During a muscle contraction, what gets shorter?

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

a. Muscle fibers generate more tension if the starting length of their sarcomeres is very short.

During a muscle contraction, the ___________ pulls on the ___________, shortening the muscle.

Myosin storage myopathy is a rare congenital condition where some of the myosin folds incorrectly in certain skeletal muscles creating clumps. Individuals with this condition exhibit muscle weakness and may be delayed in learning to walk as infants. What changes would you expect to see if you were to examine the sarcomere of an individual with this condition?

The contractile proteins of the sarcomere include which of the following?

Which protein contributes to the structural integrity of the sarcomere?

The box in the image below surrounds what structure?