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Chapter 9: Joints - Coggle Diagram

- - - - Tibial Collateral Ligament
        
        Found on medial side of the joint capsule
        
        Runs fro the medial epicondyle of the femur to the medial condyle of the tibia
      - Fibular Collateral Ligament
        
        Found on the lateral side of the joint capsule
        
        Descends from the lateral epicondyle of the femur to the head of the fibula
    - - Cruciate Ligament
        
        2 strong intracapsular ligaments that stabilize the knee joint
        
        Cross each other like an X
        
        Each runs from the tibia to the femur
        
        Named for its site of attachment to the tibia
        
        Act as restraining straps to prevent undesirable movements at the knee joint
        
        Function together to lock the knee when you stand
        
        Anterior Cruciate Ligament
        
        Attaches to the anterior part of the tibia in the intercondylar area
        
        Passes posteriorly to attach to the femur on the medial side of the lateral condyle
        
        Prevents anterior sliding of the tibia
        
        Posterior Cruciate Ligament
        
        Arises from the posterior intercondylar area of the tibia
        
        Passes anteriorly to attach to the femur on the lateral side of the medial condyle
        
        Stronger than the anterior cruciate
        
        Prevents forward sliding of the femur or backward displacement of the tibia
- - - - Chronic Arthritis
        
        Rheumatoid Arthritis
        
        A chronic inflammatory disorder
        
        Idiopathic
        
        Symptoms: joint pain & swelling, anemia, osteoporosis, muscle weakness & cardiovascular problems
        
        Treatment: NSAIDs, immune suppressants, joint replacement (prosthesis)
        
        Gouty Arthritis (Gout)
        
        Uric acid buildup causes pain in joints
        
        Treatment: drugs, water, avoidance of alcohol/urines
        
        Osteoarthritis
        
        Most common type of "wear & tear" arthritis
        
        Treatment: moderate activity, mild pain relievers, capsaicin creams
- - - - Synarthroses
        Immovable joints
        
        Restricted to axial skeleton
      - Amphiarthroses
        Slightly movable joints
        
        Restricted to axial skeleton
      - Diarthroses
        Freely movable joints
        
        Predominate in the limbs
    - - Fibrous
        
        Adjoining bones united by collagen fibers
        
        Connected by dense regular connective tissue
        
        No joint cavity
        
        Most are immovable or only slightly movable
        
        3 Types of Fibrous Joints
        
        Sutures
        
        Found only in skull
        
        Joint is held together with very short, interconnecting fibers & bone edges interlock
        
        The fibrous tissue is continuous with the periosteum around the flat bones
        
        The edges of the joining bones are wavy & interlocking
        
        Sutures As We Age
        
        Allow for the brain to expand during childhood
        
        During middle age, the fibrous tissue ossifies & the skull bones fuse
        
        At this stage, the closed sutures are called syntheses
        
        Syndesmoses
        
        Joint is held together by a ligament
        
        The bands of fibrous tissue can vary in length, but is longer than in sutures
        
        Movement
        
        Amount of movement allowed at a syndesmosis depends on the length of the connecting fibers
        
        If fibers are short, little to no movement is allowed
        
        Ex: distal tibiofibular articulation
        
        If fibers are long, a large amount of movement is possible
        
        Ex: interosseous membrane between radius & ulna
        
        Gomphoses
        
        Peg-in-socket fibrous joint
        
        Only example is the articulation of a tooth with its socket
        
        Periodontal ligament holds tooth in socket
      - Cartilaginous
        
        Adjoining bones united by cartilage
        
        No joint cavity
        
        Not highly movable
        
        Synchondroses
        Junction of cartilage
        
        Bones united by hyaline cartilage
        
        Ex: epiphyseal plate & the immovable joint between 1st rib's costal cartilage & the manubrium
        
        Functionally classified as synarthroses
        
        Immovable joints
        
        Symphyses
        
        Bones united by fibrocartilage
        
        Fibrocartilage is the main element
        
        Hyaline cartilage is also present as articular cartilages on the bony surfaces
        
        Ex: intervertebral discs & the pubic symphysis of pelvis
        
        Functionally classified as amphiarthroses
        
        Slightly movable joints
        
        Provides strength with flexibility
        
        Fibrocartilage
        
        Resists tension & compression
        
        Can act as a resilient shock absorber
        
        Hyaline Cartilage
        
        Reduces friction between the bones during movement
      - Synovial
        
        Adjoining bones separated by joint cavity, covered with articular cartilage & enclosed with an articular capsule lined with synovial membrane
        
        Most movable joint in the body
        
        All synovial joints are diarthroses
        
        Freely movable joints
        
        Contains a fluid-filled joint cavity
        
        Features of Synovial Joints
        
        Articular Cartilage
        
        Ends of opposing bones are covered by articular cartilages composed of hyaline cartilage
        
        Absorb compressive forces placed on the joint
        
        Keep the bone ends from being crushed
        
        Joint (Articular) Cavity
        
        Unique to synovial joints
        
        Joint cavity is a potential space that holds a small amount of synovial fluid
        
        Joint/Articular Capsule
        
        Joint cavity is enclosed by a 2-layered joint/articular capsule
        
        Fibrous Layer
        
        Outer layer of dense irregular connective tissue
        
        Continuous with the periosteum layer of the joining bones
        
        Strengthens the joint so that the bones aren't pulled apart
        
        Synovial Membrane
        
        Inner layer composed of loose connective tissue
        
        Lines the joint capsule & all the internal joint surfaces not covered by cartilage
        
        Function is to make synovial fluid
        
        Synovial Fluid
        
        Viscous liquid inside the joint cavity
        
        Also occurs within the articular cartilages
        
        Filtrate of blood, arising from capillaries in the synovial membrane
        
        Contains special glycoprotein molecules
        
        Secreted by fibroblasts in synovial membrane
        
        Makes synovial fluid a slippery lubricant that eases the movement at the joint
        
        Weeping Lubrication
        
        Pressure placed on joints during normal movement squeezes synovial fluid into & out of articular cartilages
        
        Nourishes the cells in the articular cartilages & lubricates the free surfaces of these cartilages
        
        Allows the adjoining bones to move across each other with minimum friction
        
        Reinforcing Ligaments
        
        Some synovial joints are reinforced & strengthened by bandlike ligaments
        
        Usually, the ligaments are capsular
        
        Sometimes the ligaments are extra capsular or intracapsular
        
        Capsular Ligaments
        
        Thickened parts of the fibrous layer of the articular capsule
        
        Extracapsular Ligaments
        
        Located just outside the capsule
        
        Ex: fibular & tibial collateral ligaments of knee
        
        Intracapsular Ligaments
        
        Internal to the capsule
        
        Covered with a synovial membrane that separates them from the joint cavity
        
        Ex: anterior & posterior cruciate ligaments in knee
        
        Nerves and Vessels
        
        Nerves
        
        Sensory nerve fibers innervate the articular capsule
        
        Some fibers detect pain
        
        Most fibers monitor how much the capsule is being stretched
        
        This is one way the nervous system senses our posture & body movements
        
        Vessels
        
        Most of the blood vessels supply the synovial membrane
        
        Extensive capillary beds produce the blood filtrate of synovial fluid
        
        Articular Disc/Meniscus
        
        Certain synovial joints contain a disc of fibrocartilage (articular disc or meniscus)
        
        Ex: temporomandibular (jaw) joint, stereoclavicular joint, knee joint
        
        The disc extends internally from the capsule & completely/partly divides the joint cavity in two
        
        Occur in joints whose articulating bone ends have somewhat different shapes
        
        Minimizes wear & damage
        
        May allow 2 different movements at the same joint
        
        Bursae & Tendon Sheaths
        
        Contain synovial fluid & often are associated with synovial joints
        
        "Closed bags of lubricant"
        
        Reduce friction between body elements that move over one another
        
        Bursae
        
        Flattened fibrous sac lined by a synovial membrane
        
        Occurs where ligaments, muscles, skin, tendons or bones overlie each other & rub together
        
        Tendon Sheath
        
        An elongated bursa that wraps around a tendon
        
        Like a bun around a hot dog
        
        Occur only on tendons that are subjected to friction
        
        Ex: tendons that travel through joint cavities or are crowded together within narrow canals
        
        Movements at Synovial Joints
        
        Gliding
        
        Gliding of 1 bone surface across another
        
        The nearly flat surfaces of 2 bones slip across each other
        
        Occurs at:
        
        The joints between the carpals & tarsals
        
        Between the flat articular processes of the vertebrae
        
        Angular Movements
        
        Change the angle between 2 bones
        
        Increase/decrease the angle between 2 bones
        
        Flexion & Extension
        
        Moments that occur primarily in the sagittal plane
        
        Flexion
        
        Decreases the angle between the bones
        
        Brings 2 bones closer together
        
        Examples:
        
        Flexion of neck/trunk (chin down)
        
        Fingers (making a fist)
        
        Flexion of forearm toward the arm at the elbow
        
        Flexion at the shoulder when moved in an anterior direction
        
        Flexion at the hip when the thigh moves anteriorly
        
        Extension
        
        Reverse of flexion
        
        Occurs at the same joints as flexion joints
        
        Increases the angle between the joining bones
        
        Is a straightening action
        
        Hyperextension
        
        Bending a joint back beyond its normal range of motion
        
        Abduction & Adduction
        
        Move a body part along the frontal plane
        
        Abduction
        
        Movement of limb away from the body midline
        
        Examples:
        
        Raising the arm/thigh laterally
        
        Spreading the fingers apart
        
        Bending the trunk away from the body midline to the right or left tis called lateral flexion rather than abduction
        
        Adduction
        
        Opposite of abduction
        
        Movement of a limb toward the body midline
        
        Circumduction
        
        Moving a limb/finger so that it describes a cone in space
        
        Complex movement
        
        Combines flexion, abduction, extension & adduction
        
        Rotation
        
        Rotation about a bone's long/longitudinal axis
        
        Occurs along the transverse plane
        
        Only movement allowed between the 1st 2 cervical vertebrae
        
        Entire vertebral column also rotates, twisting the whole trunk to the right/left
        
        Occurs at hip & shoulder joints
        
        Rotation of limbs may be toward median plane or away from it
        
        Medial Rotation
        
        Anterior surface turns toward the median plane of body
        
        Lateral Rotation
        
        Opposite movement of medial rotation
        
        Special Movements
        
        Don't fit into the other categories & only occurs at a few joints
        
        Elevation & Depression
        
        Ex: mandible when chewing
        
        Elevation
        Lifting a body part superiorly
        
        Depression
        Moving the elevated part inferiorly
        
        Protraction & Retraction
        
        Nonangular movements in the anterior & posterior directions, respectively
        
        Ex: mandible when you jut your jaw out (protraction) & when you bring it back (retraction)
        
        Supination & Pronation
        
        Refers to movements of the radius around the ulna
        
        Supination
        
        When the forearm (specifically radius) rotates laterally so that the palm faces anteriorly
        
        This is standard anatomical position
        
        Pronation
        
        Occurs when the radius rotates medially so that the palm faces posteriorly
        
        Brings the radius across the ulna so that the 2 bones form an X
        
        Opposition
        
        Saddle joint between metacarpal I & the trapezium
        
        Allows for opposition of the thumb
        
        Action of moving thumb across the palm to touch the tips of the same hand's other fingers
        
        This is what makes human hands a good tool for grasping & manipulating objects
        
        Inversion & Eversion
        
        Special movements of the foot at the inter tarsal joints
        
        Inversion
        
        Turn the sole medially
        
        Eversion
        
        Turn the sole laterally
        
        Dorsiflexion & Plantar Flexion
        
        Up & down movements of the foot at the ankle
        
        Dorsiflexion
        
        Lifting the foot so that its superior surfaces approaches the tin
        
        Plantar Flexion
        
        Depressing the foot/elevating the heel
        
        Standing on tippy-toes
        
        Types of Synovial Joints
        
        Functional Classification of Synovial Joints
        
        Uniaxial
        
        Movement occurs around a single axis
        
        Hinge Joint
        
        Flexion & extension
        
        Ex: Elbow joints, interphalangeal joints
        
        Pivot Joint
        
        Rotation
        
        Ex: proximal radioulnar joint, atlantoaxial joint
        
        Biaxial
        
        Movement can occur around 2 axes
        
        The joint enables motion along both the frontal & sagittal planes
        
        Condylar Joint
        
        Flexion & extension
        
        Adduction & abduction
        
        Ex: metacarpophalangeal (knuckle) joints, wrist joints
        
        Saddle Joint
        
        Flexion & extension
        
        Adduction & abduction
        
        Ex: carpometacarpal joints of the thumbs
        
        Multiaxial
        
        Movement can occur around all 3 axes & along all 3 body planes: frontal, sagittal & transverse
        
        Ball-and-Socket
        
        Flexion & extension
        
        Adduction & abduction
        
        Rotation
        Ex: shoulder joints & hip joints
        
        Nonaxial
        
        Adjoining bones don't move around a specific axis
        
        Plane Joint
        
        Nonaxial movement
        
        Gliding
        
        Ex: inter carpal joints, intertarsal joints, joints between vertebral articular surfaces
        
        Factors Influencing the Stability of Synovial Joints
        
        Articular Surfaces
        
        Articular surfaces of the bones in a joint fit together in a complementary manner
        
        Rarely play a role in joint stability, but some do
        
        Ex: ball & deep socket of the hip joint, elbow joint & ankle joint
        
        Ligaments
        
        Capsules & ligaments of synovial joints help hold the bones together & prevent excessive or undesirable motions
        
        The more ligaments a joint has, the stronger it is
        
        When other stabilizing factors are inadequate the tension is placed on the ligaments, which fail
        
        Once stretched, ligaments stay stretched
        
        Can only stay stretch ~6% beyond its normal length before snapping
        
        Medial/Inferior Ligaments
        
        Resist excessive abduction
        
        Lateral & Superior Ligaments
        
        Resist excessive adduction
        
        Anterior Ligaments
        
        Resist excessive extension & lateral rotation
        
        Posterior Ligaments
        
        Resist excessive flexion & medial rotation
        
        Muscle Tone
        
        Constant, low level of contractile force generated by a muscle even when it's not causing movement
        
        Helps stabilize joints by keeping tension on the muscle tendons that cross over joints external to the joint capsule