How muscles contract by Eskinder Demeke


The sliding filament theory- before discussing this theory we should know :

 Sarcomere- a stripped patterns or striations that are arranged in stacked pattern through out the muscle tissue.

 They contain actin/thin and myosin/thick filaments.

The interaction between the actin and myosin proteins is the basis of muscular contraction.

The sliding filament theory states that during contraction A-band (group of thick filaments) remain relatively constant in length

According to this theory the sliding of actin past myosin generates muscle tension. Since actin is contained on the lateral ends of each sarcomere ( z- band)

any shortening of the z- band results in muscle contraction.

 

Retrieved from- http://www.nicholls.edu/biol-ds/Biol156/Lectures/muscles%202.pdf 

                       -http://www.ncbi.nlm.nih.gov/books/NBK9961/