Muscular system

• A voluntary muscle is attached to the skeleton and are under your control they help move the body.
• A type of voluntary muscle are your usual muscles e.g. biceps
• An involuntary muscle work your internal organs without effort from you e.g muscles in blood vessels control the amount of blood flowing to voluntary muscles. Also your digestive system.
• Cardiac muscle is a type of involuntary muscle that forms the heart. They are only found in the heart and can be made fitter by doing cardiovascular training.
• Cardiac muscle:

  In sport it speeds up to meet the demand of working muscles so they have a supply of oxygen and also send blood to the lungs.
• Involuntary muscles:

  In sport this allows regulation of blood pressure so it goes where it's needed.
• Voluntary muscles:

  In sport you tell them what to do so you can move and compete. There are 12 voluntary muscles you need to know.
• Ligament stabilized joints and attach bone to bone.
• Biceps- flexion at the elbow at the shoulder joint. E.g when curling weights.
• Triceps - extension of the elbow at the shoulder joint. E.g. during a jump shot in netball.
• Pectoralis major- adduction and flexion at the shoulder. E.g. during a forehand drive in tennis.
• Hip flexors- flexion of the upper leg at the hip. E.g lifting the knee when sprinting.
• Gluteus maximus- extension of the upper leg at the hip. E.g. kicking back in swimming.
• Deltoid- flexion , extension , abduction or circumduction at the shoulder. E.g butterfly stroke in swimming.
• Latissimus dorsi- extension , adduction or rotation at the shoulder. E.g circumducting your arm to bowl a ball in cricket.
• External obliques- rotation of flexion at the waist. Abduction of the torso at the hips. E.g leaning to the side to dodge a punch in boxing.
• Tibialis anterior- dorsiflexion at the ankle. E.g during a heel  side turn and snowboarding. In the last phase of a high kick in karate with your heel pointing up.
• Gastrocnemius- plantar flexion at the ankle. E.g standing on the toes in ballet point work. Preparing to do a cartwheel on the beam in gymnastics.
• Quadriceps- extension at the knee. Extension of lower leg in the final phase of kicking a football into the net.
• Hamstrings- flexion at the knee. When doing a hop in triple jump.
• Muscles do one thing- pull. To make a joint move in two directions you need two muscles that can pull in  opposite directions.
• Antagonistic muscles are pairs of  muscles that work against each other.

  One muscle contracts while the other one relaxes and vice versa.

  The relaxing muscle is called the antagonist.

  The working muscle is the agonist.
• In antagonistic muscle pairs  Each muscle is attached to two bones by tendons. Only one of the Bones connected at the joint actually moves.
• Knee- hamstrings and quadriceps.

  In flexion the agonist is the hamstrings and the antagonist is the quadriceps.

  In extension the agonist is the quadriceps and the antagonist is the hamstrings.
• Elbow- biceps and triceps.

  In flexion the agonist is the biceps and the antagonist is the triceps.

  In extension the agonist  is the triceps and the antagonist is the biceps.
• Hip- hip flexors and gluteus maximus.

  In  flexion the agonist is the hip flexors and the antagonist is the gluteus maximus.

  In extension the agonist is the gluteus maximus and the antagonist is the hip flexors.
• Ankle- gastrocnemius and tibialis anterior.

  In plantar flexion the agonist is the gastrocnemius and the antagonist is the tibialis anterior.

  In dorsiflexion the agonist is the tibialis anterior and the antagonist is the gastrocnemius.
• All muscles are made up of fibres.

  These muscle fibres can be slow twitch or fast twitch.
• Slow twitch

  Type I- suited to low intensity aerobic work (e.g marathon running) as they can be used for a long period of time without fatiguing.
• Fast twitch

  Type IIA- used in anaerobic work but can be improved through endurance training to increase their resistance to fatigue.

  Type IIX- used in anaerobic work can generate a much greater force than other fiber types but fatigue quickly. Useful and short busts of exercise. E.g 100m sprint.
• Which muscle fiber type is most suited for used in a long distance triathlon?

  Type I
• main function of the quadriceps?

  extension at the knee
• sporting example using quadriceps?

  jumping to score in basketball
• describe a joint action caused by lattisimus dorsi?

  adduction at the shoulder

  for example when swinging a golf club