TYPES OF MUSCLE • There are 3 types of muscle: - Involuntary (smooth) • Cardiac • Voluntary (skeletal/ striated/striped).
TYPES OF MUSCLE - INVOLUNTARY • Involuntary (smooth) muscle is found in the internal organs of the body e.g. the stomach and intestines. • It is not under our ‘conscious’ control but works automatically e.g. the stomach contracts automatically to digest food.
TYPES OF MUSCLE - CARDIAC • Cardiac muscle is only found in the heart. • It is also involuntary and never stops working until we die e.g. the heart is always working to pump blood around the body.
TYPES OF MUSCLE – VOLUNTARY/SKELETAL • Voluntary muscle is associated with movement, and can be found all over the body attached to the skeleton. • It is under ‘conscious’ control e.g. we use it when we choose to move. • This is the type of muscle that you will learn about in this unit.
MAJOR MUSCLE GROUPS • Biceps (bends arm at elbow) • Triceps (straightens arm at elbow) • Deltoid (abducts arm) • Trapezius (shrugs shoulders) • Quadriceps (straightens leg at knee) • Hamstring (bends leg at knee) • Gastrocnemius (raises body onto toes) • GluteusMaximus (straightens leg at hip) • Pectorals (brings arms together in front of body) • Abdominals (bends upper body at waist) • Latissimus Dorsi (pulls elbows towards back)
HOW MUSCLES WORK • Muscles work in pairs. When one muscle contracts (the AGONIST or PRIME MOVER), the other muscle relaxes (the ANTAGONIST). This creates movement of a bone at a joint. • The INSERTION of a muscle is where it attaches and resists pull. • The ORIGIN of a muscle is where it attaches and exerts pull.
HOW MUSCLES WORK • A Bicep Curl in the Arm • The bicep would be the prime mover/agonist. • The tricep would be the antagonist. • The origin of the bicep would be at the shoulder. • The insertion of the bicep would be at the elbow.
EXAMPLES OF ANTAGONISTIC MUSCLES • Biceps and triceps in the upper arm Quadriceps and hamstring in the upper leg
TENDONS • Tendons attach muscle to bone • TENDON OF INSERTION – exerts pull • In a bicep curl the tendon at the bottom of the bicep that attaches to the elbow • TENDON OF ORIGIN – resists pull • In a bicep curl the tendon at the top of the bicep that attaches to the shoulder
MUSCLE FIBRE TYPES • Fast twitch fibres • Fast powerful contractions • Enough energy for 10seconds of exercise • Anaerobic energy systems used • E.g. weightlifting, sprinting, swimming 50m
MUSCLE FIBRE TYPE • Slow twitch fibres • slower and less powerful contractions • utilise oxygen to provide energy for longer • aerobic energy systems used • e.g. cross country skiing, Tour de France (cycling), marathon.
MUSCLE FIBRE TYPE • Everybody has both types of fibre type • It is possible to increase the efficiency that the muscle fibres work at with training • Different activities use both fibre types for different amounts of time • e.g. marathon runners use slow twitch fibres for most of the race but fast twitch fibres for the sprint finish
MUSCLE FIBRE TYPE AND SPORT Most of game Short sprints Sprinting for the ball in a rally Most of match Duration of match Punching
EFFECTS OF TRAINING • HYPERTROPHY – increase in muscle size, strength and flexibility • ATROPHY – decrease in muscle size, strength and flexibility (wasting of the muscle)
EFFECTS OF TRAINING • MARATHON RUNNER • slow twitch muscle fibres adapt to utilise energy more efficiently and for longer periods of time • delays the onset of muscle fatigue • as little muscle bulk as possible • SPRINTER • more muscle fast twitch fibres are generated (muscle bulk) to give more power output • muscles are able to maximise stored energy to give greater bursts of all-out activity