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

How is the concentration of drugs in human plasma defined, Some drugs bind ...

Some drugs bind extensively to plasma proteins (Warfarin binds 99%) while others have virtually no binding. Extraction depends on the type of drug - there are dissimilar standar

What are the alleles of a gene, What are the alleles of a gene? The Dip...

What are the alleles of a gene? The Diploid individuals have paired chromosomes. For instance in humans there are 23 pairs of chromosomes totaling 46 chromosomes. Every pair co

Describe plasmid functions to bring about resistance, E. coli strains conta...

E. coli strains containing the plasmid pAMP are resistant to ampicillin. Describe how this plasmid functions to bring about resistance.

Controlling introduction of alien species, Controlling Introduction of Alie...

Controlling Introduction of Alien Species As you know the alien species can cause the existing population to decrease or even become extinct. The individuals of alien species

What is action mechanism of antibiotic penicillin, Q. What is action mechan...

Q. What is action mechanism of antibiotic penicillin? Penicillin, discovered by the Scottish doctor Alexander Fleming in 1928, is a drug that inhibits enzymes essential for the

Define the thin and thick filaments of a sarcomere, When the overlap betwee...

When the overlap between the thin and thick filaments of a sarcomere in a skeletal muscle is decreasing, A. the total length of the I band is increasing in the sarcomere. B.

DNA, DNA TRANSLATION AND TRANSCRIPTION

DNA TRANSLATION AND TRANSCRIPTION

The identity and amounts of elements in the molecule, If the chemical formu...

If the chemical formula of a substance is C17 H 31 COOH, what can you tell about the identity and amounts of elements in the molecule? Can someone please explain me this?

Determine the method of recombination, Which of the following is a false st...

Which of the following is a false statement regarding the method of recombination or crossing-over? A. Crossing-over takes place during prophase I of meiosis B. Recombinatio

What is peri-implant disease, Q. What is Peri-Implant Disease? The term...

Q. What is Peri-Implant Disease? The term peri-implantitis is used to describe the boneloss around an implant. This may be induced by stress or bacteria or a combination of bot

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