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

Role of dietitian in health care, Role of Dietitian in Health Care The ...

Role of Dietitian in Health Care The role of the dietitian has come a long way since the early 1900s. Their role is still unknown to a  lot of people. Some think that dietitian

Explain about the zone electrophoresis, Explain about the Zone Electrophore...

Explain about the Zone Electrophoresis? Zone electrophoresis which was introduced about a decade later describes the migration of charged macromolecules in a porous supporting

Explain electron microscope, Explain Electron Microscope? Electron micr...

Explain Electron Microscope? Electron microscopes have higher magnification and resolving power than light microscopes.  What do we mean by magnification and resolving power? W

Explain Isolated soybean proteins, Explain ISP The specification of th...

Explain ISP The specification of the Association of American Feed Control Officials, Inc. (AAFCO) defines ISP as "Major proteinaceous fraction of soybeans prepared from dehulle

Polyphyletic theory, Please I need short notes on polyphylrtic theory

Please I need short notes on polyphylrtic theory

Transcription of eukaryotic protein coding genes, 1. The transcription and ...

1. The transcription and replication of DNA requires a multitude of protein complexes a. Describe the events that occur during the initiation of transcription of eukaryotic prot

Define distribution of food products – public nutrition, Define Distributio...

Define Distribution of Food Products - Public Nutrition? We learnt earlier that we have buffer stocks of food grains in our country. These stocks do help to combat acute transi

What are the results of prosthetic valve endocarditis, What are the Results...

What are the Results of prosthetic valve endocarditis? The hospital mortality for valve replacement for endocarditis varies between 4- 30 per cent. Operative mortality is highe

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