Search results
Results from the WOW.Com Content Network
These diverticula make their appearance before the closure of the anterior end of the neural tube; [1] [2] after the closure of the tube around the 4th week of development, they are known as the optic vesicles. Previous studies of optic vesicles suggest that the surrounding extraocular tissues – the surface ectoderm and extraocular mesenchyme ...
First, there is an outpocketing of the neural tube called optic vesicles. Development of the optic vesicles starts in the 3-week embryo, from a progressively deepening groove in the neural plate called the optic sulcus. Some studies suggest this mechanism is regulated by RX/RAX transcription factor. [8]
The optic vesicles project toward the sides of the head, and the peripheral part of each expands to form a hollow bulb, while the proximal part remains narrow and constitutes the optic stalk. [1] [2] Closure of the choroidal fissure in the optic stalk occurs during the seventh week of development. The former optic stalk is then called the optic ...
The optical vesicle (which will eventually become the optic nerve, retina and iris) forms at the basal plate of the prosencephalon. The spinal cord forms from the lower part of the neural tube. The wall of the neural tube consists of neuroepithelial cells, which differentiate into neuroblasts, forming the mantle layer (the gray matter).
The neural fold is a structure that arises during neurulation in the embryonic development of both birds and mammals among other organisms. [1] [2] This structure is associated with primary neurulation, meaning that it forms by the coming together of tissue layers, rather than a clustering, and subsequent hollowing out, of individual cells (known as secondary neurulation).
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
The coalescence of the neural folds occurs first in the region of the hind-brain, and from there extends forward and backward; toward the end of the third week the front opening (anterior neuropore) of the tube finally closes at the anterior end of the future brain, and forms a recess which is in contact, for a time, with the overlying ectoderm ...
During embryonic development of the eye, the outer wall of the bulb of the optic vesicles becomes thickened and invaginated, and the bulb is thus converted into a cup, the optic cup (or ophthalmic cup), consisting of two strata of cells.