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

Bjork-shiley valve (b-s)-types of valves, Bjork-Shiley Valve (B-S) : This...

Bjork-Shiley Valve (B-S) : This is one of the earliest types of tilting disc valves introduced in early 70's. The earlier models like concavo-convex disc valves were withdrawn fr

What are the symptom of short bowel syndrome, Q. What are the Symptom of sh...

Q. What are the Symptom of short bowel syndrome? Diarrhoea is the main symptom of short bowel syndrome. Other symptoms include: • Anorexia • Steatorrhoea • Heart bum a

Sunshine recorder, Sunshine recorder Sunshine recorder (Figure shown be...

Sunshine recorder Sunshine recorder (Figure shown below) measures the duration of sunshine. The recorder consists essentially of a glass sphere of about 10 cm in diameter mount

Define chromatography - basic separation technique, Define Chromatography -...

Define Chromatography - Basic Separation Technique? Chromatography is the most effective technique for the separation, purification and identification of one or more biological

How the visual images are projected, Since the visual images are projected ...

Since the visual images are projected in an inverted manner on the retina why don't we see things upside down? As the crystalline lens is a convex spherical lens it forms inver

Define briefly about the conjugated proteins, Define briefly about the Conj...

Define briefly about the Conjugated Proteins? Conjugated proteins are made up of simple proteins combined with a non- proteinous substance. The non-proteinous substance is know

Criteria of essentiality, Criteria of Essentiality Amon and Stout as e...

Criteria of Essentiality Amon and Stout as early as 1939, suggested certain criteria that an element must fulfil in order to be classified as essential. These criteria are lis

What is black mold, What is black mold? Mold is a fungus. Black mold is...

What is black mold? Mold is a fungus. Black mold is not an official term, since it is not possible to tell with the naked eye what type of mold is present, and many of them app

Lipid case study, Beginning with the entry of fatty acid into target cells,...

Beginning with the entry of fatty acid into target cells, describe in detail how inactivation of carnitine can lead to a high level of fatty acids in the blood.

Carbohydrate requirement during congestive cardiac failure, Q. Carbohydrate...

Q. Carbohydrate requirement during congestive cardiac failure? While the quantity of carbohydrate remains almost the same as per the RDI i. e, 60% of the total energy, the qual

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