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

Solitary and colonial forms, Solitary and Colonial Forms Animals may l...

Solitary and Colonial Forms Animals may lead their lives either like individuals or in groups. While they exist as individuals, they are termed as solitary, but if they live i

Illustrate the composition of agar, Composition of agar Agar we learnt ...

Composition of agar Agar we learnt consists of a mixture of agrose and agropectin.  Agrose has a linear polymer structure  consisting of alternating D-galactose and 3,6-anhydro

Explain somatic hybridisation, a) Explain somatic hybridisation? b) De...

a) Explain somatic hybridisation? b) Describe the various steps involved in the process. Mention any two uses of somatic hybridisation

Approximate composition of human tissue, Approximate Composition of Human T...

Approximate Composition of Human Tissue Table gives the approximate composition of human tissue. We all know that carbon, oxygen, hydrogen are present in water and other organ

Counselling diabetic travellers, Counselling Diabetic Travellers The c...

Counselling Diabetic Travellers The counsellor needs to educate a diabetic patient and /or his family members to following issues when such patients plan to travel: ·  Plan

Respirator pigments and breathing, RESPIR A T O R Y PIGMENTS - R...

RESPIR A T O R Y PIGMENTS - Resp. pig. is generally Hb (Fe is attached to globine by chellate bond). In Earthworm Erythroqruorine present. Haemocyanine (Cu) genera

Explain balloon pulmonary valvuloplasty, Pulmonary stenosis is a relatively...

Pulmonary stenosis is a relatively common congenital heart defect. Usually these children with mild to moderate pulmonary stenosis survive into childhood. Since bicuspid pulmonary

Genes and alleles, Genes and Alleles The inheritance of any character c...

Genes and Alleles The inheritance of any character can be studied only when thcre are two contrasting conditions, such as yellow versus green seed colour (as observed by Mendel

Carbohydrate is an organic compound , The Carbohydrate sets are covalently ...

The Carbohydrate sets are covalently attached to various variant proteins to form glycoproteins. Carbohydrates are a shorter percentage of the weight of glycoproteins than of prote

Wind as a medium for dispersal, Wind as a medium for Dispersal Many mic...

Wind as a medium for Dispersal Many microorganisms, fungal spores and bacteria are freely transported over long distances even by moderate winds. In wind pollinated plants, 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