2 Learning Objectives To know the different joint types To understand how to classify joint typesTo be able to discuss the importance of the structure and function of a synovial joint
3 JointsThe human skeleton is jointed to allow movement.Muscular contraction causes the bones to move about the joints.A joint is where two or more bones meet and muscles act together to cause movement.
4 Types of Joints There are 3 main types of joint found in the body. Fibrous/ immovable jointsThe bones at an immoveable joint cannot move - they overlap or interlock, and are held together by a tough fibre, e.g. the skull.2. Cartilaginous/slightly moveable jointsThe bones at a slightly moveable joint can only movea little - they are held together by strong strapscalled ligaments and are joined by protective padsknown as cartilage, e.g. the ribs.3. Synovial joint/freely moveableAt a freely moveable joint the bones move freely.They are also known as synovial joints, andare the largest group of joints found in the body,e.g. the hips, shoulders and knees.
5 Freely Moveable Joints Freely Moveable joints are also known as Synovial Joints.They are freely moving and occur where 2 or more bones meet.There are about 70 freely moveable joints in the human skeleton.These interest us the most because they allow the greatest range of movement and are found in the appendicualr skeleton
6 Cartilage Hyaline or Articular cartilage- found on the surface of bone 2. Yellow Elastic cartilage- elastic and found in theexternal ear3. White Fibrocartilage- tough, dense tissue thatacts as a shock absorber. Found between the vertebrae
8 Articular/hyaline Cartilage – A material which covers the end of each bone, and which helps prevent friction between the joint.Absorbs compression placed on the joint,protects the joint.2. Joint Capsule – The outer layer is a tough fibrous layer called the fibrous capsule.Increases stabilityThe inner layer is called the synovial membraneSecretes synovial fluid, strengthens the joint
10 3. Synovial Membrane– Thin membrane which lines the inside of the joint capsule. It produces synovial fluid4. Synovial Fluid – The fluid which surrounds the joint and is contained in the joint cavity.Reduce friction between the cartilageNourish the cartilageGet rid of any waste debris
11 4. Ligaments – A band of strong fibrous tissue, helps prevent dislocation. Connect bone to bone5. Tendons– Strong connective tissue that attached muscle to bone.Connect muscle to muscle6. Bursa- pad of fat provide cushioning between the fibrous capsule and a bone or muscle.Cushion the joint and act as shock absorbers
12 The Synovial Joint of the Knee The knee is a hinge joint.FemurArticular(hyaline)CartilageJoint capsuleCruciate LigamentsSynovial MembranePatellaSynovial FluidJoint cavityTibia/FibulaTendons
13 The Synovial Joint of the Hip The Hip is a ball and socket joint.CartilagePelvisSynovial FluidSynovial MembraneLigamentsTendonsFemur
14 Label the diagram of a synovial joint using a colour code system TASKLabel the diagram of a synovial joint using a colour code systemYOU MAY BE ASKED TO LABEL A SYNOVIAL JOINT INEXAM OR EXPLAIN THE STRUCTURE AND FUCTION
15 2. List two features that increase joint stability and give their specific function?
17 Types of Synovial Joints Synovial joints are classifed according to the shape of thearticulating surface.KEYBall & Socket JointHinge JointPivot JointGliding JointSaddle JointCondyloid Joint
18 Write down another example KEY TERMARTICULATION-The different bones that form to make the jointEXAMPLEJoint Joint type Articulating bones MovementElbow Hinge joint Humerus, radius, ulnaWrite down another example
19 1. Ball and Socket JointsThe ball has a head shaped of one bone which articulateswith a cuplike socket.Allows the greatest range of movementExamplesHIPSHOULDER
20 2. Hinge Joints They are cylindrical shaped of 1 bone articulates with a depression of an adjacent boneMovement is restricted to bending and straighteningEXAMPLESELBOWKNEE
21 3. Pivot JointsThese are rounded, pointed or concave of one bone which articulates which a ring shaped bone.Movement is restricted to 1 bone rotating around the longitudinal axis.EXAMPLE VERTEBRAE OF THE NECK
22 4. Gliding Joints The articulating surfaces are flat. It allows limited movementEXAMPLESHAND BETWEEN THE CARPELS
23 5. Saddle Joints The articulating surfaces are shaped like a saddle It allows very limited movementEXAMPLETHUMB JOINT
24 6. Condyloid JointsThe surfaces are flatter and oval forming a shallow jointIt allows the second greatest range of movement.EXAMPLEWRIST JOINT
25 Structure and function Hyaline/Articular cartilageStructure: Smooth, spongy cartilage that covers end of bone.Function: prevent friction between bonesabsorb compression placed on the jointprotect bone from getting crushedJoint capsule:Structure: Outer layer is a tough fibrous layer- fibrous membrane.
26 The inner layer- synovial membrane Function:strengthen the jointsecrete synovial fluidSynovial FluidStructure; slippery fluid, contained in the joint cavityFunction; reduce friction between cartilagenourish the articular cartilageget rid of waste debris in jointLigamentStructure; band of strong fibrous tissueFunction; connect bone to bone
27 Meniscus (cartilage)Structure: white fibrocartilageFunction: improves the fit between bone endsincreases joint stabilityreduces wear and tear at jointBursaStructure:fluid filled sacsFunction: prevent friction where bones, ligaments and muscles may rub together
28 PLENARY Identify the bones that articulate at the shoulder joint? (2 marks)Identify the bones that articulate at the elbow joint? (3 marks)
29 Ball and Socket Joints Hinge Joints Examples HIPSHOULDERThe ball has a head shaped of one bone which articulateswith a cuplike socket.Allows the greatest range of movementHinge JointsEXAMPLESELBOWKNEEThey are cylindrical shaped of 1 bone articulates witha depression of an adjacent boneMovement is restricted to bending and straightening
30 Pivot Joints Gliding Joints VERTEBRAE OF THE NECK These are rounded, pointed or concave of one bone which articulates which a ring shaped bone.Movement is restricted to 1 bone rotating around the longitudinal axis.HAND BETWEEN THE CARPELSGliding JointsThe articulating surfaces are flat.It allows limited movement
31 Saddle Joints Condyloid Joints EXAMPLE THUMB JOINT The articulating surfaces are shaped like a saddleIt allows very limited movementCondyloid JointsThe surfaces are flatter and oval forming a shallow jointIt allows the second greatest range of movement.EXAMPLEWRIST JOINT