Anatomy of the Human Ear

Structure of the Ear

• The ear is divided into three main parts: outer ear, middle ear, and inner ear.
• The outer ear consists of:
  • Pinna (visible part of the ear)
  • Auditory canal (connects pinna to eardrum)
• The middle ear consists of:
  • Eardrum (tympanic membrane)
  • Ossicles (three small bones: malleus, incus, and stapes)
  • Eustachian tube (connects middle ear to back of throat)
• The inner ear consists of:
  • Cochlea (hearing organ)
  • Vestibule (balance organ)
  • Semicircular canals (balance organ)

Functions of the Ear

• Hearing: sound waves are converted into electrical signals that are transmitted to the brain.
• Balance: the inner ear helps to maintain balance and equilibrium.
• Sound localization: the ear helps to locate the source of sounds.

Mechanism of Hearing

• Sound waves enter the outer ear and travel through the auditory canal to the eardrum.
• The eardrum vibrates, causing the ossicles to vibrate.
• The vibrations are transmitted to the cochlea, where they are converted into electrical signals.
• The electrical signals are transmitted to the auditory nerve and then to the brain, where they are interpreted as sound.

Disorders of the Ear

• Hearing loss: can be caused by damage to the ear or auditory nerve.
• Ear infections: can occur in the middle ear (otitis media) or outer ear (otitis externa).
• Vertigo: a balance disorder caused by problems in the inner ear or brain.

Structure of the Ear

• The ear consists of three main parts: outer ear, middle ear, and inner ear.

Outer Ear

• Comprises of pinna (visible part of the ear) and auditory canal (connects pinna to eardrum).

Middle Ear

• Comprises of eardrum (tympanic membrane), ossicles (three small bones: malleus, incus, and stapes), and Eustachian tube (connects middle ear to back of throat).

Inner Ear

• Comprises of cochlea (hearing organ), vestibule (balance organ), and semicircular canals (balance organ).

Functions of the Ear

• Hearing: sound waves are converted into electrical signals transmitted to the brain.
• Balance: the inner ear helps maintain balance and equilibrium.
• Sound localization: the ear helps locate the source of sounds.

Mechanism of Hearing

• Sound waves enter the outer ear and travel through the auditory canal to the eardrum.
• Eardrum vibrates, causing the ossicles to vibrate.
• Vibrations are transmitted to the cochlea, where they are converted into electrical signals.
• Electrical signals are transmitted to the auditory nerve and then to the brain, where they are interpreted as sound.

Disorders of the Ear

• Hearing loss: can be caused by damage to the ear or auditory nerve.
• Ear infections: can occur in the middle ear (otitis media) or outer ear (otitis externa).
• Vertigo: a balance disorder caused by problems in the inner ear or brain.