BIO210Y5 Lecture Notes - Lecture 11: Ear Canal, Bony Labyrinth, Semicircular Canals
Document Summary
The external ear is the key to how sound is directed towards the middle ear called the auricle: has an external acoustic meatus, composed of cartilage. The middle ear has the tympanic membrane that"s attached to 3 middle ear ossicles (small bones: malleus, incus, and stapes. Stapes is evolutionarily the oldest structure important for how the sound wave is translated into pressure waves of the fluid in your inner ear. The oval window is the boundary to the inner ear. The muscles are there to move the stapes in a certain direction: attaches to the wall of the tympanic cavity. First malleus moves when the tympanic membrane moves. Receptor cells are in the hair cells: important for balance and hearing. They are mechanoreceptors there are different types: kinocilia (balance) and stereocilia (interpreting sound wave signals) The two types of hair cells are sitting in the fluid called endolymph.
