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

Explain therapeutic diets, Explain Therapeutic diets Therapeutic diets ...

Explain Therapeutic diets Therapeutic diets are adaptations of the normal or  regular diet.  In other words, it is a diet  for a patient suffering  from a  specific disease  su

What is genotypical proportion of these gametes, Which is the kind of gamet...

Which is the kind of gamete (for a given trait) produced by a dominant homozygous individual? What is genotypical proportion of these gametes? And what about the recessive homozygo

What is diffusion, What is diffusion? Diffusion is the spreading of sub...

What is diffusion? Diffusion is the spreading of substance molecules from a region where the substance is more concentrated to another region where it is less concentrated. For

Genomic dna libraries , A genomic DNA library is made from the genomic DNA ...

A genomic DNA library is made from the genomic DNA of an organism. For instance, a mouse genomic library could be made by digesting mouse nuclear DNA with a restriction nuclease to

How are the antibodies against the rh factor formed, How are the antibodies...

How are the antibodies against the Rh factor formed? Anti-Rh antibodies are made by humoral immune response. When an Rh- individual makes contact with the Rh factor this is rec

Explain increased fibrinogen levels-thrombogenic factors, Explain Increased...

Explain Increased Fibrinogen Levels and Other Thrombogenic Factors ? Thsombogenesis is an important component in the pathological process of atherosclerosis and so it is not s

Blood be enhanced during vigorous activity, The percentage of oxygen absorb...

The percentage of oxygen absorbed from the air in the lungs is always about the similar, so how can the oxygen supply to the blood be enhanced during vigorous activity? Breathi

List the exact sizes of the fragments of digests, (1)  The 7,893 bp plasmid...

(1)  The 7,893 bp plasmid shown below was digested with a series of restriction enzymes (P = PstI, B = BamHI, S = SalI, X = XbaI). Answer the questions below.  a) Indicate

Discuss about troponin receptor site, Skeletal muscle A. The myosin hea...

Skeletal muscle A. The myosin head is activated (energized) by the conversion of GTP (that is bound to myosin) to GDP and Pi (that are bound to myosin). B. Detachment of the

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