Joint Types, Movements, and Stability - Anatomy and Physiology
- Which type of synovial joint is the joint between the dens of the axis and the atlas?
- A pivot joint. The atlas rotates around the dens, turning the head from side to side.
- Classify the pubic symphysis structurally and functionally.
- A cartilaginous joint (symphysis) joined by a fibrocartilage pad; functionally it is an amphiarthrosis.
- Which type of synovial joint is the carpometacarpal joint of the thumb?
- A saddle joint. Its concave-convex surfaces allow flexion, extension, abduction, adduction and opposition.
- What type of joint is an epiphyseal plate joining epiphysis and diaphysis?
- A synchondrosis: a cartilaginous joint of hyaline cartilage that is immovable and is replaced by bone after growth ends.
- What is the main function of the anterior cruciate ligament of the knee?
- It prevents the tibia from sliding anteriorly on the femur and helps prevent knee hyperextension.
- Which three factors mainly determine the stability of a synovial joint?
- The shape of the articular surfaces, the number and position of ligaments, and the tone of muscles whose tendons cross the joint.
- Starting in anatomical position, turning the palm to face posteriorly is which movement?
- Pronation. The radius rotates and crosses over the ulna; supination returns the palm to face anteriorly.
- What are the three functional classes of joints, from least to most movable?
- Synarthrosis (immovable), amphiarthrosis (slightly movable) and diarthrosis (freely movable).
- What type of fibrous joint anchors a tooth in its bony socket?
- A gomphosis. The periodontal ligament holds the tooth in the alveolar socket.
- Which type of synovial joint is the shoulder (glenohumeral) joint?
- A ball-and-socket joint. Its shallow glenoid cavity allows great mobility but makes it less stable than the hip.
- What are the three structural classes of joints?
- Fibrous, cartilaginous and synovial. They are classified by the material joining the bones and whether a joint cavity is present.
- Classify the sutures between adult skull bones structurally and functionally.
- Fibrous joints that are synarthroses. Short connective tissue fibers lock the bones so they are immovable.