What is the zone that disappears when actin filaments slide?

1 Answer
Jun 3, 2017

Answer:

At the centre of contractile unit, sarcomere, there is H zone. It is also at the centre of dark band/A band. The H zone disappears when actin filaments slide inside A band during contraction of myofibril.

Explanation:

bio1903.nicerweb.com

(https://d2gne97vdumgn3.cloudfront.net/api/file/P8C7n1eSSSkeR0YFdQ5w)

figures.boundless-cdn.com

(https://d2gne97vdumgn3.cloudfront.net/api/file/KPOvTQ59Qfef6eMURHeg)

The illustration above is that of sarcomere. It is delimited by Z lines on both sides. There is dark A band where myofilaments myosin and actin overlap, but at its centre in relaxed condition a light area could be seen known as H band. When actin filaments slide inside A band during contraction, H zone is naturally obliterated.