Middle ear, Biology

Assignment Help:

MIDDLE EAR -

  1. Protected by tympanic bone. It's cavity is tympanic cavity.
  2. It is lined by simple cilliated columnar epithelium. It is connected to naso pharynx by Eustachian canal.
  3. Here valve is present, generally closed, during shouting, yawning & swallowing it is opened.
  4. Due to it on both sides of tympanum, pressure of air is equalized. Inflamation of eustachian tube is eutachitis.
  5. Cold may block the eustachian tube & the pressure outside and inside the middle ear do not equalige. So divers and fliers do not work when they have cold. Outside preesure is increases in diving & decresed in flying.
  6. Middle ear is connected to internal ear by fenestra ovalis or oval window and fenestra rotundus or round window.
  7. By fenestra ovalis sound waves enter in to internal ear. By fenestra rotundus sound waves come out if strong.
  8. Between tympanum and fenestra ovalis there is a chain of 3 bones collectively called as ear ossicles.
  9. Three bones are malleus, inchus & stapes. Malleus is hammer shaped attached to tympanum.
  10. Inchus is anvil shaped. Stapes is stirrup shaped, smallest bone with bone marrow.
  11. All bone are articuluted by hinge joint & fixed in position due to their respective ligaments.
  12. These bones are modification of articular, quadrate and hyomendibular.
  13. In frog collumella auris present, which is modification of hyomendibular.
  14. Ear ossicles transmit the vibration from the tympanic membrane to internal ear and also amplify them about 20 times.
  15. Two small muscles tensor tympani and stapedius, joined to malleus and stapes respectively, contract to prevent damage to the dellicate internal ear at the time of loud sound.

Related Discussions:- Middle ear

Metabolism, What is Metabolism ?  The  sum total of vital activities ( ...

What is Metabolism ?  The  sum total of vital activities ( movements , nutrition, growth, respiration, excretion , reproduction, behaviour ,etc.  Is the  life  of a living  bei

Heart failure, It is a clinical syndrome wherein heart fails to pump blood ...

It is a clinical syndrome wherein heart fails to pump blood at a rate required by the tissues of the body or it can do so only with an elevated filling pressure. This may be due to

Tissue, Why lymph is called the middle man of our body?

Why lymph is called the middle man of our body?

Explain the decolourizing agent - stain technique, Explain the Decolourizin...

Explain the Decolourizing Agent - Stain Technique? 95% ethanol is used as a decolourizing agent. It has two functions - (1) It acts as protein - dehydrating agent, and (2

Volvox Colonial Existence, Necessity of interdependence of Volvox organisms...

Necessity of interdependence of Volvox organisms in the colonial existence

Explain chlamydia, Explain Chlamydia  A single 1 g dose of azithromycin...

Explain Chlamydia  A single 1 g dose of azithromycin (Zithromax) or 7 days' treatment with a tetracycline are both effective for treatment of uncomplicated urethral or cervical

What are SOL, What are sols?  A colloidal system in which solid  partic...

What are sols?  A colloidal system in which solid  particles are dispersed in a liquid is referred to as a sol, to distinguish it from a true solution. In a true solution, the

What is extracellular digestion, What is extracellular digestion? Extra...

What is extracellular digestion? Extracellular digestion is that in which food breaking into utile molecules that can be internalized by the cell is completed in the extracellu

The trp operon, The trp (tryptophan) operon which is shown in the figure wi...

The trp (tryptophan) operon which is shown in the figure will have  five  structural  genes  encoding enzymes  for tryptophan  biosynthesis  with an upstream  Ptrp  (trp promoter)

Explain retrograde peri-implantitis, What is retrograde peri-implantitis? ...

What is retrograde peri-implantitis? Retrograde peri-implantitis has been described by Misch as implant failure probably due to bone microfractures caused by premature implant

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd