The muscular system

• Tendons


  Attaches muscle to bone
• Latissimus dorsi


  Muscle that pulls down
• Deltoid


  • Responsible for shoulder movement
• Rotator cuff


  • Muscles that sit on the scapula
• Pectorals


  • Chest muscles, used for inspiration (breathing in)
• The only thing muscles can do is pull
• Triceps


  Responsible for elbow extension
• Abdominals


  Responsible for breathing expiration
• Hip Flexors


  Flex the hip
• Gluteals


  When they contract, they move the leg behind
• Hamstrings


  When they contract, they flex the knee
• Quadriceps


  When they contract and flex up, they straighten the knee
• Gastrocnemius


  When it pulls up, it points the toes: plantar flexion
• Tibialis anterior


  On the front of the tibia, responsible for dorsiflexion
• Sternocleidomastoid


  Breathing muscle, pulls up when breathing in
• Achilles tendon


  Connects muscle to bone, when it contracts it pulls on the tendon and the toes pull down
• Flexion


  Angle of the joint decreasing
• Extension


  Angle of the joint increasing
• Abduction


  Moving away from the midline of the body
• Adduction


  Moving towards the midline of the body
• Rotation


  Turning around a fixed point
• Circumduction


  Circular movement around a joint
• Antagonistic muscle pairs


  • Deltoids
  • Pectorals
  • Biceps
  • Abdominals
  • Hip Flexors
  • Quadriceps
  • Tibialis anterior
  • Trapezius
  • Rotator cuff
  • Triceps
  • Latissimus dorsi
  • Gluteals
  • Hamstrings
  • Gastrocnemius
• Muscle contraction


  1. Muscle shortens and pulls on the tendon

  2. Tendon pulls on the bone

  3. Results in movement
• Antagonistic muscle pairs


  Muscles that work together to move joints
• Agonist


  The muscle that causes the main movement
• Antagonist


  The muscle that relaxes to allow the movement
• Antagonistic muscle pairs


  Work together to move joints, such as the biceps and triceps, quadriceps and hamstrings, hip flexors and gluteals
• Antagonistic muscle action at the knee

  1. Quadriceps and hamstrings work together

  2. Agonist is the hamstring

  3. Antagonist is the quadriceps
• Antagonistic muscle action at the elbow

  1. Biceps and triceps work together

  2. Agonist is the biceps

  3. Antagonist is the triceps
• Isotonic contraction


  Muscle contraction that results in movement, e.g. push-up
• Isometric contraction


  Muscle contracts but no movement occurs, e.g. plank
• Concentric contraction


  Muscle shortens/contracts
• Eccentric contraction


  Muscle lengthens but still contracts
• Isometric contraction example: Standing still on top of the diving board in position for a dive
• Isotonic contraction example: Doing a push-up
• Isotonic contraction example: Throwing a ball in for a throw-in in football
• Bones of the skeletal system


  • Skull
  • Vertebrae
  • Clavicle
  • Ribs
  • Sternum
  • Scapula
  • Humerus
  • Radius
  • Ulna
  • Carpals
  • Metacarpals
  • Phalanges
  • Femur
  • Patella
  • Tibia
  • Fibula
  • Tarsals
  • Metatarsals
  • Phalanges
• Functions of the skeletal system

  • Mineral storage
  • Protection of vital organs
  • Production of red blood cells
  • Allows movement
  • Provides shape and support
• Antagonistic muscle pairs


  • Biceps and triceps
  • Gastrocnemius and tibialis anterior
  • Hip flexors and gluteals
  • Quadriceps and hamstrings