As with most other joints, synovial joints achieve movement at the point of contact of the articulating. The pivot joint, also known as rotary joint, allows for rotational movement. Saddle Joint At a saddle joint, both of the articulating surfaces for the bones have a saddle shape, which is concave in one direction and convex in the other see c. However, often the resulting additional synovial fluid will end up in the joint space, causing swelling. Synovial Membrane Also called a synovium or a stratum synovial, the synovial membrane is a very specialized connective tissue lining the inner surface of the capsules found in synovial joints and tendon sheaths. An example is the joint between the proximal elbow end of the radius and ulna bones of the forearm, which must rotate around one another, producing supination or pronation.
A healthy articular cartilage tolerates intensive and repetitive physical stress, but surprisingly it cannot self-heal or repair, even with the most minor injury. Amphiarthrosis An amphiarthrosis is a joint that has limited mobility. An axis in anatomy is described as the movements in reference to the three anatomical planes: transverse, frontal, and sagittal. Synovial joints are further sub-classified depending upon shape or joint movement: i. Indirect joint support is provided by the muscles and their tendons that act across a joint.
Usually only one or a few joints are affected, such as the big toe, knee, or ankle. An example is the manubriosternal joint or the joints between the skull bones surrounding the brain. Synovial joints are capable of the greatest movement of the three structural joint types; however, the more mobile a joint, the weaker the joint. The knuckle metacarpophalangeal joints of the hand between the distal end of a metacarpal bone and the proximal phalanx bone are condyloid joints. Based only on their shape, plane joints can allow multiple movements, including rotation. Subcutaneous bursae prevent friction between the skin and an underlying bone, submuscular bursae protect muscles from rubbing against a bone or another muscle, and a subtendinous bursa prevents friction between bone and a muscle tendon. Gout occurs when the body makes too much uric acid or the kidneys do not properly excrete it.
Goss Hinge Joints In hinge joints, the slightly rounded end of one bone fits into the slightly hollow end of the other bone. Circumduction is the movement of a limb in a circular motion, as in swinging an arm around. Toxic synovitis usually affects only one hip, although it is possible for inflammation and swelling to spread to other joints. 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.
More details on the skeletal system, which can help demonstrate the synovial joints, can be found. There are strong collateral ligaments to provide stability to the joint. The stifle joint, like most other articulations, are fixed by extracapsular ligaments, which in this case are the lateral and medial collateral ligaments. Their role is to reduce friction that can occur with movement, such as when tendons rub over bones. Condyloid joints are found where the shallow depression of one bone receives a rounded bony area formed by one or two bones.
Examples of ball-and-socket joints are the shoulder and hip joints Figure 7. However, ball-and-socket joints allow for large movements, while the motions between bones at a plane joint are small. Universal movement is allowed that is, in all axes and planes, including rotation. This arrangement permits substantial freedom of movement, and all synovial joints are freely movable diarthroses , they are the most structurally complex type of joints and are the most likely to develop uncomfortable and crippling dysfunction. Which type of synovial joint allows for the widest range of motion? Which type of synovial joint allows for the widest ranges of motion? Articular discs improve the fit between articulating bone ends, making the joint more stable and minimizing wear and tear on the joint surfaces.
These may be located outside of the articular capsule extrinsic ligaments , incorporated or fused to the wall of the articular capsule intrinsic ligaments , or found inside of the articular capsule intracapsular ligaments. The synovial fold is attached to the articular capsule. Arthrography, a type of medical imaging of joints, uses a contrast agent, such as a dye, that is opaque to X-rays. Spheroidal Joint The spheroidal joint is a type of. Occasionally, the adipose tissue found in the base of the solid preceding paragraph and fatty types of synovial folds passes through the ligamentum flavum and becomes continuous with the epidural adipose tissue of the vertebral canal Schulte et al.
It supplies the capsule, synovial membrane and the epiphyses. Arthritis is a common disorder of synovial joints that involves inflammation of the joint. The Six Synovial Joints Pivot Hinge Saddle Plane Condyloid Ball-and-socket Neck and wrist Fingers and knees Thumb Small bones of wrists and ankles Wrist and lower arm Shoulders and hips Learning Outcome Once you've finished studying this lesson, you could test your ability to name and provide examples of the six types of synovial joints. The hip joint and the glenohumeral shoulder joint are the only ball-and-socket joints of the body. The suture joints of the skull are an example of a synarthrosis, an immobile or essentially immobile joint. The functional classification of body joints is based on the degree of movement found at each joint.