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

What is the notochord, What is the notochord? How is this structure formed?...

What is the notochord? How is this structure formed? The notochord is a rodlike structure that produces the supporting axis of the embryo and gives birth to the vertebral colum

Explain about the celiac disease, Explain about the Celiac Disease? Cel...

Explain about the Celiac Disease? Celiac disease (also called gluten enteropathy) is an intestinal disorder that results from an abnormal  immunological reaction to gluten. u p

What is a graduated cylinder and how is it used, What is a graduated cylind...

What is a graduated cylinder and how is it used? A graduated cylinder is a piece of laboratory glassware used to accurately calculate out volumes of chemicals for use in reacti

What are secondary roots, What are secondary roots? In origin how secondary...

What are secondary roots? In origin how secondary roots differentiate from shoots? Secondary roots are ramifications of the primary (major) root. The secondary roots emerge fro

Portal hypertension, Portal Hypertension: If you review the portal cir...

Portal Hypertension: If you review the portal circulation you may recall that normal blood flow to and from the liver depends on proper functioning of  the portal vein, the he

Botany, what is affinites of gymnosperm

what is affinites of gymnosperm

Explain femoral approach, Q. Explain Femoral Approach? This approach in...

Q. Explain Femoral Approach? This approach involves the insertion of a catheter over a guidewire i.e. inserted into a sheath in the right femoral artery. Systemic anticoagulati

What does balanced diet means, What does Balanced Diet means Balanced D...

What does Balanced Diet means Balanced Diet means diet which contains a variety of foods in such quantities and proportions that the need for energy, proteins, vitamins, minera

Gene targeting, Gene targeting: There is always a debate on gene integrat...

Gene targeting: There is always a debate on gene integration in to the host animal. It is random gene integration Vs gene targeting. Perhaps most significantly, pro-nuclear in

Reproduction in cnidarians, How does metagenesis in cnidarians differ from ...

How does metagenesis in cnidarians differ from the true alternation of generation shown by plants?

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