Eye lens, Biology

Assignment Help:

LENS - 

  1. In lumen of eye ball, a large colourless, transparent, more convex on back side, lens present covered by lens capsule.
  2. When white tissues are formed in it, it becomes less transparent. So catarect is caused.
  3. Refrective index of lens is 1.42. In lens yellow pigment present to check harmful sun rays.
  4. Lens is fixed in position.
  5. From cilliary body suspensory ligaments or zonulla of zinn are given out to keep lens in fixed position.
  6. On relaxing of suspensory ligaments, focal length of lens is reduced.
  7. Lens divides lumen into 2 unequal chambers.
  8. Anterior small aquous chamber & posterior large vitrous chamber.
  9. Aqueous chamber is filled by aquous humour (watery fluid).
  10. Vitrous chamber is filled by vitrous wharton's jelly humour (formed during development in embryo only once).
  11. Vitreous humour is dense contains 99% H O, remaining 1% vitrein protein, hyalorunic acid & collagen fibres.
  12. Vitrous humour maintains shape of eye ball by turger pressure. Around vitrous humour hyloid layer present.
  13. In retina a blind spot present where no rods & cones are present.
  14. In vitrous humour upto blind spot a hyloid canal is present.
  15. Intralocular pressure (pressure of aquous + vitrous humour) is about 20 - 25 mmHg. optical axis touches retina to a point or area i.e
  16. area centralis or yellow spot or macula lutea. Here xanthophill pigment is present.
  17. Its central part is fovea centralis.
  18. Here only cones are obliquely placed so enlarged image is formed.

Related Discussions:- Eye lens

Define the term - microfilaments and microtubules, Define the term - microf...

Define the term - microfilaments and microtubules The cytoskeleton is, in fact, termed as the "bone and muscle" of the eukaryotic cell, and is composed of a network, consisting

What is herbicide tolerant crops in evolutionary, Evolutionary ...

Evolutionary Herbicide tolerant crops (HTC) Increased use of herbicide can result in increase in development of weed resistance to that herbicide either through

How dna molecules are formed, As a result of DNA replication two DNA molecu...

As a result of DNA replication two DNA molecules come into existence. Why is it not correct to assert that two "new" DNA molecules are created? What is the name given to the proces

What do you understand by heterotrophic, What do you understand by Heterotr...

What do you understand by Heterotrophic? Organisms which are not capable of converting light into chemical energy. They should consume other organisms or material produced by o

Explain calvin cycle, Calvin cycle (the aka Calvin-Benson Cycle or the Car...

Calvin cycle (the aka Calvin-Benson Cycle or the Carbon Fixation) is the series of biochemical, enzyme-mediated reactions during which the atmospheric carbon dioxide is reduced an

What is plant tissues explain there types, What is Plant Tissues explain th...

What is Plant Tissues explain there types? Vascular plants have separate organs to carry out specialized functions. For instance, leaves function to convert radiant energy to

What is arsenite inhibitor, What is Arsenite  inhibitor Arsenite inhib...

What is Arsenite  inhibitor Arsenite inhibits synthesis of ATP,  in the conversion of 1,3-bisphosphoglycerate  to 3- phosphoglycerate, by  causing uncoupling of oxidation and

Define the carbohydrate utilization pattern test, Define the Carbohydrate U...

Define the Carbohydrate Utilization Pattern Test? Carbohydrates are composed of carbon, hydrogen and oxygen. These organic molecules are catabolized by large number of microorg

What are fossil fuels, Q. What are fossil fuels? The Fossil fuels like ...

Q. What are fossil fuels? The Fossil fuels like coal, oil and gas, form when organic material is preserved from the complete action of decomposers, generally buried deep and un

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