Including all of the relevant anatomical structures explain how we sense spinning in a chair

We sense spinning in the chair or any change in our balance because of the presence of an organ found within the ear. This organ is known as the cochlea. The cochlea is snail-like structure within the ear that contains hair-like and semi-fluid material that is sensitive to movements. As the chair moves, the cochlea senses this and adjusts the fluid-like materials within the ear to help us become balanced again.