Overview
This lecture covers the anatomy and functions of the human ear, focusing on the outer, middle, and inner ear structures, their roles in hearing, and key terminology.
Structure of the Ear
- The ear has three main regions: outer ear, middle ear, and inner ear.
- The pinna (outer ear) traps sound waves and directs them into the ear canal.
- The ear canal channels sound waves to the tympanic membrane (eardrum).
- The tympanic membrane vibrates in response to sound, starting the hearing process.
Middle Ear Components and Functions
- The middle ear contains three tiny bones called ossicles: hammer, anvil, and stirrup.
- Ossicles amplify sound, making it louder and clearer by transferring vibrations from the large tympanic membrane to the smaller inner ear structures.
- Ossicles convert sound waves into mechanical movement and transfer these vibrations to the inner ear.
- The Eustachian tube connects the middle ear to the back of the throat and maintains pressure in the ear.
- When blocked, the Eustachian tube can cause discomfort and affect hearing.
Inner Ear Components and Functions
- The inner ear contains the cochlea, a snail-shaped structure that converts mechanical movements into electrical impulses sent to the brain.
- The oval window is a membrane that receives vibrations from the last ossicle and transmits them into the cochlea.
- The round window allows excess sound energy to dissipate from the cochlea.
- The vestibular apparatus in the inner ear is responsible for balance and posture.
Key Terms & Definitions
- Pinna — Outer part of the ear that traps and directs sound waves.
- Ear canal — Tube carrying sound from pinna to the tympanic membrane.
- Tympanic membrane — Eardrum; membrane that vibrates with sound.
- Ossicles — Three small bones (hammer, anvil, stirrup) that amplify sound.
- Eustachian tube — Tube maintaining ear pressure by connecting to the throat.
- Oval window — Membrane at the entrance of the cochlea receiving ossicle vibrations.
- Round window — Membrane allowing sound dissipation in the cochlea.
- Cochlea — Inner ear structure converting vibrations into electrical impulses.
- Vestibular apparatus — Inner ear structure responsible for balance and posture.
Action Items / Next Steps
- Review upcoming videos for more details on cochlea and vestibular apparatus.
- Check the grade 12 playlist for latest ear structure and function lessons.