muscular system

• muscles types

  • voluntary (skeletal)
  • involuntary (smooth)
  • cardiac (heart)
• voluntary (skeletal)

  • under your control
  • attached to skeletons via tendons
  • contract/pull to create movement
• involuntary (smooth)

  • not under your control
  • work automatically (controlled by nerve system)
  • found in organs of digestive system
  • circularaty and urinary system
• cardiac (heart)

  • 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 ligaments - anterior cruciate ligament (ACL) posterior cruciate ligament (PCL)
• tendons -achilles tendon found in 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 maximus

  • location: bum
  • function: extension at hip
• hip flexors

  • location: front of hip
  • function: flexion at hip
• quadriceps

  • location: front of thigh
  • function: extension at knee
• hamstring

  • location: back of thigh
  • function: flexion at knee
• gastrocnemius

  • 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 bone to create movement
• muscles 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 bicep are antagonistic pairs
• antagonistic pair: gluteus maximus hip flexor
• antagonistic pair: hamstring and quadriceps
• antagonistic pairs: gastrocnemius tibialis anterior
• there are three muscle types

  • type IIa
  • type IIx
  • type I
• type I muscle fibres are slow twitch so they have high fatigue resistance and work for hours because they have slow contraction time and a high blood supply
• marathon runner use type I muscle fibres
• type IIa muscle fibres are moderate twitch because they have medium fatigue resistance and a moderate contraction time and blood supply
• type IIa muscle fibres are used by 400m runners
• type IIx are fast twitch muscle fibres because they have very fast contraction time so they have a low fatigue resistance and less than a minute use because they have low blood supply
• type IIx are used by 100m sprinters