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

Symptoms and complications of atherosclerosis, Q. Symptoms and Complication...

Q. Symptoms and Complications of atherosclerosis? Symptoms Excessive weight, hypertension, high levels of cholesterol and triglycerides. Complications Myocardia

How fever, How Fever,Illness,Infections,Injury affects the BMR? Any ill...

How Fever,Illness,Infections,Injury affects the BMR? Any illness or fever caused by an illness influences the metabolic rate. Fevers increase the metabolic rate by about 7% for

What is the microflake - t dehydration, What is the Microflake - T Dehydrat...

What is the Microflake - T Dehydration? This technique involves the drying of a continuous sheet of foam 20 mm thick on a continuous stainless steel belt. The later is heated f

How can the abundance and diversity of living beings, How can the abundance...

How can the abundance and diversity of living beings in the tropical forests be explained? The biodiversity of these ecosystems can be defined by the great availability of the

Blastulation, Blastulation  Formation of blastula from morula is called...

Blastulation  Formation of blastula from morula is called as blastulation. During early cleavage the blastomere maintain spherical shape and mulberry like, this stage of emb

Mixed tricuspid stenosis and regurgitation , Mixed Tricuspid Stenosis and R...

Mixed Tricuspid Stenosis and Regurgitation:  Rheumatic involvement of the tricuspid valve is often seen in association with involvement of mitral and rarely aortic valve. Isolated

Explain about the weight imbalance, Explain about the Weight Imbalance? ...

Explain about the Weight Imbalance? You are aware that obesity is one of the major public health problems of the world, Earlier a problem of the developed nations; it is now in

Difference between medullated and non-medullated fibres, DIFFERENCE S BETW...

DIFFERENCE S BETWEEN MEDULLATED AND NON-MEDULLATED NERVE FIBRES       1. Medullated (Myelinated) Nerve Fibres Medullary sheath is present.

What would the result of a haploid egg, If a diploid sperm fertilized a hap...

If a diploid sperm fertilized a haploid egg, what would the result be? a.Haploid (n) b.Diploid (2n) c.A mixture of diploid (2n) and haploid (n) d.Triploid (3n)

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