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

The atomic number of the isotope 238u of uranium is 92, The atomic number o...

The atomic number of the isotope 238U of uranium is 92. The nucleus of this isotope contains a) 184 protons, 92 electrons, and 54 neutrons. b) 92 protons and 146 neutrons. c) 92 pr

How aggregation occur in sickle-cell anemia, How does aggregation occur in ...

How does aggregation occur in sickle-cell anemia? Place the steps in the correct order from no aggregation to sickle red blood cell. Note that deoxyhemoglobin is generally in the T

Define drug effects on food intake - cause dry mouth, Define drug effects o...

Define drug effects on food intake - cause dry mouth? cause dry mouth (xerostomia) : Lack of saliva makes it difficult to masticate and swallow foods, especially those of a dry

Explain what is correction of hypovolemia, Explain what is Correction of Hy...

Explain what is Correction of Hypovolemia ? Intravenous fluids should be given to correct hypovolemia and optimize preload to the heart. This is particularly important in sept

What is uric acid , Uric acid is the main nitrogenous waste product o...

Uric acid is the main nitrogenous waste product of uricotelic organisms (birds, insects and reptiles), but is also established in ureotelic organisms from the breakdown of the puri

Characteristic features of phylum arthropoda, Characteristic Features of Ph...

Characteristic Features of Phylum Arthropoda Well-developed muscular system along with striated muscles attached to the exoskeleton, and visceral organs having smoot

What is chylomicrons , Chylomicrons, the widest of the lipoproteins, are...

Chylomicrons, the widest of the lipoproteins, are synthesized in the intestine. They including ingested triacylglycerols to other tissues, mainly skeletal muscle and adipose tissue

Which is the type of nitrogen waste, Which is the type of nitrogen waste el...

Which is the type of nitrogen waste eliminated by beings of the class Reptilia? These beings excrete mainly uric acid. This substance is less toxic than ammonia and it can be k

What is soil fertility evaluation, Soil fertility evaluation  In order ...

Soil fertility evaluation  In order to maintain soil fertility, nutrients removed from the soil by crops must be restored by the application of manures and fertilizers.  The se

Define genetic susceptibility factors for obesity, Define Genetic Susceptib...

Define Genetic Susceptibility Factors for Obesity? Some people inherit a tendency to become fat. Earlier, it was thought that genetic inheritance ranged from 66% to 80% but now

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