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

Viral diseases, Nature of viral diseases Viral diseases are manifested...

Nature of viral diseases Viral diseases are manifested in acute, sub-acute or chronic forms, as frank clinical cases or as latent infections, some of which are fatal. These di

Evolution , What benefits led to natural selection of a two-circuit pump f...

What benefits led to natural selection of a two-circuit pump function of the heart a) One circuit to go from the heart to the body and one from the heart to the lungs b) One cir

Define japanese criteria for functional foods, Define Japanese criteria for...

Define Japanese criteria for functional foods? The Japanese criteria for functional foods include: They are food (not capsules, pills/powder) on the basis of naturally o

What do you mean by echinodermata, Q. What do you mean by Echinodermata? ...

Q. What do you mean by Echinodermata? You will recall that Pliylum Echinodermata includes spiny skinned animals which are exclusively marine (Gr, echinus : spiny; derma: ski

What chromosome condition is created, Following fertilization by a normal s...

Following fertilization by a normal sperm, what chromosome condition is created?

What is the molecular composition of hemoglobin, What is the molecular comp...

What is the molecular composition of hemoglobin? Does the functionality of hemoglobin as a protein depend upon its tertiary or upon its quaternary structure? Hemoglobin is a mo

What is the association between sunrays and vitamin d, Q. What is the assoc...

Q. What is the association between sunrays and vitamin D? Vitamin D or calciferol is synthesized in the skin by the action of the ultraviolet range of sunrays upon precursor mo

Define regulation of amino acid levels in the blood, Define Regulation of a...

Define Regulation of amino acid levels in the blood? Regulation of amino acid levels in the blood: Vitamin D helps to prevent loss  of amino acids through the kidney and thus

Explain about the terms - bursae and captacula, Explain about the terms - b...

Explain about the terms - bursae and captacula? Paired water-filled sac located at base of each arm of a brittle star. Cilia in bursae circulate water. Its surface is significa

Define limitations of agar syringe or agar sausage method, Define Limitatio...

Define Limitations of Agar Syringe or Agar Sausage Method? (i) It is applicable to surfaces with low contaminants. (ii) Problem of spreading colonies may occur. (iii) Col

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