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 about the types of indicators, Define about the Types of indicators?...

Define about the Types of indicators? The various types of indicators used are: (i) Acid-base indicators (ii) Redox indicators (iii) Metal ion indicators (iv) Preci

Define central nervous system, Q. Define Central nervous system? The ne...

Q. Define Central nervous system? The nervous system begins as a simple tube during embryonic development (then anterior part expands and also ventricles are formed).  Foreb

Synapse, SYNAPSE - The point where 2 neurons combine is synapse. It ...

SYNAPSE - The point where 2 neurons combine is synapse. It is of 2 types - (i) Axosomic (between axon & cyton) (ii) Axodendric (between axon & dendron) Axon is term

What is biotic potential, Q. What is biotic potential? The Biotic poten...

Q. What is biotic potential? The Biotic potential is the capability of growth of a given population under hypothetical optimum conditions, i.e., in an environment without limit

Explain haccp, HACCP Normal 0 false false false ...

HACCP Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Can you explain radula, Q What is the radula? What is the function of this ...

Q What is the radula? What is the function of this organ? Some molluscs have a tongue-like structure with harsh saliences similar to small teeth. This structure is called as ra

Lab report, Why making a smoke print of a leaf

Why making a smoke print of a leaf

Omnispective classification, Omnispective Classification This is the ex...

Omnispective Classification This is the extension of the concept of natural classification put forward by Black Welder (1967). The approach seems quite realistic and pragmatic.

Leaves give off water vapour, Leaves give off water vapour Use two same...

Leaves give off water vapour Use two same pots of soil, one with a small plant and the other without. Cover the soil in every pot with cardboard as shown in the diagram after w

What is hemoglobin f, What is hemoglobin F? Why does the fetus need a diffe...

What is hemoglobin F? Why does the fetus need a different hemoglobin? Hemoglobin F is the hemoglobin found in the mammalian fetus and hemoglobin A is the normal hemoglobin. Hem

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