When Sarcomeres Go Wrong

Last post we talked about how the healthy sarcomere functions. This time we'll discuss one thing that can go wrong.

When circulation of blood through a muscle is especially poor, the amount of oxygen and nutrients available to individual sarcomeres can nosedive. Without adequate oxygen and sugar, the sarcomere stops responding to the electrical impulses telling it to contract. It needs oxygen and energy to do so and these are unavailable.

The contraction of a sarcomere uses energy, not its relaxation, so the sarcomere is shortened when it freezes up. Many sarcomeres affected in this way cause the entire muscle to get shorter and stiffer.

But it gets worse. Because the sarcomere pumps its own blood, when it stops pumping it can no longer bring in fresh blood. The depleted blood remains. So the sarcomere can't recover. It needs an intervention.