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

Do you know what the recommendations for fibre are, Do you know what the re...

Do you know what the recommendations for fibre are? Well, the crude fibre intake should be 14 g/1000 Kcal. For adult woman 25 g/day and for adult man 38 g/day is desirable.

What are the types of proteins in metabolism of lens, What are the types of...

What are the types of proteins in metabolism of lens? Soluble Proteins Its synthesis takes place in the equatorial part on the surface of lens. a. Alpha crystallins

Describe the recovery process of an extracellular product, Question 1: ...

Question 1: Describe the recovery process of an extracellular product through downstream processing. Different criteria's for the choice of recovery process Brief on

Genetically modified foods-golden rice, Normal 0 false false ...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Production diseases, Pr o d u c t i o n Diseases The production...

Pr o d u c t i o n Diseases The production diseases, which were previously referred as metabolic diseases, include diseases like parturient paresis (milk fever), downer

Vitamin, fish liver oil is rich in which vitamin ???

fish liver oil is rich in which vitamin ???

Male reproductive disorders-cryptorchidism, Cryptorchidism Cryptorchid...

Cryptorchidism Cryptorchidism or incomplete descent of testis or retention of testis in the abdominal cavity occurs in all domestic species but is seen most commonly in stalli

State the definition of respiration, State the Definition of respiration ...

State the Definition of respiration Respiration is an act of breathing. (i.e. rise and fall of the chest).  Respiration hastwo parts i.e. inhalation and exhalation. When we bre

How are antivenoms produced, Q. How are antivenoms produced? Why are antive...

Q. How are antivenoms produced? Why are antivenoms an example of passive immunization? Antivenoms are obtained by the following process: the venom (antigen) is inoculated into

Imaginal discs, Imaginal Discs In the holometabolous larva, there are ...

Imaginal Discs In the holometabolous larva, there are two cell populations: (1) The larval cells that are used for the larval structures and (2) The imaginal disc and th

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