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

Age-sex distribution, Age-Sex Distribution While studying exponential...

Age-Sex Distribution While studying exponential growth we need to know more than just the birth and death rates because these rates vary with age and sex. Age structure in a

Describe oxidative stress in new cardio-vascular, Describe Oxidative Stress...

Describe Oxidative Stress in New Cardio-vascular Risk Factors ? In the risk conferred by LDL cholesterol, the oxidative modification of LDL plays a central role, because it is

Explain the active transport process, Which of the following is an active t...

Which of the following is an active transport process? A. Net flux of sodium across the plasma membrane via voltage-gated sodium channels. B. Net flux of glucose across the

Antonmy, bone modeling may occur?

bone modeling may occur?

Describe the formation of egg cells from germ cells, Q. Indicating the name...

Q. Indicating the name and respective ploidy of each involved cell how can the formation of egg cells from germ cells be described? The formation of egg cells begins with a ger

Illustrating how neuropsychologists evaluate young children, Illustrating h...

Illustrating how neuropsychologists evaluate young preschool children, older children, youngster adults, and elderly adults. The brain is an evolving organ and functions very

Agro industrial-cobalt, Cobalt Cobalt functions as a component of vitamin ...

Cobalt Cobalt functions as a component of vitamin B12  (cobalamin). Ruminants are not dependent on a dietary source of vitamin B12  because ruminal microorganisms can synthesize B

Do platyhelminthes have an excretory system, Q. Cnidarians and Poriferans d...

Q. Cnidarians and Poriferans do not have excretory systems. Do platyhelminthes have an excretory system? Platyhelminthes have a primitive excretory system made of flame cells

Explain dietary management, Dietary Management The golden  rule  in  th...

Dietary Management The golden  rule  in  the dietary  management  of  ally  fever  is  "feed  the fever". Considering that  enteric (typhoid) fever  is accompanied by anorexia,

Determine the chemical synaptic transmission, During chemical synaptic tran...

During chemical synaptic transmission A. neurotransmitter travels via diffusion in extracellular space. B. there will always be release of neurotransmitter from the postsyna

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