Through which sequence are sound vibrations conducted from the tympanic membrane to the inner ear?
A Malleus → incus → stapes → oval window
B Incus → malleus → stapes → round window
C Stapes → incus → malleus → oval window
D Malleus → stapes → incus → round window
Solution
Correct Answer: Option A
The correct sequence through which sound vibrations are conducted from the tympanic membrane to the inner ear is:
Malleus → Incus → Stapes → Oval Window.
- Sound waves first cause the tympanic membrane (eardrum) to vibrate.
- These vibrations are then transmitted to the ossicles, which are three small bones located in the middle ear.
- The first bone to receive the vibrations is the malleus, which is directly attached to the tympanic membrane.
- The malleus transmits the vibrations to the incus, which in turn passes them to the stapes.
- The stapes connects to the oval window, a membrane-covered opening to the inner ear.
- The stapes acts like a piston, transmitting the vibrations into the fluid-filled cochlea of the inner ear, where the mechanical vibrations are converted into nerve impulses for the brain to interpret as sound.
- It is important to note that the round window is a separate membrane that serves as a pressure release for the fluid movement within the cochlea and is not part of the ossicular chain conducting sound vibrations.
Hence, the correct anatomical and physiological pathway for sound conduction is:
Tympanic Membrane → Malleus → Incus → Stapes → Oval Window → Inner Ear.
Reference: Gray's Anatomy, 41st Edition, Volume 3: The Ear, Chapter 37 / Page 1142