Lec.8 NEURULATION

Question 1

____ leads to the formation of the neural tube, the precursor of the central nervous system (brain and spinal cord).

This organ system is the first to initiate its development however, it is overtaken by the ____, which is the first organ system to gain function.

Answer 1

Neurulation

vascular system

Question 2

*Neural tube
During neurulation the epiblast is induced to form ____

A dorsal thickening in the anterior ectoderm accompanied with regression of the primitive streak is seen.

This elliptical region of specialized thickened ectoderm is referred to as the ____

Answer 2

neural ectoderm

neural plate

Question 3

The neural plate will go into a subsequent lengthening and narrowing.

Two lateral elevations, the neural folds, will develop on either side of a depressed mid-region known as the ____

The neural folds continue to elevate and eventually fuse to create the ____

Answer 3

neural groove

neural tube

Question 4

*Neural tube
This primary neurulation creates the brain and most of the spinal cord.

In the tail bud, the neural tube is formed by ____
This is a different mechanism, without neural folding, in which the spinal cord initially forms as a solid mass of epithelial cells, and a central lumen develops secondarily by ____

Answer 4

secondary neurulation

cavitation

Question 5

*Neural tube
During neurulation, the ____ is entirely proliferative; cells do not exit the cell cycle and start neuronal differentiation until after the neural tube closure.

Cell proliferation is also accompanied by some degree of apoptosis.
It breaks the continuity between the neuroepithelium and surface ectoderm.

Answer 5

neuroepithelium

Question 6

*Neural crest
As the neural folds elevate, cells of the lateral border migrate into the ____

Induction of neural crest cells requires interactions between neural and overlying surface ectoderm.

Neural crest cells are specified as the result of an inductive instruction by the surface ectoderm.

Answer 6

mesoderm

Question 7

*Neural crest
Neural crest cells that leave the anterior parts of the neural folds, before closure of the neural tube, contribute to the ____

They can also differentiate into ____ of the cranial ganglia, Schwann cells and melanocytes.

Answer 7

craniofacial skeleton

neurons

Question 8

The ____ is regarded as a pluripotent stem cell population that makes vital contributions to a wide array of both neural and non neural organ systems.

This ends the discussion on neurulation initial formation of the Central Nervous System.

Answer 8

neural crest