1. 11.2: Movement

2. Bones & exoskeletons Bones and exoskeletons provide anchorage for muscles and act as levers. Exoskeletons = external Levers = change size and direction of force. Levers use E – effort force, F – fulcrum pivot and R – resultant force

3. Bones are organs because they contain different tissues. Functions include: 1.Support the body 2.Blood cells form in bone marrow 3.Levers 4.Protection 5.Storage of minerals (Ca, P)

4. 1 st, 2 nd & 3 rd class levers Diagram pg. 477, shows the effort force, fulcrum and resultant force at three locations within the body. In order to achieve these movements, muscles will work as pairs of antagonistic muscles. See fig. 3, page 477.

6. The elbow joint

7. Joint partFunction CartilageReduces friction, absorbs compression Synovial fluidLubricates, provides nutrients to cartilage cells Joint capsuleSurrounds joint, unites connecting bones TendonsAttach muscles to bone LigamentsConnect bone to bone Biceps muscleContracts so arm can bend (flexion) Triceps muscleContracts so arm can straighten (extension) HumerusLever, anchoring muscles RadiusLever, biceps muscle UlnaLever, triceps muscle

9. Types of muscle Skeletal/striated Cardiac Smooth/non-striated

10. Striated muscle cells have multiple nuclei, within the sarcolemma region. Cytoplasm of muscle cells is called the sarcoplasm – many glycosomes and lots of myoglobin Sarcoplasmic reticulum membranous sacs, surround myofibrils Myofibrils, rod like. Run length of the cell. Able to contract. (see above) Myofibrils are made of contractile sacromeres

11. The sacromere

12. ActinMyosin Thin filaments (8nm diameter) Thick filaments (16nm diameter) Contains myosin-binding sites Myosin heads with actin- binding sites Form helical structuresCommon shaft like structure Regulatory proteins: tropomyosin & troponin Heads also known as cross-bridges, ATP binding sites & ATPase enzyme

13. Relaxed or contracted?

14. Overview http://highered.mcgraw- hill.com/sites/0072495855/student_view0/chapter 10/animation__sarcomere_contraction.html Detail https://highered.mcgraw- hill.com/sites/0072495855/student_view0/chapter 10/animation__myofilament_contraction.html Context http://highered.mheducation.com/sites/007249585 5/student_view0/chapter10/animation__action_pot entials_and_muscle_contraction.html

15. The role of ATP

16. The steps When action potential reaches neuromuscular junction acetylcholine is released Acetylcholine binds to sarcolemma Sodium enters post synapse (sarcolemma ion channels open) Muscle action potential (Acetylcholinase breaksdown acetylcholine) Muscle action potential moves through T tubules, causing calcium ions to be released. Calcium ions flood into sarcoplasm, and bind with troponin on the actin myofilaments – exposing myosin-binding sites 1.Myosin heads contain ATPase (splits ATP releasing energy) 2.Myosin heads, bind to myosin binding sites on actin (tropomysin – protein) 3.Myosin-actin cross bridge rotate towards centre of sarcomere 4.ATP binds to myosin head, detaching myosin from actin 5.Calcium ion levels fall (if no new action potential). Troponin-tropomyosin complex returns to normal position, blocking myosin binding sites. 6.Muscle is now relaxed

17. You must be able to compare electron micrographs of muscles in three states – relaxed, fully contracted & partially contracted. Pg. 482, fig. 18

18. Joint vocabulary Flexion Extension Abduction Adduction Circumduction Rotation Decrease in angle between connecting bones Increase in angle between connecting bones Bone moves away from body midline Bone moves towards body midline Distal (far end) of limb moves in a circle Bone revolves around longitudinal axis