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

Determine the steps for withdrawing the insulin, Determine the Steps for Wi...

Determine the Steps for Withdrawing the Insulin The important thing about measuring a dose is to use the front of the plunger not the back - Check doctor's prescription.

Endocrine glands - gastro-intestinal mucosa, GASTRO-INTESTINA L MUCOSA - ...

GASTRO-INTESTINA L MUCOSA - It develops from the endoderm of the embryo. Inner most layer of the wall of the alimentary canal is called mucosa. Certain cells of the mucosa

Factors responsible for food spoilage, Q. Can you explain Factors responsib...

Q. Can you explain Factors responsible for food spoilage? Spoilage, as you would realize, is quite a natural phenomenon. All foods undergo varying degrees of deterioration or s

Dna double helix , In the year of 1953, Watson and Crick worked out the...

In the year of 1953, Watson and Crick worked out the 3-D structure of DNA, beginning from X-ray diffraction photographs   taken through Wilkins and Franklin. They decreased which D

Complications causes by gastro oesophageal reflux disease, Q. Complications...

Q. Complications Causes by gastro oesophageal reflux disease? Apart from the symptoms, which you have just read above, there are a few extra oesophageal manifestations of GERD.

Degradation of fats, Q. Explain Degradation of Fats? Fats are the este...

Q. Explain Degradation of Fats? Fats are the esters of glycerol and fatty acids and are called as 'glycerides'. Fats are susceptable to hydrolysis, oxidation and other che

State the term- hue, State the term- Hue Hue  is the dominant spectral ...

State the term- Hue Hue  is the dominant spectral colour (rainbow) and is related to the wavelength of light. In Munsell system there are five principal hues; red (R), yellow (

Importance of human milk for infant growth and development, Define the Impo...

Define the Importance of Human Milk for Infant Growth and Development? Let us now look at the value of human milk in promoting infant growth and development.  Success of lactat

Define neural and neurotransmitter control, Q. Define Neural and Neurotrans...

Q. Define Neural and Neurotransmitter Control? Coronary arteries are richly innervated by adrenergic and parasympathetic nerves. Both alpha 1 and alpha 2 adrenergic receptors a

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