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

Sericulture, i want to know about sericulture for assignment degree level

i want to know about sericulture for assignment degree level

Composting, C o m p o s t i n g It is a modification of a conv...

C o m p o s t i n g It is a modification of a conventional or solid manure handling system with anaerobic decomposition. Types of composting systems include windrow, b

Surveys - accidents in industries, Surveys - Accidents in Industries T...

Surveys - Accidents in Industries The surveys done in industries have pointed out that leading cause of accidents is the overexertion or workers working beyond their physical

Define dietary and non dietary factors - causation of cancer, Define Dietar...

Define Dietary and Non Dietary Factors - Causation of Cancer? Several dietary and non-dietary factors (including genetics) can increase the risk in the causation of cancer. Som

Cytokinesis, Simultaneously with the formation of two daughter nuclei, a cl...

Simultaneously with the formation of two daughter nuclei, a cleavage furrow appears in the middle of the cell. The furrows gradually deepen and divide the cell into two daughter ce

Define classification of carbohydrates - polysaccharides, Define classifica...

Define classification of carbohydrates - Polysaccharides? This classification is based on the number of monosaccharide units they contain, Polysaccharides are those polymers of

Ablation experiment, Ablation experiment  is an experiment designed to prod...

Ablation experiment  is an experiment designed to produce an animal deficient in one or the few cell types, in order to study cell lineage or the cell function. The logic is to mak

Explain the term- pedon and polypedon, Explain the term- pedon and polypedo...

Explain the term- pedon and polypedon The characteristics of soil do not change vertically downwards only, there are lateral variations also as soil is a three dimensional body.

Explain various types of activities of a cell, The main arena of various ty...

The main arena of various types of activities of a cell is: 1. Plasma membrane 2. Mitochondrian 3. cytoplasm 4. Nucleus Cytoplasm

Explain about the antioxidant activity of sugar, Explain about the Antioxid...

Explain about the Antioxidant Activity of Sugar? Several carbohydrates are tremendous scavengers for metal ions. Glucose, fructose and sugar alcohols (sorbitol and mannitol) ha

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