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

Animal Respiration, What type of respiration does earthworm has ? In many c...

What type of respiration does earthworm has ? In many complex animals, the cells of internal organs are distant from the outside environment; respiratory systems provide the passag

Dietary management of dyspepsia, Q. Dietary management of dyspepsia? Ke...

Q. Dietary management of dyspepsia? Keeping in mind the etiology, symptoms and complications of dyspepsia it must be clear that treatment and management of [his disorder does n

Define about the pancreatic cancer, Define about the Pancreatic Cancer? ...

Define about the Pancreatic Cancer? This is a condition often associated with abdominal pain, anorexia, nausea, and vomiting and weight loss. Ealing may aggravate pain. There m

Determine the chain in the dna molecule, Which type of chemical bond mainta...

Which type of chemical bond maintains the pairing of each chain in the DNA molecule? To produce the DNA molecule, purine bases bind to pyrimidine bases by intermolecular bonds

Types of synovial joint, TYPES OF SYNOVIAL JOINT - 1 .      BALL AND ...

TYPES OF SYNOVIAL JOINT - 1 .      BALL AND SOCKET JOINT - One bone forms a ball like head that fits into a socket formed in the other bone. Movement is possible in al

Basic structure of heart, Basic Structure of Heart The heart is small...

Basic Structure of Heart The heart is small organ about the size of one's fist, located in the middle and slightly to the left of the mediastinum in the chest. The wider t

Forms of ribosomes, FORM S OF RIBOSOMES (1 )      Bound form - Atta...

FORM S OF RIBOSOMES (1 )      Bound form - Attached to ER. Protein synthesis for secretion purpose occurs on bound ribosomes. (2 )      Free Ribosomes - Occur freely

Prevent and control staphylococcal food poisoning, To prevent and control S...

To prevent and control Staphylococcal food poisoning: • Avoid contamination of foods • Kill organism by heating, refrigeration • Personnel hygiene • Adequate cookin

Define the stability of your favourite protein kinase, You measure the stab...

You measure the stability of your favourite protein kinase and find that half of the protein is degraded every 10 minutes. How might you test whether the protein is degraded throug

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