muscular system

• Muscle Types


  • Voluntary (Skeletal)
  • Involuntary (Smooth)
  • Cardiac (heart)
• Voluntary (Skeletal)


  Under your control, attached to skeleton by tendons, contract/pull to create movement
• Involuntary (Smooth)


  Not under your control, work automatically (controlled by nervous system), found in organs of digestive, circulatory and urinary systems
• Cardiac (heart)


  We cannot control it (MYOGENIC), regulates heart rate
• ligaments are elastic fibres that join bone to bone to support the skeleton and allow movement at joints
• tendons are non-elastic fibres that attach muscle to bone to allow a pulley like action of muscles
• ligaments- cruciate ligament in the knee
• tendons- achilles tendon found in the heel/ankle
• Deltoid


  • Location: Shoulder • function: abduction at shoulder
• Pectoralius Major


  • Location: Chest
  • Function: Adduction at Shoulder
• Latissimus dorsi


  • Location: Back
  • Function: Adduction out at shoulder
• Biceps


  • Location: Front upper arm
  • Function: Flexion at elbow
• Triceps


  • Location: Back upper arm
  • Function: Extension at elbow
• External obliques


  • Location: Side of stomach
  • Function: Flexion/rotation of spine
• Gluteaus


  • Location: Buttox
  • Function: Extension at hip
• Hip-flexors


  • Location: Front of hip
  • Function: Flexion at hip
• Quadriceps


  • Location: Front of thigh
  • Function: Extension at knee
• Hamstrings


  • Location: Back of thigh
  • Function: Flexion at knee
• Gastroceremus


  • Location: Calf back of lower leg
  • Function: Plantar-flexion at ankle
• Tibialis anterior


  • Location: Front of shin
  • Function: Dorsi-flexion at ankle
• muscles pull on bones to create movement
• musckes are arranged in antagonistic pairs
• agonist is the prime mover that contracts and pulls
• antagonist relaxes and allows the joint to work
• the tricep and biceps are antagonistic pairs
• antagonistic pair: gluteus maximus and hip flexors
• antagonistic pair: hamstrings and quadriceps
• antagonistic pair: gastrocnemius and tibialis anterior
• there are three muscle fibre Types: type I type IIa and type 11x
• type I muscle fibres are slow twitch so they have a high fatigue resistance and work for hours because they have a slow contraction time and a high blood supply and so are red in colour
• marathon runners use type I muscle fibres
• Type IIa muscle fibres are fast twitch because they have a quite high fatigue resistance and so a quite high contraction time and blood supply giving them a light red colour
• Type IIa muscle fibres can be used for up to 80 minutes so are used by 1500m runners
• type 11x are fast twitch fibres because they have a very fast contraction time so they have a low fatigue resistance and last less than a minute because they have a low blood supple and have a white appearance
• type 11x muscle fibres are used by 100m sprinters