Role of wound epidermis and apical epidermal cap, Biology

Assignment Help:

Role of Wound Epidermis and Apical Epidermal Cap

Earlier described that amputation, the stump epidermal cells at the wound edge migrate over and quickly cover the wound to from a multilayered apical epidermal cap. The formation of this cap depends upon the early innervations of the wound epidermis through nerve fibers. The cap fails to make if the limb is denervated before or immediately after amputation. If this cap is removed regeneration fails to take place. If an additional cap is grafted on the emergent blastema it induces regeneration of supernumerary limb. Thus the apical epidermal cap formed via wound epidermis is necessary for permitting regeneration. Any other epidermis grafted on the wound surface does not make the apical cap and does not support regeneration. This shows that only the apical cap that developed from the wound epithelium could promote and maintain regeneration of the limb.

In the non-regenerating amputated limb-stumps of older tadpoles and adults of frogs, the characteristic apical epidermal cap does not develop and thus regeneration does not take place. Experimental results point out that wound epidermis stimulates dedifferentiation and mitosis in the underlying cells arising from stump tissue so inducing the formation and growth of the blastema and the consequent regeneration of the limb. The blastema cells in the zone instantaneously adjacent to the apical cap remain in an undifferentiated and proliferating state, while those proximal to this zone start to differentiate. In this way proximal distal pattern of re-differentiation of blastema cells is controlled through the epidermal cap. You may recall that the apical ectodermal ridge (AER) of the embryonic limb bud also plays a identical role in allowing distal outgrowth of the limb. Both the AER in, embryonic limb development and apical cap of the regenerating limb stimulate cellular proliferation in cells situated beneath them and keep them from differentiating that enables differentiation of limb tissues in a proximo-distal sequence.


Related Discussions:- Role of wound epidermis and apical epidermal cap

Insulin and its functions, People with Type 1 DM produce no insulin. People...

People with Type 1 DM produce no insulin. People with Type 2 DM do not always produce enough insulin. Insulin is used medically to treat some forms of diabetes mellitus. Patients w

Explain the ecosystems, Explain the Ecosystems? The ecosystem is yet an...

Explain the Ecosystems? The ecosystem is yet another level, or ecological unit, studied by ecologists. An ecosystem encompasses all of the organisms (all the populations-the en

Define the food system in space, Define the Food System in space? Mercu...

Define the Food System in space? Mercury (1961-1963) astronauts had to eat bite-sized cubes, freeze dried powders, and semi liquids stuffed in aluminium tubes. For most asbonau

Introduction to ecology, Ecology is a interdisciplinary branch of science t...

Ecology is a interdisciplinary branch of science that deals with inter relationship between living organism and their environment. The term ecology (from greek, oikos-meaning ho

Describe about the extra-ocular muscles, Describe about the extra-ocular mu...

Describe about the extra-ocular muscles The eye is comprised of extra-ocular and intra-ocular muscles. The extra-ocular muscles are comprised of 4 recti and 2 obliques. The rec

Why iodine is vital for human beings, Q. Why iodine is vital for human bein...

Q. Why iodine is vital for human beings? Iodine is a essential chemical element for the proper functioning of the thyroid since it is part of the hormones produced by this glan

Mirco, what is wrong with pasteurs conclusion

what is wrong with pasteurs conclusion

How to draw the cell in metaphase, Start with a cell with chromosome number...

Start with a cell with chromosome number 2n=6, and having two acrocentric pairs and one metacentric pair of chromosomes. Draw the cell in metaphase I. Indicate one pair of sister c

Define denaturation, Denaturation: With respect to the nucleic acids, refe...

Denaturation: With respect to the nucleic acids, refers to the conversion from the double-stranded to single-stranded state, many times achieved by heating or alkaline conditions.

Pomology, Pomology :  This is the study of fruits and fruit yielding plants...

Pomology :  This is the study of fruits and fruit yielding plants of commercial importance.  Pomology is a branch of botany which studies or cultivates pome fruit, and particularly

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