Joints Of The Body PDF

Professor Lindboom-Broberg (LB) Joint Classification Functional Classification Structural Classification Joints Articulations (Joints)  Locations where two or more bones meet Allow mobility while preserving bone strength Amount of movement determined by anatomy  Classifi...

Professor Lindboom-Broberg (LB) Joint Classification Functional Classification Structural Classification Joints Articulations (Joints)  Locations where two or more bones meet Allow mobility while preserving bone strength Amount of movement determined by anatomy  Classification Functional – Amount of motion allowed, or range of motion (ROM) Structural – Anatomical organization Joints Functional classification  Synarthrosis (syn-, together + arthrosis, joint) No movement allowed Extremely strong  Amphiarthrosis (amphi-, on both sides) Little movement allowed Articulating bones connected by collagen fibers or cartilage  Diarthrosis (dia-, through) Freely movable Weakest joints Joints Structural classification  Fibrous  Cartilaginous  Bony  Synovial  All diarthroses are synovial  Professor Lindboom-Broberg (LB) Synovial Joint Anatomy What makes up a moveable joint? Synovial Joints Components of a synovial joint  Articular cartilage Covers bones at joint. Structure resembles hyaline cartilage but with no perichondrium – Matrix contains more water than other cartilages Synovial Joints Components of a synovial joint  Joint (articular) capsule Sac enclosing the articular ends of the bones in a joint Continuous with the periosteum of each bone – Adds strength and mobility to the joint Reinforced with accessory structures (tendons, ligaments) Synovial Joints Components of a synovial joint  Synovial membrane Lines the interior of the joint capsule Secretes synovial fluid into the joint cavity – Fluid lubricates, cushions, prevents abrasion, and supports chondrocytes – Total quantity of synovial fluid usually less than 3 mL Synovial Joints Accessory structures supporting the knee  Provide support and additional stability  Tendons (ex: quadricep tendon) & Ligaments (ex: patellar ligament) Not part of knee joint itself Limits range of motion and provides mechanical support Synovial Joints Accessory structures supporting the knee  Bursa Small, fluid-filled pocket Fills with synovial fluid under excessive friction or pressure Forms in connective tissue outside a joint capsule Reduces friction & shock Synovial Joints Accessory structures supporting the knee  Fat Pads Localized adipose tissue covered by synovial membrane Usually superficial to joint capsule Protect articular cartilage Fill in spaces created as joint moves and joint cavity changes shape Synovial Joints Accessory structures supporting the knee  Meniscus (articular disc) Pad of fibrocartilage between opposing bones in a synovial joint May subdivide a synovial cavity May channel synovial fluid flow Synovial Joints Accessory ligaments  Extrinsic ligaments Separate from the joint capsule Extracapsular ligaments (pass outside the joint capsule) – Example: patellar ligament Intracapsular ligaments (pass inside the joint capsule) – Example: cruciate ligaments (ACL, PCL)  Professor Lindboom-Broberg (LB) Synovial Joint Physiology Synovial Joint Movements Body Movements Synovial Joints Mobility in joints  Greater range of motion = lesser strength Synarthroses are strongest joints and have no movement Diarthroses are the most mobile joints and the weakest  Dislocation (luxation) Movement beyond the normal range of motion Articulating surfaces forced out of position Damages joint structures Pain is from nerves monitoring capsule and surrounding tissue – No pain receptors inside a joint  Professor Lindboom-Broberg (LB) Body Movements How does the BODY move? Body Movements Flexion and extension  Flexion Decreases the angle of the joint  Extension Increases the angle of the joint  Hyperextension Extension past the anatomical position Body Movements Flexion and extension  Lateral flexion Bending the vertebral column to the side Most pronounced in cervical and thoracic regions Body Movements Flexion and extension  Movements of the foot Dorsiflexion – Upward movement of the foot or toes Plantar flexion (planta, sole) – Movement extending the ankle, as in standing on tiptoe Body Movements Abduction and adduction  Movements of the appendicular skeleton  Abduction (ab, from) Movement away from the longitudinal axis in the frontal plane  Adduction (ad, to) Movement toward the longitudinal axis in the frontal plane  Where? Legs, arms Wrists Fingers Body Movements Circumduction  Combination of flexion, extension, abduction, and adduction  Moving a body part such that the distal end traces a circle while the proximal end stays in one position  Where? Leg Arm Body Movements Rotation  When referring to the trunk… Left/Right Rotation Example: Head  When referring to the limbs… Lateral (external) Rotation – Anterior surface of a limb turns away from the long axis of the trunk Medial (internal) Rotation – Anterior surface of a limb turns toward the long axis of the trunk Example: Shoulder, Hip Body Movements Rotation  When referring to the forearm… Movement occurs at the proximal joint between radius and ulna Radial head rotates – Pronation o Turns the wrist and hand from anterior facing to posterior facing – Supination o Palm is turned anteriorly Body Movements Special movements  Opposition Movement of the thumb toward the surface of the palm or pads of other fingers Enables grasping objects  Reposition Movement of the thumb away from the surface of the palms or pads of other fingers Body Movements Special movements  Movements of the foot Inversion (in, into + vertere, to turn) – Twisting motion turning the sole inward Eversion – Opposing motion turning the sole outward Body Movements Special movements  Protraction Moving a part of the body anteriorly in the horizontal plane  Retraction Reverse of protraction; returning the body part to normal position Body Movements Special movements  Depression Moving a body part inferiorly  Elevation Moving a body part superiorly  Examples: Jaw, shoulders  Professor Lindboom-Broberg (LB) Joints of the Body Naming Intervertebral Body Joints  Axial joints – stronger, less movement  Appendicular joints – weaker, more movement The Vertebral Column Intervertebral disc components  Anulus fibrosus Tough outer ring of fibrocartilage Collagen fibers attach to adjacent vertebrae  Nucleus pulposus Soft, elastic, gelatinous core Gives disc resilience Absorbs shock Vertebral Abnormalities Intervertebral disc disease (IVDD)  Bulging disc Weakened posterior longitudinal ligaments Allows compression of disc and distortion of fibrous exterior Tough, outer layer of cartilage bulges laterally Vertebral Abnormalities Intervertebral disc disease (IVDD)  Herniated Disc Disc cartilage breaks through fibrous exterior and protrudes into the vertebral canal Compresses spinal nerves  Professor Lindboom-Broberg (LB) When Joints Go Bad… Arthritis Joint Replacement Joint Disruption Terminology  Rheumatism General pain and inflammation in the bones and/or muscles  Arthritis Rheumatic diseases that affect synovial joints Articular cartilage is damaged Causes can vary (genetic, autoimmune, nutrition, wear & tear) Three types 1. Osteoarthritis 2. Rheumatoid arthritis 3. Gouty arthritis Joint Disruption Osteoarthritis  Most common form of arthritis  Generally age 60 or older 25% of women over 60 (US) 15% of men over 60 (US)  Caused by: Cumulative effects of wear and tear on joints Genetic factors affecting collagen formation Joint Disruption  Normal articular cartilage  Articular cartilage with Smooth, slick surface osteoarthritis Thick cartilage with Rough, bristly collagen fibers homogeneous matrix Increases friction – Promotes further degeneration Joint Disruption Treatment  Regular exercise & physical therapy Promote synovial fluid movement (nutrients in, waste out) Promote ligament and tissue strengthening/repair  Anti-inflammatory drugs Restrict excessive friction and limit damage Artificial Joints  May be method of last resort for arthritis treatment if other methods fail to slow disease progression  Can restore mobility and relieve pain  High-impact activities are restricted after replacement  New joints (hips/knees) can last more than 15 years Joint Disruption