Muscle/StructureofMuscle/ClassificationofMuscle/TheSarcomere

The sarcomere

There is a common nomenclature used to describe the components of the sarcomere.

1. A band. This is the region of the sarcomere that contains the thick filaments. It forms the dark band that helps to give the muscle fiber the striated look. Note that there may be thin filaments in the A band region.

2. I band. This is the region over adjacent sarcomeres that does not contain thick filaments. It consists of the Z disc and the length of the thin filaments that do not overlap the thick filaments.

3. H zone. This is the region of the sarcomere that is solely the thick filament.

4. Z disc. This forms the border of the sarcomere and consists of proteins that anchor the thin filaments in place.

5. M line. This is found in the center of the sarcomere and consists of proteins that anchor the thick filaments in place.

Challenge Quiz

You must wait for the CORRECT! 正確!

<GIFT> //LEVEL:2 //RAND The A band consists of {thin filaments only~thick filaments only~=both thick and thin filaments}.

//LEVEL:2 //RAND The I band consists of {=thin filaments only~thick filaments only~both thick and thin filaments}.

//LEVEL:2 //RAND The H zone consists of {thin filaments only~=thick filaments only~both thick and thin filaments}.

//LEVEL:2 //RAND The Z disc is found {~=on the border~in the middle} of the sarcomere

//LEVEL:2 //RAND The M line is found {~on the border~=in the middle} of the sarcomere