BIO10004 WK3

• Parallel muscles


  • Fascicles are parallel to the long axis of muscle
• Skeletal muscle fiber


  Can contract until shortened to 30 percent
• Convergent muscles


  • Muscle fascicle extend over broad area come together, converge on common attachment site
• Pennate muscles


  • Fascicles form common angle with tendon
• Bone as levers


  To increase muscle efficiency
• Lever


  Can change (1) the direction of an applied force, (2) the distance and speed of movement produced by an applied force, and (3) the effective strength of an applied force
• Origin


  The point of attachment that does not change position when muscle contracts
• Insertion


  The point of attachment of a muscle; the point that is easily moveable
• Muscle can have multiple origins and single insertion if several tendons are at one end
• Agonist


  A muscle responsible for a specific movement (Prime mover)
• Antagonist


  A muscle whose action opposes that of a particular agonist
• Synergist


  A muscle that assist a prime mover in performing its primary action
• Fixator


  A synergist that assists agonist by preventing movement at another joint
• Externus or superficialis


  Muscles visible at body surface
• Extrinsic


  Superficialis that position or stabilize organs
• Intrinsic


  Muscles located within an organ
• Structural characteristics


  • Origin and insertion
  • Shape and size
  • Longus, teres (long and round), brevis (short), magnus, major, maximus, minor, minimus
• Actions


  • Flexor
  • Extensor
  • Pronator
  • Abductor
  • Adductor
  • Rotator
• Appendicular muscles


  Muscles of shoulders, upper limbs, pelvis and lower limbs. Position and stabilize pectoral and pelvic girdles. Move upper and lower limbs.