Home » Articles » Health » Body Parts » The Human Ear » Anatomy of the Ear » Tympanic Membrane (Ear Drum)

Tympanic Membrane (Ear Drum)

February 14, 2012 928 No of hits
0
Tympanic Membrane (Ear Drum)

Sounds entering the auditory canal impact the tympanic membrane (TM), or ear drum as it is commonly known, causing it to vibrate. The TM is very small, only 9 mm in diameter. It is constructed in three layers. The outer or lateral layer is skin continuous with that of the auditory canal. The inner or medial layer of the TM is mucous membrane that is continuous with the tympanic cavity of the middle ear. In between the outer and inner layers of the TM is a layer of fibrous tissue (lamina propria) that gives the TM its stiffness and tension. The tension of TM is adjusted by the tensor tympani muscle, the larger of the two muscles located in the middle ear (the other being the stapedius muscle). This very small muscle is attached to the manubrium (handle) of the malleus (hammer) bone.

The vibration of the TM is transformed into mechanical vibrations by the ossicular chain creating a leverage effect that increases the efficiency of the transmission of sound energy and increases the sound pressure at the oval window located on the cochlea by approximately 30 decibels. This increase in sound pressure is due to the transfer of pressure from the larger area of the TM to the much smaller area of the oval window located. The increase is needed to overcome the natural resistance (impedance) to the transmission of the sound vibrations by the fluids contained in the inner ear.

The tympanic membrane is susceptible to damage caused by perforation, infection, etc. When this occurs, the transmission of sound is not necessarily ended, but is markedly diminished. Care should be exercised when putting objects such as Q-tips, long fingernails, paperclips, etc. into the auditory canal.

Tags:   Tympanic Membrane (Ear Drum)   Tympanic membrane (TM)   Stapedius muscle   Ossicular chain  

Group

Tympanic Membrane (Ear Drum)

Photo

Ni_271_192 Be the first to add photo

Discussion topics

Start new topic
1_s_ab45ca8ce8fb1beb
0 Comments

Sounds entering the auditory canal impact the tympanic membrane (TM), or ear drum as it is commonly known, causing it to vibrate. The TM is very small, only 9 mm in diameter. It is constructed in three layers. The outer or lateral layer is skin continuous with that of the auditory canal. The inner...

By: Richard Martine Created 18 months ago

Add New Comment

You've decided to leave a comment. That's fantastic! Let's have a personal and meaningful conversation. Thanks for dropping by!

Groups

Related Groups

Topic

Related Group Topics

  • Tympanic Membrane (Ear...
    Tympanic Membrane (Ear Drum)
    By : Richard

    Sounds entering the auditory canal impact the tympanic membrane (TM), or ear drum as it is commonly known, causing it to vibrate. The TM is very small, only 9 mm in diameter. It...

    Read More »
  • Myringoplasty
    Myringoplasty
    By : Richard

    Myringoplasty is an ear surgery to repair a hole in the eardrum, or tympanic membrane, with a graft, so the patient's hearing might improve and to significantly decrease the...

    Read More »
  • Anatomy of the Ear
    Anatomy of the Ear
    By : Richard

    The ears are the sensory organs that make up both the auditory system and the vestibular system. The auditory system involves hearing, or audition--the interpretation of sound...

    Read More »

Album

No photo album for this group

Photo

No Photos availabe for this.

Most Rated

Most Commented

  • Religion
    Religion
    Religion

    Merriam Webster defines religion as "service and worship of God or the supernatural" or...

    Read More »
  • Bruckner, Anton
    Bruckner, Anton
    Bruckner, Anton

    Joseph Anton Bruckner (1824-1896) was an Austrian composer whose classical career began later...

    Read More »
  • Skeletal System
    Skeletal System
    Skeletal System

    The skeletal system provides support to your body, protects your internal organs and works...

    Read More »

Most Viewed