Answer:
Sarcomere
Explanation:
The sarcomere is the smallest contractile unit of muscle. It extends from one Z disc to the next and therefore, is the region between two consecutive Z discs. It contains an A band flanked by half an I band at each end. Contraction of a muscle fiber occurs as the sarcomeres within the myofibrils shorten. During the shortening of the sarcomere, the thin actin filaments slide past the thick myosin filaments and approach one another. The resultant shortening of the I band and complete disappearance of H zone cause contraction of muscle fiber.
They run up a tree and steal them from all the birds nests then swallow them
All arteries leaving the heart, arteries carrying blood to the body, (I'm not sure about pulmonary arteries, but since it is an artery I am assuming it has oxygenated blood", and the aorta
Answer:
have different strength .......
