2 bones and completely encircles the joint, thus enclosing the synovial cavity.
- Composed of 2 layers.
- An outer fibrous layer that is continuous with the periosteum of bone.
- An inner layer that is called synovial membrane that lines the inside of the fibrous layer; quite vascular and produces the synovial fluid that fills the synovial cavity, and lubricates the joint and nourishes the articular cartilage.
- The synovial fluid is derived from blood.
Movements at synovial joints
Gliding, angular, rotation
Gliding Movement
Involve a slight slipping of 1 bone over another, usually flat surfaces; little actual movements occur.
Angular Movements
Flexion, extension, abduction, adduction, circumduction
of foot and joint: dorsiflexion, plantar flexion, eversion, inversion
Flexion
Bending of a joint so that the angle becomes more acute.
Extension
Straightening of a flexed joint.
Abduction
Movement in a frontal plane away from the median plane.
Adduction
Movement in a frontal plane toward the median plane.
Circumduction
Combination of the above 4 movements.
Dorsiflexion
Moving the dorsum of the foot toward the anterior leg.