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 implant site evaluation, Implant site evaluation 1. Ridge:...

Implant site evaluation 1. Ridge: Total buccolingual width of the ridge- the thickness of the soft tissue ( bucally +lingually)= Buccolingual width of the bone. There shou

Explain difference between fats and oils, Explain the molecular difference ...

Explain the molecular difference between fats and oils. How do the differences affect their physical properties?

What is weaning from mechanical ventilation, What is Weaning from Mechanica...

What is Weaning from Mechanical Ventilation? It is crucial to get the timing just right as to when to discontinue mechanical ventilation and extubate. If too early, this might

Hydralazine, Hydralazine is a potent arteriolar dilator and markedly increa...

Hydralazine is a potent arteriolar dilator and markedly increases cardiac output in patients with congestive heart failure. However, as a single agent, it has not been shown to imp

How successful are you at synthesizing genes, How successful are you at syn...

How successful are you at synthesizing genes with really high G/C content? A: We have an extremely low failure rate, which is about one out of five thousand or ten thousand gen

Oogenesis, - Oogenesis involves the formation of haploid cells from an orig...

- Oogenesis involves the formation of haploid cells from an original diploid cell, called a primary oocyte, through meiosis. - The female ovaries contain the primary oocyte. The

Explain food applications of gum karaya, Explain Food Applications of gum k...

Explain Food Applications of gum karaya The water absorbing and water-holding capacity of Karaya, together with an excellent acid compatibility made it suitable for its use

Aerobic based water treatment, Aerobic Based Water Treatment: Waste wat...

Aerobic Based Water Treatment: Waste water provides organic materials and inorganic nutrients to river waters; this is known as eutrophication. This promotes microbial and plan

Muscular force, 2.?In order to increase muscular force production, muscular...

2.?In order to increase muscular force production, muscular contractions may be modulated in two ways. Explain.

#classification of parasitic protozoa.., most recent classification of para...

most recent classification of parasitic protozoa with its general characters

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