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

How does hcl also directly participate in digestion, Besides being fundamen...

Besides being fundamental for the activation of the main gastric digestive enzyme how does HCl also directly participate in digestion? With its corrosive effect, HCl also helps

The mirrows reach or grayling zone, The mirrows reach or grayling zone ...

The mirrows reach or grayling zone This zone has a less steep gradient, than the trout beck. The river here still flows swiftly, though the current is not fast and conditions

Illustrate the applications of vitamin B6, Illustrate the Applications of v...

Illustrate the Applications of vitamin B 6 The heating processes employed in the industry for the sterilization of milk based formulations will greatly reduce their vitamin B

Assessment of tricuspid and pulmonary orifice areas, Assessment of Tricusp...

Assessment of Tricuspid and Pulmonary Orifice Areas Due to the rarity of tricuspid stenosis and pulmonary stenosis, no general agreement exists on what constitutes critical o

Under which form is nitrogen fixed by living beings, Under which form is ni...

Under which form is nitrogen fixed by living beings? Most living beings cannot use molecular nitrogen to get nitrogen atoms. Producers fix nitrogen mostly from nitrate (NO3-).

Explain procedure for isolation of pure culture, Explain Procedure for Isol...

Explain Procedure for Isolation of Pure Culture? Now carry out the exercise following the steps enumerated herewith. 1. Label the name of the organism on the bottom of the p

Define about ecological models, Why do ecological models commonly have limi...

Why do ecological models commonly have limited applications? The applications of ecological models are limited due to the models are normally very simple and do not accurately

Accident proneness, Accident Proneness The close observation of accid...

Accident Proneness The close observation of accident causation theory brings out this fact that most accidents can be traced to error on the part of a number of individual em

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