Muscles and Movements

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.e The Sliding Filament Theory)

• Muscle fibers can be, fully relaxed, slightly- moderately or fully contracted

Analyze electron micrographs to find the state of contraction of muscle fibers