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

Define ascorbic acid content of white blood cells, Define Ascorbic acid con...

Define Ascorbic acid content of white blood cells? The ascorbic acid content of white blood cells and platelets is a good index of the tissue levels of ascorbic acid. The level

Eyes, Are dogs colour blind

Are dogs colour blind

Define the concept of food security, Define the Understanding the Concept o...

Define the Understanding the Concept of Food Security? Food security may be defined as a physical and economic access by all people, at all times, to sufficient food to meet th

Protein electrophoresis - measuring genetic diversity, Q. Protein electroph...

Q. Protein electrophoresis - Measuring Genetic Diversity? This method is now being used to measure genetic diversity. Genes contain the information required to produce enzymes

Explain about oral glucose tolerance test, Q. Explain about Oral Glucose To...

Q. Explain about Oral Glucose Tolerance Test? This is most commonly used diagnostic test particularly for identifying new and ‘at risk' individua1s.Thi.s test is carried out af

Uses of microbes in industry-amino acids and vitamins, Normal 0 ...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

What is embryonic origin of the nervous system in vertebrate, How does the ...

How does the embryo turn from gastrula into neurula? How is the neural tube formed? What is the embryonic origin of the nervous system in vertebrates? The neurula stage is divi

Non migrainous vascular headaches, Non Migrainous Vascular Headaches Th...

Non Migrainous Vascular Headaches This headache associated with dilation of the cranial arteries and can be induced by a wide variety of diseases and conditions. The most commo

Permanent partial disability - injury from an accident, Permanent Partial D...

Permanent Partial Disability - Injury from an Accident Permanent partial disability restrains the worker by doing the job he has been doing. He recovers from the injury in th

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