Week 4 Joints PDF

Introduction JOINTS Classification (Structurally and functionally) Movements around Synovial joints Types of Synovial joints Selected Synovial joints Homeostatic Imbalances of Joints Developmental Aspects Introduction - Joints or articulation are sites where two or more...

Introduction JOINTS Classification (Structurally and functionally) Movements around Synovial joints Types of Synovial joints Selected Synovial joints Homeostatic Imbalances of Joints Developmental Aspects Introduction - Joints or articulation are sites where two or more bones meet. - They serve holding bones of the skeleton together and give the skeleton mobility - They are the weakest parts of the skeleton, even their structure enables them to resist crushing, tearing, and various forces that threaten to force them out of alignment. By: Dr. Ata Ali 2 Joint Classification - Classified Structurally or Functionally - Structural classification focuses on the material which bind bones together and the presence of a cavity. - Functional classification is based on the amount of movement allowed at that joint and known as: 3 By: Dr. Ata Ali  Structural joints  There are three types: fibrous, cartilaginous and synovial joints A. Fibrous Joints - Bones are joined by fibrous tissues - No joint cavity is present - Movement is very little i.e. no movement - Three types: suture, syndesmoses and interosseous membrane a. Suture : found only in skull, and fibrous tissues in adult become ossified and joints are then called synostoses (bony junction). b. Syndesmoses : bones are connected by a cord or sheath of fibrous tissues called ligament. Examples are radius and ulna, tibia –fibula. > Another example is called Gomphoses : bones are connected in a fibrous socket found only in teeth. c. Interosseous membrane: dense irregular CT between Radius-ulna and Tibia- fibula By: Dr. Ata Ali 4 Fibrous joints By: Dr. Ata Ali 5  B. Cartilaginous Joints - Bones are joined by hyaline or fibrocartilage. - No joint cavity is present - Very little movement - Two types: Synchondroses and Symphyses a. Synchondroses: Hyaline cartilage is present between articulating bones. * Example: first ribs with Manubrium. b. Symphyses: Joint is fibrocartilage cover the articular surfaces. *Examples: intervertebral discs and pubic bones in pelvis. By: Dr. Ata Ali 6 Cartilaginous Joints By: Dr. Ata Ali 7  C. Synovial joints I. Characterization - Articulating bones are separated by a fluid-containing cavity - Substantial freedom of movement ( freely movable joints) - Found in all joints of limbs. - Have 5 distinguishing features: 1. Articular cartilage: hyaline cartilage covers the opposing bone surfaces 2. Joint cavity: filled with synovial fluid 3. Articular capsule: fibrous double- layered capsule 4. Synovial membrane: loose connective tissue lines fibrous capsule 5. Synovial fluid: fill free space of the cavity. Derived from blood infiltration in synovial membrane. - Contains hyaluronic By: Dr. Ataacid Ali for renewing the fluid. 8 Synovial joint By: Dr. Ata Ali 9  Other characterizations of some synovial joints Some synovial joints are reinforced by 1- ligaments, 2- fatty pad between capsule and membrane, 3- fibrocartilage disc separating bones 4- Bursae and tendon sheath: - not part of synovial joint, but found closely associated with them. - Bursae are bags of fluids to reduce friction - Tendons sheath is elongated bursa wrap a tendon completely 10 By: Dr. Ata Ali Bursae and tendon sheath By: Dr. Ata Ali 11 II. Stability of synovial joints -depends on three factors: a. Articular surface give minimal stability depending on cavity depth. deep socket give more stability as in hip joint. b. Ligament: more ligaments give more stability c. Muscle tone (low contractile activity of muscle at rest): the tendon of the muscle give the most stability force of the joint By: Dr. Ata Ali 12 III. Movement of Synovial joints : - depend on muscle attached with the bone joints. - Movement ranges between * nonaxial (slipping , gliding movement), * uniaxial (one direction), * biaxial ( two planes, angular) or * multiaxial (all planes, rotational). By: Dr. Ata Ali 13 1. Gliding movement: - The simplest movement in one plane occurs in metacarpals and metatarsals bones. By: Dr. Ata Ali 14 2. Angular movement (changes the angles between two bones): - Flexion-extension: Decrease (flexion) or increase (extension) the angle between bones. # Examples: bending the head, elbow, By: Dr. Ata Ali 15 - Abduction-adduction: move the organ away or toward the medial section. # Examples: fingers and toes. - Circumduction: move a limb around By: Dr. Ata Ali 16 3. Rotational movement: it is turning the bone around its own axis. # Examples: humerus and femur bones. By: Dr. Ata Ali 17 4. Special movements - Supination-Pronation: back and forward movement. i.e. Radius around ulna. - Inversion-Eversion: movement of the foot medially or laterally. - Protraction- Retraction: anterior and posterior in transverse plane i.e. mandible - Elevation-Depression: superior and inferior movement of the jaw. - Opposition: touching the thumb with other finger in the same hand. By: Dr. Ata Ali 18 Special movement 19 By: Dr. Ata Ali By: Dr. Ata Ali 20 IV. Types of Synovial joints:( six types) a. Plane joint: flat articular surface, i.e gliding bones in carpals. b. Hinge joint: concave-convex surface between the two bones, i.e. elbow. c. Pivot joint: conical head protrude in a sleeve ligament of the other bone ,i.e. atlas and axis vertebrae. d. Condyloid joints: oval surface of one bone with concavity surface of the other bone, i.e. phalanges, knee. e. Saddle joint: both bones have concave and convex surfaces to allow free movement, i.e. carpal and metacarpal bones. f. Ball-Socket joint: multiaxial joint where spherical head of a bone is inserted in a socket of another bone. i.e. shoulder and hip By: Dr. Ata Ali 21 Synovial types By: Dr. Ata Ali 22 V. Selected Synovial Joint: - Have the distinguishing features of synovial joint (cavity, cartilage, capsule, membrane and fluid). -These joints are shoulder, hip, elbow and knee. By: Dr. Ata Ali 23 1. Shoulder joint: - Slightly deepen in glenoid cavity. - Ligaments: *Coracohumeral, *Glenohumeral, *Transverse humeral. - Tendons of biceps muscles and rotary cuff tendon (4 tendons) By: Dr. Ata Ali 24 Shoulder joint By: Dr. Ata Ali 25 2. Elbow joint: - Thin capsule allow free movement of the elbow. - Strong ligaments: * ulnar-radial collateral ligaments, - Tendons of several muscles (biceps, triceps, brachial and others). By: Dr. Ata Ali 26 Elbow joint By: Dr. Ata Ali 27 3. Hip joint: - Deep Acetabulum socket - Fastened by * Fibrocartilage rim called acetabular labrum * Thick capsule * Several strong ligaments * Muscle tendons of the thigh By: Dr. Ata Ali 28 Hip joint By: Dr. Ata Ali 29 4. Knee Joints: - The most complex joint in the body, - Three joints in one: * Intermediate between patella and femur, *Lateral and *Medial between tibia-fibula and femur). - Cavity is partially enclosed by capsule By: Dr. Ata Ali 30 - Ligaments in knee joints: * Three ligaments from patella to tibia * Extracapsular ligaments include: a. Fibular and tibular collateral ligaments b. Oblique popliteal ligament. c. Arcuate popliteal ligament * Intracapsular ligaments: cruciate ligaments By: Dr. Ata Ali 31  Knee Joints Anterior View Posterior View By: Dr. Ata Ali 32 Homeostatic Imbalances of Joints - Joint pain and malfunction can be caused by: * Injuries * Inflammatory * Degenerative By: Dr. Ata Ali 33  A. Joint injuries: - Most injuries include: 1. Sprains: due to ligament stretching or tearing, i.e Knee and ankle are common sprains 2. Cartilage injuries: involve knee tearing cartilage in aerobic persons. 3. Dislocations: bones are forced out of their position. By: Dr. Ata Ali 34  Knee injurie s By: Dr. Ata Ali 35  B. Inflammatory and Degenerative conditions: - Inflammatory that affect joints include: 1. Bursitis: it is an inflammation caused by excessive stress or bacterial infection. 2. Tendonitis: inflammation of tendon sheath. 3. Arthritis: it is inflammatory or degenerative disease. By: Dr. Ata Ali 36 3. Arthritis: it is inflammatory or degenerative disease. - Acute arthritis results from bacterial infection - Chronic arthritis include * Osteoarthritis, * Rheumatoid arthritis and *Gouty arthritis By: Dr. Ata Ali 37 By: Dr. Ata Ali 38 - Chronic arthritis a. Osteoarthritis: - it is non inflammatory disease - result by normal aging process. - It appears due to imbalance production of enzyme that breaks down articular cartilage for unknown reason. - As the disease progresses, the affected joint may make a crunching noise when moving. By: Dr. Ata Ali 39 b. Rheumatoid arthritis: - it is autoimmune disease arises after bacterial infection (streptococcus). - Antibodies elicited against antigens of bacteria attack self antigen of joint membrane. c. Gouty arthritis: due to uric acid accumulation in joint cavity. d. Lyme disease: due to bacterial infection (Spirocheates) of knee By: Dr. Ata Ali 40  Lyme Disease Symptoms Rheumatoi d arthritis 41 By: Dr. Ata Ali Developmental Aspects of Joints - Joints are formed from mesenchymal cells parallel with bone development (By Week8) - Usually, joint function well until middle age. - And after that, disorders of joints begin to appear. By: Dr. Ata Ali 42