Joints & Muscle Tissue

• What is a joint

  A connection between two bones in the skeleton
• Three types of joints

  Synovial

  Fibrous

  Cartilagenous
• Synovial Joint

  Surrounded by Articulate Capsule

  Outer fibrous Layer

  Inner Synovial Layer - lubricates
• Types of Synovial Joints

  Ball & Socket

  Plane

  Pivot

  Hinge

  Saddle

  Condylar
• Fibrous Joints

  Exhibit little to no mobility
• Three types of Fibrous Joints

  Sutures

  Gomphosis

  Syndesmosis
• Sutures

  Fibres joint found only in skull
• Gomphosis


  Located in mouth; anchors tooth to socket
• Syndesmosis

  a fibrous joint that is linked together by strong ligaments or membranes e.g Ulna & Radial
• Cartilaginous Joint

  A joint that is made entirely from hyaline or fibrocartilage
• Two types of Cartilaginous joints

  Synchronous

  Symphyses
• Synchrondrosis Joint

  Bones connected by Hyaline Cartilage e.g first sternocostal joint that unites first rib with sternum
• Symphysis Joints

  Bones connected by fibro cartilage, found along midline e.g pubic symphysis
• Mjoint Movement Classification

  Diarthrosis

  Amphiarthrosis

  Synarthrosis
• Diarthrosis

  Freely moveable joint - all synovial joints are this e.g knee, mandible
• Amphiarthrosis

  Slightly Mobile Joint e.g distal joint between tibia and fibula
• Synarthroses Joint

  Immovable Joint e.g the coronal suture. can be considered Syndesmosis joint
• ROM

  Refers to Diathrosis & Synovial Joints
• Axes Of Movement

  Uniaxial

  Biaxial

  Polyaxial
• Uniaxial Movement

  Back & Forth between singular axes

  • Pivot & Hinge Joints
• Biaxial Movement

  Moves between two distinct axes

  • Condyle & Saddle
• Polyaxial Movement

  Move through all three axes

  • Ball & Socket
• Ball & Socket Joint

  involves;

  Flexion - extension

  Adduction - abduction

  Internal - external rotation

  e.g Glenohhumeral & Acertabulofemoral joint
• Hinge Joint

  One axes; Frontal

  Extension - Flexion

  e.g Knee
• Pivot Joint


  Uniaxial - allows rotation in the head

  Vertical axes
• Condylar Joint

  Biaxial - radiocarpal joint

  Frontal & Sagittal Plane
• Saddle Joint

  where opposing surfaces are reciprocally convex & concave

  Carpometacarpal joint of thumb
• Anatomy of skeletal Muscle

  Thousands of myofibrils come together to make muscle fibre, they contain mitochondria, nuclei & membrane
• Structure of skeletal muscle

  Muscle fibres string together to make fascicle muscles which make up organs like bicep brachii
• Myofibril

  Divided into two segments called sarcomere.
• Sarcomere

  Contains;

  Myosin

  Actin
• Myosin

  Thick filaments strands
• Actin

  Thin Filament Strands
• Sliding Filament Theory

  Myosin Head binds to actin, corms cross-bridge;

  Myosin heads pull actin - shortening the sarcomere

  ATP assists myosin detachment from actin
• Calcium Pump & Troponin

  calcium ions released - binds with troponin causing tropomyosin to change shape and allowing binding myosin head
• Sarcoplasm

  The cytoplasm of cell; calcium storage
• Sarcomere

  The basic unit of muscle contraction - found in muscle fibres - contains myosin & actin filaments

  Assists with sliding filament theory
• Contraction Coupling

  the motor unit conducts action potential, travels to muscle fibres - Excitation Couping theory
• Excitation Couping theory

  ATP travels across sarcolemma, conducted into fibre by T-Tubules & contacts with SR
• Triad

  T-Tubule + Two Adjacent Terminal Cisternae of SR