Balance (Equilibrium)
Biological system that enables individuals to know where their bodies are in the environment and to maintain a desired position. Normal balance depends on information from the in the , from other senses such as sight and , and from movement.
About the Body’s Balance System
The is a sensory for picking up sound waves and allowing us to hear. But it is also essential to our sense of balance: inside of the is the (the organ of balance). It is made up of three fluid-filled canals — the — as well as the , two sacks also filled with fluid.
Each of the semicircular canals leads to a small chamber that has small hairs cells in it. These chambers are also called ampullae. When the head moves, the hairs are pulled by the fluid into one or more of the semicircular canals. The hairs sense this movement and then send nerve signals to the brain.
Each of the three semicircular canals is responsible for a specific direction of head movement: one registers when the head nods up or down, one when the head rotates to the right or left, and one when the head turns sideways.
The otolith organs, which are the other part of the vestibular system, are two pouches that are also filled with fluid. They sit sideways below the semicircular canals and have a similar function. These two pouches are also lined with small hairs. Small crystals attached to the hairs move through the fluid when the head tilts…