Essential Idea:
The roles of the musculoskeletal system
are movement, support and protection
Understandings:
- Bones and exoskeletons provide anchorage for muscles and act as levers
- Synovial joints allow certain movements but not others
- Movement of the body requires muscles to work in antagonistic pairs
- Skeletal muscle fibres are multinucleate and contain specialised endoplasmic reticulum
- Muscle fibres contain many myofibrils
- Each myofibril is made up of contractile sarcomeres
- The contraction of the skeletal muscle is achieved by the sliding of actin and myosin filaments
- ATP hydrolysis and cross bridge formation are necessary for the filaments to slide
- Calcium ions and the proteins tropomyosin and troponin control muscle contractions
Applications:
- Antagonistic pairs of muscles in an insect leg
Skills:
- Annotation of a diagram of the human elbow
- Drawing labelled diagrams of the structure of a sarcomere
- Analysis of electron micrographs to find the state of contraction of muscle fibres