The balancing organ of the ear is composed of two main structures: the semicircular canals and the utricle.

1. Semicircular Canals:
The semicircular canals are three fluid-filled tubes located within the inner ear. They are arranged perpendicular to each other and are responsible for detecting rotational movements of the head. Each canal is filled with a fluid called endolymph, which moves in response to head movements. When the head rotates, the movement of endolymph within the canals stimulates hair cells, which are sensory receptors located in the inner ear. These hair cells convert the mechanical movement into electrical signals, which are then transmitted to the brain for interpretation.

2. Utricle:
The utricle is another structure within the inner ear that plays a crucial role in balance. It is a small, sac-like structure that contains a fluid called endolymph. The utricle is responsible for detecting linear movements and changes in head position relative to gravity. It contains hair cells that are sensitive to the movement of the endolymph. When the head moves in a straight line or changes position, the movement of the endolymph causes the hair cells to bend, generating electrical signals that are sent to the brain.

3. Function:
The semicircular canals and the utricle work together to provide information about the position and movement of the head, which is essential for maintaining balance. The information from these structures is integrated with inputs from other sensory systems, such as vision and proprioception, to ensure accurate perception of the body's position in space. This information is then used by the brain to initiate appropriate motor responses to maintain balance and coordinate movements.

In conclusion, the balancing organ of the ear consists of the semicircular canals and the utricle. These structures detect rotational and linear movements of the head, respectively, and play a crucial role in maintaining balance.