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

Acute mitral regurgitation-mitral regurgitation, Acute Mitral Regurgitation...

Acute Mitral Regurgitation :  This may be caused by chordal rupture, infective endocarditis or acute myocardial infarction. In acute myocardial infarction, one of the papilla

Which kind of chemical bond maintains the pairing, Q. Which kind of chemica...

Q. Which kind of chemical bond maintains the pairing of each chain in the DNA molecule? To form the DNA molecule, purine bases bind to pyrimidine bases by intermolecular bonds

What is the probability that the child will have pku, PKU is a recessive di...

PKU is a recessive disorder. Suppose two people who were heterozygous for PKU married and had a child. What is the probability that the child will have PKU?

Why ups is so important to health practitioners, Give a short explanation o...

Give a short explanation of what UPS really means and why it is so important to health practitioners and consumers/patients.

Explain procedure for gram staining of bacterial cultures, Explain Procedur...

Explain Procedure for Gram Staining of Bacterial Cultures? Now carry out the exercise following the steps enumerated herewith. 1. Prepare bacterial smear on a clean, non-gre

Salmonellosis in poultry, Salmonellosis in poultry A wide variety of se...

Salmonellosis in poultry A wide variety of serovars are prevalent among chicken, turkeys, ducks and geese. The poultry is an important reservoir of salmonellae. The common dise

Show the explanation passes a chi square test, You work with petunias and y...

You work with petunias and you have identified a single gene that causes their flowers to either be all pigmented (solid), or streaked with white. Depending on the genotype of this

Differentiation of tissues - root apex, Differentiation of Tissues - Root A...

Differentiation of Tissues - Root Apex New cells generated from the divisions of meristematic cells start expanding and differentiating further. Epidermis, cortex and stele a

What is the primary structure of a protein, What is the primary structure o...

What is the primary structure of a protein? What is the significance of the primary structure? The primary protein structure is the linear sequence of amino acids that form 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