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

Diagnostic evaluation of leukemia, Diagnostic Evaluation   A  study of ...

Diagnostic Evaluation   A  study of complete blood count (CBC) and blood chemistry mainly uric acid levels, is necessary for dignostic evaluation.  Radiologic  studies  are

Ammonia excretion, There is no store for nitrogen-having compounds as there...

There is no store for nitrogen-having compounds as there is for carbohydrate (glycogen)   or lipids (triacylglycerol).  Thus nitrogen ingested in excess of what is required through

Horse diseases-horse-pox, Horse-pox Horse pox is a benign disease chara...

Horse-pox Horse pox is a benign disease characterized by the typical pox lesions on the lower limbs or around the muzzle and buccal mucosa. This is a rare disease, caused by a

What is signifying by concentration gradient, Q What is signifying by conce...

Q What is signifying by concentration gradient? Is it correct or not to refer to "concentration gradient of water"? Concentration gradient is the variation of concentration of

Define the biochemical analysis, Biochemical analysis A basic metabolic...

Biochemical analysis A basic metabolic panel measures sodium, potassium, chloride, bicarbonate, blood urea nitrogen (BUN), magnesium, creatinine, and glucose. It also sometimes

Explain gastro-intestinal system, Explain G.I. (Gastro-Intestinal) system? ...

Explain G.I. (Gastro-Intestinal) system? A. Skeletal muscles directly control the movement of substances at the entrance of the G.I. system. B. Smooth muscles control the mo

Etiology of diarrhoea, Etiology   The causes of diarrhoea can be classi...

Etiology   The causes of diarrhoea can be classified as follows:  i)  Infectious causes   Viral  : Rota virus, Norwalk and allied viruses, Enterovirus, Influenza virus,

Explain procedure for preparation of general purpose media, Explain the Pro...

Explain the Procedure for Preparation of General Purpose Media Procedure: Now prepare the media following the steps enumerated herewith: 1. Weigh and dissolve each ingredien

What is asymmetric carbon atom, Asymmetric carbon atom   : a carbon atom at...

Asymmetric carbon atom   : a carbon atom attached with four different groups or atoms.

Fundamental structure of a virus, Q. What is the fundamental structure of a...

Q. What is the fundamental structure of a virus? Viruses are constituted of genetic material RNA or DNA covered by a protein capsule also known as a capsid. Some viruses, like

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