山东大学：《医学机能学实验》课程教学课件（PPT讲稿）07 A SINGLE MUSCLE TWITCH AND TETANIC CONTRACTION

ASINGLE MUSCLE TWITCH ANDTETANIC CONTRACTION

A SINGLE MUSCLE TWITCH AND TETANIC CONTRACTION

A SINGLE MUSCLE TWITCH When a muscle is stimulated, it contractsafter a latent period and this is immediatelyfollowed by relaxation, this is called singlemuscle twitchStart stimulating21.latent period2.contraction period3.relaxation period

A SINGLE MUSCLE TWITCH • When a muscle is stimulated, it contracts after a latent period and this is immediately followed by relaxation, this is called single muscle twitch. 1.latent period 2.contraction period 3.relaxation period 1 2 3 Start stimulating

TETANIC CONTRACTION When a muscle is stimulated at very highfrequency(100/s), the successivecontractions completely fuse together andcannot be distinguished one from the otherThis state of sustained contraction is calledTetanization

TETANIC CONTRACTION • When a muscle is stimulated at very high frequency(100/s), the successive contractions completely fuse together and cannot be distinguished one from the other. This state of sustained contraction is called Tetanization

L④?2?

Prepare a nerve and musclepreparationSciatic nerve-gastrocnemius of frog

Prepare a nerve and muscle preparation Sciatic nerve-gastrocnemius of frog

femurbicepsfemoris股骨Iricepsfemoris股二头肌股三头肌半膜肌股二头肌semimembranous半膜肌musclebiceps femorisSemimembranousmuscle

biceps femoris Semimembranous muscle Quadriceps femoris semimembranous muscle biceps femoris femur

procedure1.fix the knee joint with the help ofpins2.tie the tendon and cut it below thethread3. cut all the structures below theknee joint except gastrocnemiusmuscle

procedure 1.fix the knee joint with the help of pins 2.tie the tendon and cut it below the thread 3. cut all the structures below the knee joint except gastrocnemius muscle

股骨股二头肌半膜肌股二头肌半膜肌CAB

: 4.connect the tendon to tension transducerwith hook of clip. 5. Place the nerve over electrodes

• 4.connect the tendon to tension transducer with hook of clip • 5. Place the nerve over electrodes

Tension transducer换能器Sciatic nerve-gastrocnemius muscle preparation坐骨神经肠肌标本BL-310肌动器or Powerlab刺激输出Stimulus output

Tension transducer Sciatic nerve-gastrocnemius muscle preparation Stimulus output or Powerlab