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

How are nematodes characterized, Q. Nematode identity card. How are nematod...

Q. Nematode identity card. How are nematodes characterized according to examples of representing beings, type of symmetry basic morphology, , germ layers and coelom, digestive syst

Zooology, green gland is excretory organ of which orthopodic phylem

green gland is excretory organ of which orthopodic phylem

Microorganisms, methods of isolating and purifying two useful products from...

methods of isolating and purifying two useful products from microorganisms

Zoology, what are the physical requirements to become a zoologist?

what are the physical requirements to become a zoologist?

Essentiality of phosphorus for growth of microorganism, Define Essentiality...

Define Essentiality of Phosphorus for Growth of Micro-Organism Phosphorus is used in the form of phosphate salt by microorganisms. It is involved in formation of nucleic acids,

What is an accommodation, What is an accommodation? Accommodation is th...

What is an accommodation? Accommodation is the ability of the eye to focus on an object situated at variable distances from the eye. Like a camera, even the eye requires to cha

Blood from a donor is sterile and stored in a sealed bag, Blood from a dono...

Blood from a donor is sterile and stored in a sealed bag, but it is still kept at 4°C. What is the advantage of keeping it at this low temperature?   At 4 °C, enzyme activi

Open and closed type of circulatory systems, Open and Closed Type of Circul...

Open and Closed Type of Circulatory Systems There are two categories of circulatory system found in higher metazoans. In one type the original blastocoel carries on to be the

Explain about the endocrine system, Why is the endocrine system considered ...

Why is the endocrine system considered one of the integrative systems of the body? What is the other physiological system that also has this function? The endocrine system is s

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