Describe what happens when a muscle contracts

During contraction, the filaments slide past he thick filaments, shortening the sarcomere. The thick and thin filaments do the actual work of a muscle, and the way they do this is pretty cool. Thick filaments are made of a protein called myosin. At the molecular level, a thick filament is a shaft of myosin molecules arranged in a cylinder. Thin filaments are made of another protein called actin. The thin filaments look like two strands of pearls twisted around each other.

Cis the

Air goes past the epiglottis and into the trachea when you breathe in. from there, it goes to your vocal cords in the larynx until it reaches the bronchi. from the bronchi, air passes into each lung.