1. Muscles of the Muscular System Mr. MacMillan Grade 12 Exercise Science

4. Sliding Filament Theory 1.Message released from CNS 2.Travels to PNS to designated location 3.Moves down axon to axon terminal 4.Ach released to sarcolemma 5.Calcium released at sarcoplasmic reticulum 6.Myosin attaches to binding sites on Actin 7.ATP broken down causing the sliding of actin along myosin 8.Contraction occurs as long as Calcium is present

5. Types of Muscle Contraction Concentric – Shortening of muscle fibres Eccentric – Lengthening of muscle fibres Isometric – Muscle does not change in length – Wall sits, planks, moving an immovable object

6. Muscle Contraction During Exercise Isotonic Exercise – Involves a controlled shortening and lengthening of the muscle – As the weight is lifted throughout the range of motion, the muscle shortens. – A classic example is weight training with dumbbells and barbells, push-ups, sit-ups

7. Muscle Contraction During Exercise Isometric Exercise – Muscle fibres maintain constant length throughout the entire contraction and there is no motion – This training is effective in developing particular muscle groups and is useful in rehabilitation exercises

8. Muscle Contraction During Exercise Isokinetic Exercise – Involves using machines to control the speed of contractions within the range of a muscle’s motion. – Seeks to combine the best features of both isometric and isotonic training

9. Advantages and Disadvantages AdvantagesDisadvantages Isotonic TrainingRelatively CheapUneven force throughout each exercise Ability to exercise all major muscle groups Exercises may not fully strengthen each muscle group Isometric trainingVery cheap and convenientWill increase strength at one joint angle at a time Specific muscles can be isolated Can be only part of a strength training program

10. Read page 42 in textbook “ Muscle Fibre” – Responses to training Continue to read Excitation-Contraction Coupling, Transverse Tubulae and The Role of Calcium

11. Facial Muscles

13. Muscles are also available on page 44 of textbook Fill in the worksheet with appropriate names