The Balance Organ
The spirit level inside your ear
Close your eyes and stand still. You can do it â but how do you know which way is up? Deep in each ear is a balance organ full of fluid that acts like a spirit level for your whole body.
The vestibular system in the inner ear
Real anatomy picture coming soon
Real anatomy photo spot: three semicircular canals and the utricle/saccule, the balance organ
Three looping canals
Your inner ear has three semicircular canals â loops of tube, one for each direction of space: nodding, tilting, and spinning. Each loop is full of fluid. When your head moves, the fluid sloshes, bending tiny hairs that send a signal to your brain: 'We're turning!'
The spirit level
Beside the loops sit two little pouches â the utricle and saccule â with crystals sitting on a bed of hairs. Like a spirit level, they sense whether your head is tilting. Together with your eyes and your proprioceptors (Lesson 45), this system keeps you upright. Spinning makes the fluid swirl even after you stop â that's why the world keeps turning and you feel dizzy!
Mr. Bones says: I'm a fictional skeleton, not a doctor! This is for learning and fun. If anything hurts, stop and tell a grown-up you trust.
