Topic 4: Movement Analysis

• isotonic contraction


  change in muscle length

  
• concentric

  muscle shortens

  
• eccentric


  muscle lengthens

  
• isometric contraction


  body doesn't move but muscle contracts

  
• isokinetic contraction


  muscle contracts so attached body part moves at a constant speed around the joint

  
• agonist


  moving muscle; contracts concentrically to move bone

  
• antagonist


  opposes the motion; muscle relaxes while the other contracts or contracts eccentrically to control balance

  
• fixator


  stabilizes the origin of a prime mover; contract isometrically to stop other parts moving
• synergist

  neutralizes; contract isometrically yo prevent unwanted movement
• reciprocal inhibition


  when agonist contracts and antagonist relaxes

  
• Delayed Onset Muscle Soreness (DOMS)


  caused by eccentric muscle contractions, forcefully breaks cross-bridges between actin and myosin

  
• Dendrite


  collect signals

  
• Cell Body

  contains nucleus

  
• Nucleus


  Control center of the cell

  
• Axon


  the neuron extension that passes action potential through its branches to muscle fibres

  
• Motor end plate


  the flattened end of a motor neuron that transmits action potential to a muscle

  
• Synapse


  where the axon terminal meets the muscle cell membrane

  
• Axon terminal


  the end of an axon where it connects to the sarcolemma

  
• Role of neurotransmitters in muscle contraction

  Acetylcholine released from vesicles, diffuse across synaptic cleft, attaches to cell receptor to open Sodium Ion passageway, Na+ floods the muscle creating new action potential, this moves across the sarcolemma and down T-tubes causing muscle contraction.

  
• Transverse tubes (T-tubes)


  infoldings of cell membrane

  
• Sarcoplasm reticulum


  stores calcium

  
• Sarcolemma


  muscle cell membrane

  
• nucleus of skeletal muscle

  multiple nuclei

  
• sarcoplasm


  cytoplasm of a muscle cell

  
• mitochondria


  releases cellular energy

  
• myofibril


  tightly packed filament bundles found within skeletal muscle fibers

  
• Actin


  thin myofilament

  
• Myosin

  thick myofilament

  
• Z-line


  A dark thin protein band to which actin filaments are attached in a muscle fiber, end of sarcomere

  
• sarcomere


  contains the two filaments

  
• A-band


  dark area; extends length of the thick filaments

  
• I-band

  lighter band

  
• H-zone


  only myosin

  
• Flexion


  Decreases the angle of a joint - bends a joint

  
• Extension


  increases the angle of a joint - straightens a joint

  
• Abduction


  Movement away from the midline of the body

  
• Adduction


  Movement toward the midline of the body

  
• Circumduction


  circular movement at the far end of a limb

  
• Rotation


  twisting movement(medial and lateral)

  
• Pronation


  turning the palm downward