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

Explain national nutritional anaemia prophylaxis programme, Explain Nationa...

Explain National Nutritional Anaemia Prophylaxis Programme (NNAPP)? In past, both access to and intake of iron-folate tablets have been poor in children and therefore had a lit

Explain about lymphatic system, Why in inflammatory and infectious conditio...

Why in inflammatory and infectious conditions may clinical signs related to the lymphatic system occur? The lymph nodes, or lymph glands, have lymphoid tissue that makes lympho

Comparative picture of ecosystem, Q. Comparative picture of ecosystem? ...

Q. Comparative picture of ecosystem? An ecosystem having higher diversity means the number of species and interactions between them which constitute the food web, is large. In

Explain about natural pigments, Explain about natural pigments There ha...

Explain about natural pigments There has been an extensive search of the microbial, plant and animal kingdoms for pigments that possess both high tinctorial power/strength (a m

Parasitology, what is giardia lamblia and deasis

what is giardia lamblia and deasis

Can you explain diabetes mellitus, Q. What is diabetes mellitus? Diabet...

Q. What is diabetes mellitus? Diabetes mellitus is the disease caused by action or deficient production of insulin and the consequent high blood glucose level and low glucose u

Fundamental polymers of life, The synthesis of the three fundamental polyme...

The synthesis of the three fundamental polymers of life, DNA, RNA and protein, is template-directed. This means that - Answer A. the monomers are assembled one by one in a sequence

Explain what is probing depth, Q. Explain What is Probing Depth? This p...

Q. Explain What is Probing Depth? This parameter is applicable to one stage implants when they are evaluated prior to prosthetic phase and used to evaluate the health of the im

Avian (fowl cholera), Avian (fowl cholera) Fowl cholera is a contagious...

Avian (fowl cholera) Fowl cholera is a contagious septicaemic disease of almost all classes of fowl. The causal agent is Pasteurella multocida.Serotypes A:1 and A:3 are usually

Biotechnology in conservation of animal biodiversity, Cryopreseravtion of g...

Cryopreseravtion of gametes , embryos or DNA segments can be quite an effective and safe approach for breeds or strains whose populations are too small to be conserved by any other

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