In the earlier posts we have already learned about the types of joints like movable joints and immovable joints. Now in this post we would learn some what about immovable joints.
The joining of two or more bones is the articulation or the joint. Some of the immovable joints between the skull bones are the suture joints A suture is a type of articulation in which the bones that makeup and the bones are close together. In this suture joint, the union of bones is connected by connective tissue.
Other joints, such as those between the vertebrae, are partially movable joints. Most of the joints however allow considerable movement. Those which are freely movable joints are called as synovial joints. This synovial joint is also called as diarthrosis which is the most movable type of joint in the body of a mammal. Like with other joints mostly, synovial joints gains movement at the meeting of the articulating bones. Examples of the synovial joints are the ball-and-socket type of joint(hip joint; the head of the femur fits into the acetabular fossa of the ilium) and the hinge type(elbow, knee and ankle joints).
Description of the synovial joint:
The vascularized connective tissue which has a lack of basement membrane all are consisted in Synovial tissue and also sterile. The bones in this joint (synovial joint) are separated by a joint capsule. This joint capsule composed of fibrous cartilage tissue and the articular cartilage. Ligaments also called fibrous bands, or sheets, of connective tissue often anchor the bones together around the joint capsule to become strength. The surface of the bones at the joint is covered with a smooth cartilage surface called the articular cartilage.
The synovial cavity membrane lies under the joint capsule and lines the synovial cavity between bones. The synovial cavity is filled with a particular and special lubricating fluid produced by the synovial membrane. This synovial fluid consists of water and nutrients that nourish as well as lubricate the joints, so that friction on the articular cartilage is minimal.
Bursae singular bursa are the closed sacs of synovial fluid lined with a synovial membrane and are located near a joint. These are formed in the spaces between tendons which are called connective tissue binding muscles to bones, ligaments which are called connective tissue binding bones to bones and bones. Bursae lubricate these areas where friction would normally develop close to the joint capsule.
In the next post we discuss some of the Vocabulary terms.
To go to the prior lesson please click the link below
To go to the first lesson, please visit the link below