1. Which of the following is composed of myosin protein? A) thick filaments. B) thin filaments. C) Z discs. D) myofilaments. 2. Which of the following is not an important function of the components of the muscular system? A) mechanical protection. B) heat generation. C) vitamin storage. D) movement of organs 3. An example of a posterior trunk muscle is the A) pectoralis major. B) internal oblique. C) rectus abdominus. D) trapezius.

Myosin proteins are responsible for many roles in the body some of which include muscle contraction and other mobility processes in organisms whose cells contain a nucleus and other organelles that are bounded by membranes (eukaryotes). Based on this we can say that thick filaments are composed of myosin protein. The muscular system is composed of muscle fibers whose main job is contractibility. With this in mind it can be said that from the options the only one that makes sense is vitamin storage. An example of a posterior trunk muscle is trapezium; which is responsible for elevating, stabilizing and depressing the scapulae.