11.2: Movement

Key vocabulary

prior learning and retrieval practice

Essential idea: The roles of the musculoskeletal system are movement, support and protection.

NoS: Developments in scientific research follow improvements in apparatus—fluorescent calcium ions have been used to study the cyclic interactions in muscle contraction. (1.8)

S1: Annotation of a diagram of the human elbow.

Guidance from the syllabus: Elbow diagram should include cartilage, synovial fluid, joint capsule, named bones and named antagonistic muscles.

U1: Bones and exoskeletons provide anchorage for muscles and act as levers.

U2: Synovial joints allow certain movements but not others.

U3: Movement of the body requires muscles to work in antagonistic pairs.

A1: Antagonistic pairs of muscles in an insect leg. Create a quizlet diagram showing the pairs of muscles in insect legs

U4: Skeletal muscle fibres are multinucleate and contain specialized endoplasmic reticulum.

U5: Muscle fibres contain many myofibrils.

U6: Each myofibril is made up of contractile sarcomeres.

U7: The contraction of the skeletal muscle is achieved by the sliding of actin and myosin filaments.

U8: ATP hydrolysis and cross bridge formation are necessary for the filaments to slide.

U9: Calcium ions and the proteins tropomyosin and troponin control muscle contractions.

Using information from the exercise above and from your textbook. Compose an answer to this following IB question:

• Explain the process of muscle contraction (8 marks)

S2: Drawing labelled diagrams of the structure of a sarcomere.

• • Guidance from the syllabus: Drawing labelled diagrams of the structure of a sarcomere should include Z lines, actin filaments, myosin filaments with heads, and the resultant light and dark bands.

S3: Analysis of electron micrographs to find the state of contraction of muscle fibres.