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

Zearalenone, Zearalenone It was first isolated as the agent responsibl...

Zearalenone It was first isolated as the agent responsible for vulvovaginitis in pigs has very little acute toxicity, but there should be some concern about chronic exposure t

Polarity do water-soluble and fat-soluble substances, Q. Which type of pola...

Q. Which type of polarity do water-soluble and fat-soluble substances respectively have? Water-soluble substances are polar molecules that are they have electrically charged ar

Briefly describe about caramelization, Briefly describe about Caramelizatio...

Briefly describe about Caramelization? Caramelization results from the action of heat on sugars at about 175º C. At high temperatures, sugars dehydrate, break down and polymeri

Terminal process of diseased stage, Terminal process of diseased stage ...

Terminal process of diseased stage This is the last stage in the process of disease. In this stage, the disease process is halted either temporarily or permanently. There are t

Determine the nucleus transplantation technology, Why are the recombinant D...

Why are the recombinant DNA technology and the nucleus transplantation technology still dangerous? The recombinant DNA technology and the nucleus transplantation technology (cl

Kingdom, general characteristics of sponges

general characteristics of sponges

What is the function of the citric acid cycle, What is the function of the ...

What is the function of the citric acid cycle? The hnction ofthe  citric acid cycle can be discussed as  follows. The  intermediates of citric acid cycle are used as  precursor

Flying fish pisces, the characteristics of flying fish belong to pisces

the characteristics of flying fish belong to pisces

Major metabolic gases transported by the blood, Q. Which are the two major ...

Q. Which are the two major metabolic gases transported by the blood? The major metabolic gases transported by the blood are molecular carbon dioxide (CO 2 ) and oxygen (O 2 ).

Invertebrates, #question.3 different genera of invertebrates

#question.3 different genera of invertebrates

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