Explain the barrier function in the cornea, Biology

Assignment Help:

Explain the barrier function in the cornea.

Barrier Function:

It is the first line of barrier between the external environment and the corneal stroma. The superficial epithelial cells are encircled by tight junctions (zonula occludens).

These superficial epithelial cells serve as semi-pernieable high resistance (12- 16kQ) membrane. It prevents niovement of fluid from tear to stroma. It is useful for maintenance of epithelial barrier. The maintenance is done by mitosis of basal cells and migration of new basal cells from the limbal stern cells. So the corneal epithelium is maintained by a balance among the process of centripetal cell migration (120pm/wk), mitosis, and shedding of superficial cells. The XYZ hypothesis of corneal epithelial maintenance by Thoft and Friend is X+Y=Z. The limbal epithelium has the highest mitotic rate followed by peripheral cells and central cells have the lowest mitotic mte.


Related Discussions:- Explain the barrier function in the cornea

Deficiency diseases-ketosis, Ketosis Ketosis, also known as acetonaemia...

Ketosis Ketosis, also known as acetonaemia or ketonaemia is a multifactorial disorder that commonly occurs in dairy cows and buffaloes immediately after calving or in early lac

Evolution/genetics, Why do biologists believe humans, chimpanzees, and gori...

Why do biologists believe humans, chimpanzees, and gorillas all came from an ancient ancestor

Excretory system - ureters, URETERS From hilum of each kidney emerge...

URETERS From hilum of each kidney emerges out a tube. Wall is thick. Lumen is star shaped. 28 cm. long. Transitional epithelium present in wall. Open in to urinary bla

Adaptation and learning function of consciousness, Q. Adaptation and learni...

Q. Adaptation and learning function of Consciousness? Adaptation and learning function: Adaptation to novel experiences requires more conscious involvement, for successful lear

Explain the soft diet, Explain the soft diet The soft diet provides so...

Explain the soft diet The soft diet provides soft whole food that is lightly seasoned and moderately low in fibre. The foods have a soft  texture and are easy  to digest. Smal

Explain acute mr murmur in heart dieases, Explain Acute MR Murmur in heart ...

Explain Acute MR Murmur in heart dieases? MR due to ruptured papillary muscle, ruptured chordae tendinae, or due to Infective Endocarditis/Myocardial infarction. Characteri

In hormonal terms why does menses occur, In hormonal terms why does menses ...

In hormonal terms why does menses occur? Menses is the endometrial monthly desquamation that happens as the estrogen and progesterone levels fall after the regression of the co

Define vacuum production and thermal processing - canning, Define Vacuum pr...

Define Vacuum production and Thermal processing - Canning? Vacuum production - This can be obtained by filling the heated product into the can, by heating the can and content

How does the embryo turn from gastrula into neurula, Q. How does the embryo...

Q. How does the embryo turn from gastrula into neurula? How is the neural tube formed? What is the embryonic origin of the nervous system in vertebrates? The neurula stage is c

What is population density, Q. What is population density? The Populati...

Q. What is population density? The Population density is the relation between the number of individuals of a population and the area or volume they occupy. For instance, in 200

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