Articulation (Joints) Prof. Abdulameer Al-Nuaimi a.alnuaimi@sheffield.ac.uk abdulameerh@yahoo.com

Joints Joint is a unions between two or more bones Bones actually do not contact one another directly, some connective tissue is always present between the surfaces of the articulated bones There are four type of joints depending on the way in which bones are connected with each another 1-Bony joint, as in the hip bone where its three parts are joined by bony union after age of puberty. 2-fibrous joints, where bones are connected by dense irregular connective tissue. Such as skull suture, Syndesmosis (articulation of the roots of the teeth with sockets Gomphosis and also the inferior tibiofibular joint) and Interosseous membrane (between tibia and fibula)

3-cartilaginous joints, which have some types of cartilages as a connecting tissue between the bones. There are primary and secondary cartilaginous joints. A- Primary cartilaginous joint: the bony surfaces are united by hyaline cartilage as seen in the union of the body and the growing ends in a developing long Bones. (immobile joint) B- Secondary cartilaginous joint (Symphysis): the bony surfaces are covered with hyaline cartilage and united by a fibrocartilaginous disc (slightly mobile joint) Bony, fibrous and cartilagenous joint are immobile or have a little movements 

4-Synovial Joints: the articulated bones are covered with hyaline cartilage. A fibrous capsule is attached near to the articular margins of the bones. The surfaces of the interior of the joint except those covered by cartilage are lined by a delicate vascular synovial membrane which secretes synovial fluid into the joint, as in knee joint These joints are freely movable joint

Joints Functional classification of joints depends on the degree of movement they permit. Joints are classified as follows 1- Synarthrosis:- An immovable joints. A type of joints  in which there is no joint cavity, and permit very little or no movement under normal conditions.

2- Amphiarthrosis:- A slightly movable joints. 3- Diarthrosis:- A freely movable joints; these come in a variety of shapes and permit several different type of movements.

Bony joints

1-Sutures found between the bones of the skull Fibrous Joint 1-Sutures found between the bones of the skull 

Fibrous Joint 2- Syndesmosis 3-Interosseous membrane: articulating bones are united by a real sheet of dense irregular connective tissue (Interosseous membrane between tibia and fibula) a- between long bones of the body, example distal Tibiofibular joint  b-Gomphosis between the root of a tooth and the sockets in the maxilla or mandible

Cartilaginous Joint Primary Cartilaginous joint Secondary

Synovial Joint Component

Types of Synovial Joint (Freely mobile joints) 5

Synovial Joint

Synovial Joint

Synovial Joint

Stability of joints Stability of a joint is achieved through 1- Bony factor: Ball and socket is the most stable joint 2- Ligamentous factor ligaments of the joint) 3- Muscular factor, this is the most important factor in joint stability muscles around the joint

Kuala Lumpur February 2015 Sun Set Thank You Thank You