Joints

1. Joints

2. Joints (articulation) • Defined: A point of contact between bones, between cartilage and bones, or between teeth and bones. • When two bones articulate with one another we say that the 2 bones form a joint. • Arthrology = study of joints • Kinesiology = study of movement within the human body • Rheumatology = study of joint diseases and related conditions

3. Joint Strength, Flexibility, & Movement • Determined by: • Shape of the articulating bones • Flexibility of the ligaments that attach bone to bone • Tension of tendons and muscles of the articulating bones • Hormones • Dislocation: When articulating bones move from their normal positions.

4. Joint Structure • Classification: • Type of connective tissue that holds the bones together. • The presence or absence of a synovial cavity (space between the articulating bones).

5. Joint Function • Classification: • Relates to the amount of movement allowed • Types: • Synarthrosis = Immoveable joint • Ex. pelvis , sutures, teeth • Amphiarthrosis= Slightly moveable joint • Ex. epiphysis, tibia-fibula, vertebrae and pelvic symphysis • Diarthrosis = A freely movable joint. • All synovial joints fall into this category • Come in many shapes • Allow for different types of movements

6. Types of Fibrous Joints • Fibrous joints are held together by fibrous connective tissue – bones lack a synovial cavity = little to no movement. • Suture • Unite the bones of the skull • The irregular interlocking edges decrease chances of fracturing • Immovable = ?

7. Types of Fibrous Joints 2. Syndesmosis • The articulating bones and the amount of dense fibrous connective tissue is greater than in sutures. • Slight movement = ? • Ex. The distal articulation between the tibia and the fibula.

8. Types of Fibrous Joints 3. Gomphosis • Cone shaped peg that fits into a socket • The only ones are found in the articulations of the roots of the teeth with the sockets of the aveolar processes of the mandible & maxillae. • Immovable = ?