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

Define intravascular fluid compartment - extracellular fluid, Explain intra...

Explain intravascular fluid compartment - extracellular fluid? The extracellular fluid compartment is sub-divided into the intravascular fluid compartment (fluid within the blo

Diversty of living organisms, write down the division of cryptogamae and p...

write down the division of cryptogamae and phanerogamae

Explain third degree atrioventricular block, Q. Explain Third Degree Atriov...

Q. Explain Third Degree Atrioventricular Block? In older patients with known or suspected CAD, third degree heart block at rest should be a relative contraindication to stress

Give an introduction to intensive care, Give an introduction to intensive c...

Give an introduction to intensive care ? Intensive Care Medicine has its origins from the polio epidemic of 1952 in Copenhagen. Patients who suffered respiratory paralysis were

What is the conjugate acid, Calculate the pH: 300mL of 0.25M sodium ascorba...

Calculate the pH: 300mL of 0.25M sodium ascorbate plus 150mL of 0.2M HCl (the pKa of ascorbic acid is 4.04) okay, what's the conjugate acid and base of this problem? Can someone wa

The kidney.., where is the inlet and outlet of the diaylsis machine

where is the inlet and outlet of the diaylsis machine

What is patient''s plasma osmolarity after the infusion, Tina administered ...

Tina administered 1 liter of sterile distilled water IV to a patient. Predict the direction (increase, decrease, no change) you would expect Tina's infusion to have produced in the

Agro industrial-by-products from sugar industry, By-Products from Sugar Ind...

By-Products from Sugar Industry India is one of the important sugarcane (Saccharum officinarum) growing countries of the world. Five main by-products are available from the su

Why is it important to be familiar with the laboratory, Why is it important...

Why is it important to be familiar with the laboratory apparatus and their uses? If you do not use instruments or lab apparatuses correctly (or use an apparatus for something i

Types of hormones, T ypes of hormones - (i) Releasing and Inhibitory ...

T ypes of hormones - (i) Releasing and Inhibitory hormones - Hormones of hypothalamus and kidney (renin) which control secretion of trophic hormones. (ii) Trophic hormon

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