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

Hemerythrins - respiratory pigments, Hemerythrins - Respiratory Pigments ...

Hemerythrins - Respiratory Pigments The Hemerythrins are rather rare. They take place in some animals belonging to the minor phyla like the sipunculid worms, some brachiopods,

What are the constituent elements of the blood, Q What are the constituent ...

Q What are the constituent elements of the blood? The blood is made of a liquid and a cellular part the fluid part is called as plasma and in it there are several substances li

Six-membered oxygen-containing ring is referred as, A cyclic hemiacetal wit...

A cyclic hemiacetal with a six-membered oxygen-containing ring is referred to as a(n): Select one: a. aldehyde. b. pyranose. c. ketopentose. d. furanose. e. sorbi

What are respiratory pigments, What are respiratory pigments? What is the r...

What are respiratory pigments? What is the respiratory pigment present in some arthropods? Which is the analogous molecule in humans? Respiratory pigments are molecules able t

Why are transgenics considered a threat, Why are transgenics considered a t...

Why are transgenics considered a threat to the environmental safety? Transgenics can be dangerous to the entire biosphere as the transfer of genes among species may have immed

Explain complex or undefined media, Explain Complex or Undefined Media? ...

Explain Complex or Undefined Media? Here, the exact composition of the medium is not known. It contains some complex components of plant and animal extracts whose exact chemica

Explain marine oils, Marine oils These oils typically contain large amo...

Marine oils These oils typically contain large amounts of long - chain omega-3-polyunsaturated fatty acids, with up to six double bonds and they are usually rich in vitamins A

What do you mean by tuberculosis, Q. What is tuberculosis? How is the disea...

Q. What is tuberculosis? How is the disease transmitted? Is there treatment for tuberculosis? The Tuberculosis is a disease caused by the Mycobacterium tuberculosis bacteria wh

Explain the characteristics of starch granule, Explain the Characteristics ...

Explain the Characteristics of Starch Granule Starch granules, primarily, are made up of amylose (20-30%) and or amylopectin (70-80%) molecules arranged radially. Each granule

Explain techniques for broken instrument removal, Explain Techniques for Br...

Explain Techniques for Broken Instrument Removal Described by Gary Carr Staging platform (cutting in flat surface) a) Create straight line access to separated file using mod

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