Neurulation in amphibians, Biology

Assignment Help:

Neurulation in Amphibians

The first step in the neurulation process is the flattening and thickening of dorsal ectoderm to form neural plate. The plate of cells are different from the rest of ectoderm cells in that they have changed shape and appear more columnar. The edges of the neural plate after that rise above along the rest of the neural plate to form neural folds. The neural folds are now found together the two flanks of a central depression called neural groove. The neural groove extends along the entire middorsal line of the embryo. Eventually the neural folds meet in the middle above the deepening neural groove and fuse to make the neural tube. At the time of rolling of neural plate to make the neural tube, the neuroepithelial cells at the lateral folds of the neural plate develop constrictions at their apical edges.

This alterations the shape of columnar epithelial cells into pyramidal cones. As the surface area of apical end of neural epithelial cells turns into smaller relative to the basal surface, the rolling up of the neural plate and formation of neural tube occurs. Along with the fusion of neural folds along the middorsal line, the neural ectoderm separates from epidermal ectoderm that now covers the neural tube and completely surrounds the embryo. The change in the shape of cells in the neural tube results in the regionalisation of neural tube. In the cephalic end, i.e. the end which will differentiate into brain, the wall of the tube is broad and thick and a series of swellings and constrictions develop which define the several divisions of brain. Caudally, towards the posterior end, the tube is simple and narrow extending into the tail.


Related Discussions:- Neurulation in amphibians

Pdf, study of phenomena of apical dominance

study of phenomena of apical dominance

What ways farmers try to improve the quality of their soil, a) In what way...

a) In what ways do farmers try to improve the quality of (i) their soil, (ii) their crop plants?    b) What other steps do farmers take to maximise the yield from their

Widal test is used for the diagnosis, Widal test is used for the diagnosis ...

Widal test is used for the diagnosis of: 1. Malaria 2. Pneumonia 3. Tuberculosis 4. Typhoid Typhoid

Ciliary and flagellar movements, Normal 0 false false false...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Joints, JOINTS - The structural arrangement of tissues which connect 2 ...

JOINTS - The structural arrangement of tissues which connect 2 or more bones together at their place of meeting is called a joint. Study of joint is arthrology. Joint make the

Determine the term - neuropsychological approach, Determine the term - Neur...

Determine the term - Neuropsychological approach The neuropsychological approach relies on the use of tests in which poor performance may indicate either focal (localised) or d

Gene constructs - transgenic animals, G e n e constructs Designing a...

G e n e constructs Designing and cloning of the gene construct is the fundamental step in the generation of transgenic animals, essentially determining success or failure of

Explain about the lipoproteins, Explain about the Lipoproteins? These a...

Explain about the Lipoproteins? These are the Multicomponent complexes of lipids and proteins that form distinct molecular aggregates. They contain polar and neutral lipids, ch

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