Sarcomere
The sarcomere is the smallest contractile unit of muscle.
sarcomere
sarcomere
Sarcomere
The smallest contractile unit of a muscle fiber is the sarcomere.It is composed of contractile myofilaments known as actin and myosin.
sarcomere
A muscle fiber is made of many contractile units called sarcomeres.
The non-contractile element are skeletal muscles that don't contract such as Epimysium,Perimysium and, Endomysium. Contractile muscle contract as a whole muscle instead of single bundles of muscle fibers
Sarcomere
There is no such thing. Were something non-contractile, it would cease to be called a muscle. You probably meant "What is a contractile muscle structure?" or something similar. There are many such answered questions on here.
Contractile cells are the smooth muscle cells of the heart that... contract. They get their signal from the nodes within the heart, which spontaneously fire action potentials (because of leak channels).
Collagen are fibres and are nonliving structure. They are very strong threads and do not contract.