External ear, Biology

Assignment Help:

EXTERNAL EAR -

  1. It is an oval shaped, some what funnel like, skin covered flap of elastic cartilage and muscles.
  2. It's outer stiff ridge is called hellix. Lower flexible lobe is lobule. Cavity is known as auricle or Concha.
  3. It collects sound waves and direct them to canal i.e. external auditory meatus.
  4. It is trumpet shaped in rabbit. Situated on lateral side of head part.
  5. Immovable as oticularis muscles are vestigeal, movable in rabbit.
  6. External auditory meatus run up to tympanum. It is 'S' shaped tube to prevent hard objects hitting the tympanum directly, in rabbit tube is long & straight.
  7. Canal is supported by elastic cartilage in the outer portion & by temporal bone in the inner portion.
  8. Outer region of canal bears hair to cheek dust particle.
  9. Inner region consists of ceruminous gland or wax gland to secreate cerumen or ear wax to protect lining of meatus & tympanum.
  10. Pinnae absent in platypus, whales seal, walrus & sea cow etc.
  11. Tympanum or tympanic membrane is thin, oval, tightly stretched on a cartilage i.e. Annular tympanicus.
  12. It is composed of connective tissue with fibres radiating from the central region called umbo.
  13. It's external part is ectodermal, middle part is mesodermal & inner part is endodermal in origin.

2348_man ear structure.png

Ear of Man

742_rabbit ear.png

Ear of Rabbit


Related Discussions:- External ear

Can you define musculoskeletal system, Q. Which are the organs that are par...

Q. Which are the organs that are part of the musculoskeletal system? The key tissues and organs that are part of the musculoskeletal system in humans are the cartilages, the mu

Determine guidelines for planning balanced diets for elderly, Determine Gui...

Determine Guidelines for Planning Balanced Diets for Elderly? The key element in planning diets for the elderly should be nutrient-based dietary guidelines, in order to reduce

Causes of extinction, CAUSES OF EXTINCTION - 1 .       HUNTING - ...

CAUSES OF EXTINCTION - 1 .       HUNTING - Man started hunting wild animlas for food and safety trade and fun. It may be subsistence hunting, commercial hunting and sp

Which foods are used by microorganisms for energy, Q. Which Foods are used ...

Q. Which Foods are used by Microorganisms for Energy? The carbohydrates, especially the sugars, are most commonly used as an energy source, but other carbon compounds can also

What do you mean by borrowed materials, Q. What do you mean by Borrowed Mat...

Q. What do you mean by Borrowed Materials? For the study of as much relevant material as possible the material is obtained on loan. Borrowed specimens benefit the' lending inst

Nutrition, prove oxygen is produced during photosynthesis in the presence o...

prove oxygen is produced during photosynthesis in the presence of light

Left atrio-ventricular, The left atrio-ventricular aperture in man is guard...

The left atrio-ventricular aperture in man is guarded by

What are the tissues that form the skin in vertebrates, Q. What are the tis...

Q. What are the tissues that form the skin in vertebrates? The skin of vertebrates is made of epidermis is an external layer of epithelial tissue and dermis a layer of connecti

Zoonotic diseases-influenza, Influenza Influenza is an acute infectious di...

Influenza Influenza is an acute infectious disease caused by influenza viruses of genus Orthomyxovirus in family Orthomyxoviridae. The name Influenza is derived from an Italian ph

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