University:
Binghamton University
Course:
BIOL 313 | Cellular Neurobiology
Academic year:

2024
Views:

132

Pages:

2
Author:

CrystalMintah

Cellular Neurobiology BIOL 313 November 13th, 2024: Organized Notes on Sound and Hearing Structure of the Ear 1. Outer Ear: ● Includes the pinna, which: ● Helps localize sound. ● Amplifies sound, especially within the range of 3,000-4,000 Hz (critical for human hearing). 2. Middle Ear: ● Contains three tiny bones (ossicles: malleus, incus, stapes). 3. Inner Ear: ● Houses the cochlea: ● A fluid-filled, spiral-shaped tube with flexible windows at one end. ● The stapes pushes on the oval window, creating waves in the cochlear fluid. ● Fluid waves travel through the cochlea, pushing back at the round window. Cochlear Structure 1. Chambers: ● Scala vestibuli: Receives pressure waves from the oval window. ● Scala tympani: Fluid pressure exits through the round window. ● Scala media: Contains sensory cells (hair cells). 2. Flexible Divisions: ● The basilar membrane separates the scala tympani and scala vestibuli. ● Supports the hair cells, which are critical for sound transduction. Sound Processing in the Cochlea 1. Basilar Membrane Movement: ● High frequencies: Maximal movement near the base (close to the oval and round windows). ● Low frequencies: Maximal movement near the apex of the cochlea. ● Intermediate frequencies: Distributed along the membrane in a tonotopic organization. ●