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

Tranquillizers - psychological drug dependence, TRANQUILLIZER S - Thes...

TRANQUILLIZER S - These are the drugs that reduce tension and anxiety, bring calmness without inducing sleep. (i) Phenothiazines - These are anti psychotic drugs.

What is name for interruptions for myelin sheath, In most axons, myelin she...

In most axons, myelin sheath is interrupted at intervals of about 1 millimeter or more. These interruptions are known as: a) Collaterals b) Nodes of Ranvier (pron: ron-vee-ay)

Myelinated fibre, Myelinated fibre Axon is a relatively long process (...

Myelinated fibre Axon is a relatively long process (also quite often referred to as nerve fibre) and can be considered as functionally specialised for conduction of excitation

Describe excretory system of annelids, Q. How be able to the excretory syst...

Q. How be able to the excretory system of annelids be described? In each segment (metamere) of the being a pair of complete excretory structures known as metanephridium exists.

Explain the nutrient deficiency disorders, Explain the Nutrient Deficiency ...

Explain the Nutrient Deficiency Disorders? Protein Energy Malnutrition (PEM), iron deficiency anaemia (IDA) and vitamin A deficiency (VAD) are still the major public health pro

Determine the functional structures of the leaf veins, What are the plant t...

What are the plant tissues that constitute the functional structures of the leaf veins? Leaf veins are made of vascular tissues. They are constitute by xylem and phloem that re

Designer meat products, D e s ign e r Meat Products Designer/healt...

D e s ign e r Meat Products Designer/health meat products low in sodium, fat, calories could be produced by incorporating fat replacers, fibers and natural antioxidants an

Explain a reason these cells are used instead of outer body, The cells lini...

The cells lining the inside of the cheek are frequently removed for making observations of basic cell structure. The cells are from stratified squamous epithelium. Explain a reason

Bacterial diseases-sheep and goats, Sheep and goats The disease is rea...

Sheep and goats The disease is readily transmissible to human being from goats, and is known as Malta fever, Mediterranean fever or undulant fever. The chief causal agent is B

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