Here, weâre concerned, like Lord Chesterfield, with âthe average cat.â On average, female cats live one to two years longer than male cats. On average, indoor cats live longer than outdoor cats. On average, wild, homeless, and feral cats live dramatically shorter lives than domestic cats.
During contraction, myosin heads bind to actin molecules of the. thin filaments. Flexing of the myosin heads pulls the thin filaments over the thick. filaments - shortening the sarcomere. Muscle contraction requires.
Muscles can only contract and pull. Therefore, joints have to have two or more muscles working opposite each other. As the first muscle contracts, so the second muscle relaxes. As the second muscle contracts, so the first muscle relaxes.