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

What is the objectives of neuropsychological assessment, What is the Object...

What is the Objectives of Neuropsychological assessment?   Define and describe neuropsychological assessment; Elucidate the neuropsychological methodology for assessing i

Use of genital herpes in pregnancy, Use of genital herpes in pregnancy ...

Use of genital herpes in pregnancy Although acyclovir is not approved for treatment of pregnant women, its use during pregnancy has not been associated with an increased risk

Write the meaning of hypoglycemia, Q. Write the meaning of Hypoglycemia? ...

Q. Write the meaning of Hypoglycemia? Hypoglycemia is a Greek term: hypo -meaning less; glyc - means sweet; and emia - means "of the blood". It is a condition in which less th

Describe wide split s in details, Describe Wide Split S in details? It ...

Describe Wide Split S in details? It is a persistent split that widens on inspiration to at least 60 msec. May be due to delay in P, e.g. RBBB or due to early A, as occasionall

Thyroid-stimulating hormone blood level in hypothyroidism, Q. What happens ...

Q. What happens to the TSH (thyroid-stimulating hormone) blood level in hypothyroidism? Why is there enlargement of the thyroid in the endemic goiter disease? When there is low

Show the energy pyramids, Q. Can the amount of available energy in a given ...

Q. Can the amount of available energy in a given trophic level be larger than the available energy in inferior trophic levels? What does that condition means to the conformation of

Glucose-6-phosphate to glucose, Glucose-6-phosphate to Glucose Glucose...

Glucose-6-phosphate to Glucose Glucose-6-phosphate to Glucose : Glucose-6-phosphate  is converted to glucose  by glucose-6-phosphatase which is present in intestine, liver and

Describe chemical changes in fruits and vegetables, Describe Chemical chang...

Describe Chemical changes in fruits and vegetables The detailed chemical changes that occur when fruits and vegetables are boiled in water or steamed, canned, dried or frozen,

Explain the storage of vitamin a, Explain the Storage of vitamin A? The...

Explain the Storage of vitamin A? The primary organ for storage of vitamin A is the liver. Reserves are found in the stellate cells, as mentioned above. The average liver weigh

What are toxic effects of lectins or haemagglutinins, What are toxic effect...

What are toxic effects of lectins or haemagglutinins? Well, these can cause growth inhibition in animals and diarrhoea, nausea, bloating and vomiting in case of human beings. W

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