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

Animal classification, Explain metachrosis in frogs? How it is different fr...

Explain metachrosis in frogs? How it is different from change of skin colour of chemleon?

Is a gene a triplet of consecutive dna nucleotides, Is a gene a triplet of ...

Is a gene a triplet of consecutive DNA nucleotides? A gene is not a triplet of DNA nucleotides with their respective nitrogen-containing bases, like AAG or CGT. The nucleotide

Viral diseases of domestic animals, Cattle and buffalo diseases Rinde...

Cattle and buffalo diseases Rinderpest: Rinderpest is the most destructive of the virus diseases of cloven-footed animals, viz. cattle, buffaloes, sheep, goats, pigs and wil

Identify the abnormal protein, Identify the abnormal protein and state how ...

Identify the abnormal protein and state how the abnormal protein affects the function of the tissue.

Evolution, species dynamicsresemble what

species dynamicsresemble what

Coelentrata, Classification of coelentrata upto sub classes

Classification of coelentrata upto sub classes

Entropy, ENTROP Y - Transfer of energy takes place from high energy...

ENTROP Y - Transfer of energy takes place from high energy level to low energy level. Rudol f clausius gave this term. During it there is collision of particles, r

Measures of evenness, Measures of Evenness The maximum Shannon-Wiener i...

Measures of Evenness The maximum Shannon-Wiener index for a given number of species can be calculated as: The minimum Shannon-Wiener index for a given data set can be c

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