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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 ...
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 ...
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.
[3] [4] Optic cup morphogenesis is the invagination process occurring after neuroectoderm movement forms the spherical optic vesicle (Phase 1). Invagination is when a tissue folds back on itself. Over the course of approximately 12 hours, the distal end of the optic vesicle inner layer begins to flatten (Phase 2).
This process is known as neurulation. [8] When the tube is closed at both ends it is filled with embryonic cerebrospinal fluid. [9] As the embryo develops, the anterior part of the neural tube expands and forms three primary brain vesicles, which become the forebrain (prosencephalon), midbrain (mesencephalon), and hindbrain (rhombencephalon).
Plant embryonic development, also plant embryogenesis, is a process that occurs after the fertilization of an ovule to produce a fully developed plant embryo. This is a pertinent stage in the plant life cycle that is followed by dormancy and germination . [ 1 ]
A germination rate experiment. Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. [1]Plant physiologists study fundamental processes of plants, such as photosynthesis, respiration, plant nutrition, plant hormone functions, tropisms, nastic movements, photoperiodism, photomorphogenesis, circadian rhythms, environmental stress physiology, seed ...
Plant development is the process by which structures originate and mature as a plant grows. It is a subject studies in plant anatomy and plant physiology as well as plant morphology. The process of development in plants is fundamentally different from that seen in vertebrate animals. When an animal embryo begins to develop, it will very early ...