What is the difference between a cartilaginous and synovial joint

Synovial cavities are filled with synovial fluid. The knees and elbows are examples of synovial joints. Joints or articulations connections between bones can be classified in a number of ways. The primary classifications are structural and functional. Functional classification is based on the type and degree of movement permitted. Types of Synovial Joints. Privacy Policy. Skip to main content.

Search for:. Classification of Joints. Structural Classification of Joints There are three structural classifications of joints: fibrous, cartilaginous, and synovial.

Learning Objectives Describe the three structural categories of joints. Key Takeaways Key Points The type and characteristics of a given joint determine the degree and type of movement. Structural classification categorizes joints based on the type of tissue involved in their formations.

A uniaxial joint only allows for a motion in a single plane around a single axis. The elbow joint, which only allows for bending or straightening, is an example of a uniaxial joint. A biaxial joint allows for motions within two planes. An example of a biaxial joint is a metacarpophalangeal joint knuckle joint of the hand. The joint allows for movement along one axis to produce bending or straightening of the finger, and movement along a second axis, which allows for spreading of the fingers away from each other and bringing them together.

A joint that allows for the several directions of movement is called a multiaxial joint sometimes called polyaxial or triaxial joint. This type of diarthrotic joint allows for movement along three axes Figure 9. The shoulder and hip joints are multiaxial joints. They allow the upper or lower limb to move in an anterior-posterior direction and a medial-lateral direction. In addition, the limb can also be rotated around its long axis.

This third movement results in rotation of the limb so that its anterior surface is moved either toward or away from the midline of the body. Structural classifications of the body joints are based on how the bones are held together and articulate with each other. At fibrous joints, the adjacent bones are directly united to each other by fibrous connective tissue. Similarly, at a cartilaginous joint, the adjacent bones are united by cartilage. In contrast, at a synovial joint, the articulating bone surfaces are not directly united to each other, but come together at a fluid-filled joint cavity.

The functional classification of body joints is based on the degree of movement found at each joint. A synarthrosis is a joint that is essentially immobile. This type of joint provides for a strong connection between the adjacent bones, which serves to protect internal structures such as the brain or heart.

Examples include the fibrous joints of the skull sutures and the cartilaginous epiphyseal plate. A joint that allows for limited movement is an amphiarthrosis. An example is the pubic symphysis of the pelvis, the cartilaginous joint that strongly unites the right and left hip bones of the pelvis. The cartilaginous joints in which vertebrae are united by intervertebral discs provide for small movements between the adjacent vertebrae and are also amphiarthrotic joints. Synchondroses are found in the epiphyseal plates of growing bones in children.

In symphyses, hyaline cartilage covers the end of the bone, but the connection between bones occurs through fibrocartilage. Symphyses are found at the joints between vertebrae and between the pubic bones. Amphiarthroses allow only slight movement; therefore, either type of cartilaginous joint is an amphiarthrosis. Synovial joints are the only joints that have a space between the adjoining bones. This space, referred to as the synovial or joint cavity, is filled with synovial fluid.

Synovial fluid lubricates the joint, reducing friction between the bones and allowing for greater movement. The ends of the bones are covered with articular cartilage, a hyaline cartilage. The entire joint is surrounded by an articular capsule composed of connective tissue. This allows movement of the joint as well as resistance to dislocation.

Articular capsules may also possess ligaments that hold the bones together. Synovial joints are capable of the greatest movement of the three structural joint types; however, the more mobile a joint, the weaker the joint.

Knees, elbows, and shoulders are examples of synovial joints. Since they allow for free movement, synovial joints are classified as diarthroses. Synovial joints allow for many types of movement including gliding, angular, rotational, and special movements.

The range of movement allowed by synovial joints is fairly wide. These movements can be classified as: gliding, angular, rotational, or special movement. Gliding movements occur as relatively flat bone surfaces move past each other. They produce very little rotation or angular movement of the bones. The joints of the carpal and tarsal bones are examples of joints that produce gliding movements. Angular movements are produced by changing the angle between the bones of a joint.

There are several different types of angular movements, including flexion, extension, hyperextension, abduction, adduction, and circumduction. Flexion, or bending, occurs when the angle between the bones decreases. Moving the forearm upward at the elbow or moving the wrist to move the hand toward the forearm are examples of flexion. In extension, the opposite of flexion, the angle between the bones of a joint increases.

Straightening a limb after flexion is an example of extension. Extension past the normal anatomical position is referred to as hyperextension. This includes moving the neck back to look upward or bending the wrist so that the hand moves away from the forearm. Abduction occurs when a bone moves away from the midline of the body.

Examples of abduction include moving the arms or legs laterally to lift them straight out to the side. Adduction is the movement of a bone toward the midline of the body. Movement of the limbs inward after abduction is an example of adduction. Circumduction is the movement of a limb in a circular motion, as in swinging an arm around. Angular and rotational movements : Synovial joints give the body many ways in which to move.

These movements take place at the shoulder, hip, elbow, knee, wrist, metacarpophalangeal, metatarsophalangeal, and interphalangeal joints. Moving the limb or hand laterally away from the body, or spreading the fingers or toes, is abduction. Adduction brings the limb or hand toward or across the midline of the body or brings the fingers or toes together.

Circumduction is the movement of the limb, hand, or fingers in a circular pattern, using the sequential combination of flexion, adduction, extension, and abduction motions. Medial and lateral rotation of the upper limb at the shoulder or lower limb at the hip involves turning the anterior surface of the limb toward the midline of the body medial or internal rotation or away from the midline lateral or external rotation.

Rotational movement is the movement of a bone as it rotates around its longitudinal axis. Rotation can be toward the midline of the body, which is referred to as medial rotation, or away from the midline of the body, which is referred to as lateral rotation.

Movement of the head from side to side is an example of rotation. Some movements that cannot be classified as gliding, angular, or rotational are called special movements.

Inversion involves moving the soles of the feet inward, toward the midline of the body. Eversion, the opposite of inversion, involves moving of the sole of the foot outward, away from the midline of the body. Protraction is the anterior movement of a bone in the horizontal plane. One example is the joint between the first pair of ribs and the sternum. This type of joint allows for some movement. The hip bones, connected by the pubic symphysis, and the vertebrae, connected by intervertebral discs, are two examples of symphyses.

Synovial Joints. Synovial joints are characterized by the presence of an articular capsule between the two joined bones. Bone surfaces at synovial joints are protected by a coating of articular cartilage. Synovial joints are often supported and reinforced by surrounding ligaments, which limit movement to prevent injury.

There are six types of synovial joints:. Major gliding joints include the intervertebral joints and the bones of the wrists and ankles. These joints allow for flexion and extension. Major hinge joints include the elbow and finger joints.

At the top of the spine, the atlas and axis form a pivot joint that allows for rotation of the head. The wrist joint between the radius and the carpal bones is an example of a condyloid joint.