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

Fission - asexual reproduction, Normal 0 false false false ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

How does the swim bladder of fishes work, Q. How does the swim bladder of f...

Q. How does the swim bladder of fishes work allowing fishes to control their depth under water? From Hydrostatics it is known that an object does not sink if its density is les

Female drosophila with singed bristles, A female Drosophila with singed bri...

A female Drosophila with singed bristles is crossed to a male with sepia (dark brown) eyes. In the F1, all females are wild-type and all males have singed bristles. F1 males and fe

Structures shared by every chordate, Q What are the three structures shared...

Q What are the three structures shared by every chordate that characterize the group? All beings of the phylum Chordata have branchial clefts in the pharynx in some species pre

What are the three main types of passive transport, What are the three main...

What are the three main types of passive transport? The three main kinds of passive transport are a)  simple diffusion, b)  osmosis and c)  Facilitated diffusion. C

Two dimensional gene scanning method, Two dimension gene scanning technique...

Two dimension gene scanning technique is a high resolution system for finding of mutational variants in multiple genes. This method is on the basis of combination of extensive poly

Explain prosthetic device infections, Explain Prosthetic device infections ...

Explain Prosthetic device infections Some infectious disease specialists recommend antimicrobial prophylaxis before process in patients with vascular grafts or orthopedic pros

Two homologous human chromosomes, Two homologous human chromosomes have the...

Two homologous human chromosomes have the following structure: --A--B-.-C--D--E--F--G--H--I--J-- --A--D--C-.-B--E--F--G--J--I--H-- where the letters represent genetic markers and t

What are the different radiographic techniques, Q. What are the different r...

Q. What are the different radiographic techniques used for assessing osseointegration? The different radiographic techniques used to assess osseointegration prior to stage 2 su

What do you mean by amphibians of the plant world, Q. Why can the bryophyte...

Q. Why can the bryophytes be considered the "amphibians of the plant world"? Like adult amphibians, the bryophytes live in the terrestrial environment but they depend on water

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