Muscles and Movements

Ligaments – attach bone to bone State the roles of bones, ligaments, muscles, tendons and nerves in human movement Bones – carry the body’s weight and serve as anchors for muscles to work against and cause movement Ligaments – attach bone to bone Muscles -have elastic properties which allow movement to occur by becoming shorter and thicker; pulling the bones with them

Cont’d Tendons – attach muscle to bone Nerves – stimulates muscle to contract and create movement

State the roles of bones, ligaments, muscles, tendons and nerves in human movement Bones – provide attachment sites for skeletal muscle Ligaments – connect bone to bone; restrict movement at joints Muscles – provide force needed for skeletal motion Tendons – attach muscle to bone Nerves – stimulate and coordinated muscles contraction

Skeletal Joints Junctions between bones Cartilage – reduces friction where bones meet Synovial fluid – lubrication; reduces friction Joint capsule – seals the joint and holds in the synovial fluid

Elbow Joint

Outline the functions of the human elbow joint Articular cartilage – reduces wear and tear, reduces friction Synovial fluid – lubricates and shock absorbs Joint capsule – seals the joint space and provides stability Humerus, radius and ulna – upper arm (origin) and lower arm (insertion) Antagonistic muscles – bicep (flexor of R&U), tricep (extensor of R&U)

Compare movements of the hip joint and knee joint Hip joint - is a ball and socket joint that can move in multiple directions. (flexion, extension, abduction, abduction, medial and lateral rotation) Knee joint – flexion and extensionj

Structure of striated muscle fibers •Muscle fibers/fibres – multinucleate muscle cells consist of myofibrils, sarcomeres, actin – myosin

Structure of a sarcomere & Sarcomere contraction Draw and label a diagram to show the structure of a sarcomere, including Z lines, actin & myosin filaments (w/heads) and light and dark bands

Striated Muscle Micrograph

Sarcomere TEM

Explain how skeletal muscle contracts (i Explain how skeletal muscle contracts (i.e The Sliding Filament Theory)

Analyze electron micrographs to find the state of contraction of muscle fibers Muscle fibers can be, fully relaxed, slightly- moderately or fully contracted