Our work demonstrates that early developing neural retinas can be divided into two layers, the outer and inner neuroblast layers. Analysis of expression of transcription factors in early human retina "Here, we analyze the expression of transcription factors that are involved in the early development of the retina in human embryos at 6-12 weeks post-conception.Historic Embryology: 1906 Eye Embryology | 1907 Development Atlas | 1912 Eye Development | 1912 Nasolacrimal Duct | 1917 Extraocular Muscle | 1918 Grays Anatomy | 1921 Eye Development | 1922 Optic Primordia | 1925 Eyeball and optic nerve | 1925 Iris | 1927 Oculomotor | 1928 Human Retina | 1928 Retina | 1928 Hyaloid Canal | Historic Disclaimer Vision Links: vision | lens | retina | placode | extraocular muscle | cornea | eyelid | lacrima gland | vision abnormalities | Student project 1 | Student project 2 | Category:Vision | sensory Retinoblastoma is retinal cancer that allowed researchers to identify retinoblastoma protein (Rb), the first identified tumour suppressor protein acting as a G1 cell cycle checkpoint. Retinitis pigments is a degenerative retinal disease. The retina is also a key focus of clinical research, as genetic or environmental damage and vision loss is generally a result of damage to the retinal cells or their processes. It has a complex differentiation involving both a neural retina and a pigmented retina, in the embryo separated by a space and in the adult closely apposed to each other. The retina and its development has been the subject of research from the early histology studies of Santiago Ramón y Cajal (1852 - 1934) and Camillo Golgi (1843 - 1926). 6.1 Virtual Slide - Regions of Interest.They ensure central form vision and colour perception. The number of the cones amounts to 7 million in the human retina. The cones are active only in bright illumination conditions. at night, and have high sensitivity to light. They ensure eyesight in poor illumination, e.g. The total number of rods in the retina is about 130 million. The rods represent regular cylindrical formations from 40 to 50 microns long. These types of cells are considered to be the first neuron of the retina. The cone-shaped and rod-shaped cells, or simply the rods and cones, were called so because of the shape of the outer segment. The second layer – light-sensitive cells (photoreceptors) These cells are a part of a so-called hematoretinal barrier which ensures selective input of substances from the blood capillaries of the choroid into the retina. The pigment epithelium cells have the shape of a hexahedral prism and are simply arranged in a line. The pigment epithelium is composed of a single layer of densely packed cells containing a big amount of pigment. The pigment epithelium extends over the whole optic section of the retina and borders directly on the underlying choroid, being connected to the vitreous plate. These are followed by external limiting membrane, outer nuclear layer, outer plexiform (synaptic) layer, inner nuclear layer, inner plaxiform layer, ganglion cell layer, nerve fiber layer, inner limiting membrane. The main layers are pigment epithelium and light-sensitive cells (photoreceptor layer). The microscope discerns 10 layers in the retina – counted from inside -out. Macula disorder may considerably reduce the vision. The macula ensures central vision since it contains numerous photo receptors – namely the cones. The macula (macular zone, yellow spot) is the most important part of the retina. The retina has varying thickness in different sections: 0.4 – 0.5 mm at the edge of the optic nerve head 0.2 – 0.25 mm at the central fovea only 0.07 – 0.08 mm at the foveal pit about 0.1 mm at the ora serrata. The retina is most closely linked with the underlying layers of the eyeball along the edge of the optic nerve head. The retina creates an image projected on its surface with help of the cornea and crystalline lens, and transforms it into nerve impulses sent to the brain. The retina is a light-sensitive layer of nerve tissue lining the inner surface of the eye.
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