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

Metestrus - estrous cycle, Metestrus - Estrous cycle This occurs shortly...

Metestrus - Estrous cycle This occurs shortly after ovulation and is intermediate between estrus and diestrus. The period lasts for 10 to 14 hours and mating is usually not perm

What is anti-arrhythmic pacemaker defibrillators, What is Anti-arrhythmic p...

What is Anti-arrhythmic pacemaker defibrillators ? Antiarrhythmic drugs (AADs) are classified according to whether they exert blocking actions predominantly on sodium, potassiu

Gastrulation in chick, Gastrulation in Chick Cleavage in the fertilize...

Gastrulation in Chick Cleavage in the fertilized egg occurs during its passage through the oviduct to cloaca of the hen. By the time it is laid meroblastic cleavage has result

Define vitamin a, Define Vitamin A, Iron and Zinc required for elderly? ...

Define Vitamin A, Iron and Zinc required for elderly? Vitamin A, Iron and Zinc: The recommendation for iron is said to decrease in elderly women. Intake of vitamin E and zinc

In which part of the digestive tube is water is absorbed, Q. In which part ...

Q. In which part of the digestive tube is water is chiefly absorbed? What about the mineral ions and vitamins? Most part of water, mineral and vitamins ions are absorbed by the

Blood pressure with the phenomena of systole and diastole, Q. What is the r...

Q. What is the relation between the maximum and the minimum blood pressure with the phenomena of systole and diastole? A minimum blood pressure is the pressure on the wall of t

Explain waste produced during surgical process, Q. Explain Waste produced d...

Q. Explain Waste produced during surgical process? Some of the waste products produced during a surgical process are dressings, sponges, gloves or other soft material dripping

Which cell count elevates in case of allergy or plastic worm, Which cell co...

Which cell count is likely to be elevated when an individual has an allergy or parasitic worms? a) Red blood cells b) Erythrocyte c) Eosinophil (pron: e-o-sin-o-fill)

Tissue Cells, How is an Epithelial cell made?

How is an Epithelial cell made?

Explain the nutritional and functional role of zinc, Minerals  :-  Zinc ...

Minerals  :-  Zinc Food Source      Meats, cereals.  Nutritional Functional role Essential nutrient: Deficiency produces loss of appetite, growth retardation, skin

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