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

Calculate the volume of blood plasma, If one determines the concentration o...

If one determines the concentration of cortisol in the blood plasma to be 10 ugrams/ml and that in a 24 hour period a person excretes 10 mgs of cortisol, calculate the volume of bl

Cartoon, A dialogue and cartoon between haemoglobin and chlorophyll

A dialogue and cartoon between haemoglobin and chlorophyll

Limb regeneration in amphibians, Limb Regeneration in Amphibians In v...

Limb Regeneration in Amphibians In vertebrates, the amphibians particularly the urodeles comprise spectacular power of regeneration. This power of regeneration has made them

Shock, S h o c k It is defined as a generalized acute reduction in ...

S h o c k It is defined as a generalized acute reduction in the perfusion of tissues by which there is oxygen deficiency in the cells. It is characterized by reduction in e

Explain empiric initial therapy, Empiric Initial Therapy  Until suscept...

Empiric Initial Therapy  Until susceptibility results are available, empiric initial treatment consists of a 4-drug regimen of isoniazid, rifampin, pyrazinamide and ethambutol.

The human abo blood type codominant alleles a and b, The human abo blood ty...

The human abo blood type codominant alleles a and b are dominant to O. A man with blood type B and women with blood type A could potentially have children with which of the followi

Vertebrate limb, Vertebrate Limb Earlier we know that how a series of...

Vertebrate Limb Earlier we know that how a series of sequential and coordinated interactions between different cell groups and tissues carry about the construction of a compl

Explain exudate gums, Exudate gums Most exudates gums come from compoun...

Exudate gums Most exudates gums come from compounds  produced when the plant is wounded and these substances seal the wound. Most widely used exudate gum is 'gum Arabic' exuded

What is an example of a hypothesis, What is an example of a hypothesis whic...

What is an example of a hypothesis which may explain why there is not a big representation of the class Reptilia found in polar regions? Beings of the class Reptilia are abunda

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