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They are not very spread at all they are contained mainly within the Fovea, a region at hte posterior of the eye.
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How many rod cells and cone cells in human body?
Rods approximately 125 millions and are spread all over the peripheral retinaCones approximately 6 millions
What is the retina made up of?
the innermost light-sensitive membrane covering the back wall of the eyeball; it is continuous with the optic nerve6 layers of cells that line the back of the eyeball.One layer is sensitive to light and is the first step in turning light into vision.These cells are a part of your brain.The retina is the layer of cells in the back of the eyes responsible for detecting light, which in turn allows you to see. The specific cells responsible for detecting light are the photoreceptors, more commonly referred to as rods and cones.
What is different about the region of the retina called the fovea compared with the rest of the retina?
The fovea or fovea centralis that is a pit in the central region of the macula of the retina with a high concentration of cone photoreceptors (red, blue and green) that allows for 100% visual acuity including color vision comprises less than 1% of retinal size but takes up over 50% of the primary visual cortex in the brain.
What is the job of the retina?
The retina receives the image seen through your eye, only in reverse up to down. It transmits this image through the optical nerve and your brain returns the inverted image to its correct right side up. The retina does basic optical processing, such as edge detection/enhancement and colour separation.The retinal image is considerably distorted - it's formed over the inside of an imperfect sphere. The brain does major processing to correct geometric errors. It also preserves "uprightness" - if you tilt your head, you *should* see the world tilt as well.The retina has a highly-sensitive fovea, responsible for fine vision, with the majority of the retina giving coarse detail.The retina in a human eye turns the light or whatever it is that we see into something we an understand and it passes it on to our optic nerve, which sends it to our brain for us to react.The vertebrate retina is a light sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical events that ultimately trigger nerve impulses. These are sent to various visual centers of the brain through the fibers of the optic nerve. In vertebrate embryonic development, the retina and the optic nerve originate as outgrowths of the developing brain, so the retina is considered part of the central nervous system (CNS).[1]. It is the only part of the CNS that can be imaged directly. The retina is a complex, layered structure with several layers of neurons interconnected by synapses. The only neurons that are directly sensitive to light are the photoreceptor cells. These are mainly of two types: the rods and cones. Rods function mainly in dim light, while cones support daytime vision. A third, much rarer type of photoreceptor, the photosensitive ganglion cell, is important for reflexive responses to bright daylight. Neural signals from the rods and cones undergo complex processing by other neurons of the retina. The output takes the form of action potentials in retinal ganglion cells whose axons form the optic nerve. Several important features of visual perception can be traced to the retinal encoding and processing of light. ---- Found on www.wikipedia.orgThe retina converts light into electrical signals which are sent to the brain via the optic nerve.make you able to hold for breath for longer than 7 secondsThe retina receives the image seen through your eye, only in reverse up to down. It transmits this image through the optical nerve and your brain returns the inverted image to its correct right side up.The retina does basic optical processing, such as edge enhancement and colour separation.The retina is the photo receptive sensory layer of the back of the eye, where the optics of the eye focuses an image of what is in front of the eye. The optic nerve carries signals from the retina to the brain, which interprets them as visual images.The retina has two types of cells the rods and cones. The cones are responsible for colour vision while the rods provide black and white and night vision.Changes the liight rays iinto neural iimpulsesUnce Unce UnceThe retina is responsible for collecting light to create an image
Why do the epidermal cells have had there edges folded over?
The epidermal cells have their edges folded over which is part of the structure. This is as a result of the growth factors which makes the cells to proliferate.
How many rod cells and cone cells in human body?
Rods approximately 125 millions and are spread all over the peripheral retinaCones approximately 6 millions
Why 808 nm laser is red?
Your retina contains three types of colour-sensitivelight-detectingcells (cone cells). Each of these three types of cone cell has a range of frequencies over which it can detect light. If light hitting the retina is only within the frequency range of one type of cone cell, it will be interpreted by the brain as whichever primary colour (red, green or blue) that particular type of cone cell is responsible for detecting. In the case of an 808nm laser, the frequency of the light produced by it is only detected by one type of cone cell in the retina. Nerve impulses from this type of cone are interpreted by the brain as the colour red.This might beg the question of how the eye sees colours which are not primary colours. The way in which this happens is that the frequency response ranges of the three types of cone cells actually overlap each other [See related links below]. Light with a frequency within the response ranges of more than one type of cone cell will be detected by both types of cell. The brain then compares the relative amounts of response from each of these types of cells and interprets this as a particular non-primarycolour. An upshot of this is that, by sending the right ratio of red green and blue light, we can produce the same amounts of response in each type of cone cell as a particular non-primarycolour frequency of light would produce, 'tricking' the brain into thinking that it's actually seeing that frequency of light. This is how the display on your computer screen (RGB display) is able to produce different colours with only red green and blue. When you look at something on the screen which is, for example, orange, you aren't actually seeing orange light, but a mixture of red green and blue light.Aside:808nm wavelength light is actually outside the frequency response of all of the cone cells in your retina. The only reason you can see it is because the laser diode is not perfectly monochromatic; a range of frequencies are produced, with the higher frequencies just inside the frequency response of red-detectingcone cells in your retina.
What is the retina made up of?
the innermost light-sensitive membrane covering the back wall of the eyeball; it is continuous with the optic nerve6 layers of cells that line the back of the eyeball.One layer is sensitive to light and is the first step in turning light into vision.These cells are a part of your brain.The retina is the layer of cells in the back of the eyes responsible for detecting light, which in turn allows you to see. The specific cells responsible for detecting light are the photoreceptors, more commonly referred to as rods and cones.
Where visual images are perceived?
In the primary visual cortex. Information passes from the retina to the bipolar cells, these impulses travel through the optic nerve, which is made up of the axons of ganglion cells, and extend to several regions of the brain including the thalamus. The impulses are then sent further along neurones, to the primary visual cortex, where further processing of the information occurs.
What is different about the region of the retina called the fovea compared with the rest of the retina?
The fovea or fovea centralis that is a pit in the central region of the macula of the retina with a high concentration of cone photoreceptors (red, blue and green) that allows for 100% visual acuity including color vision comprises less than 1% of retinal size but takes up over 50% of the primary visual cortex in the brain.
What Is the Treatment for Retinitis Pigmentosa?
Retinitis pigmentosa is a rare eye disease that affects the retina by creating the light-sensitivity). It basically targets light-sensitive layers of tissue in the back of the eyes. Retinitis pigmentosa breaks down cells connected in the retina gradually over time and causes slow vision loss.
What type of nerve cells on retina that allows you to see dim light?
Rods are the sensory device that detects the illumination. They are over the whole width of the retina. In some animals such as cats, they have a special reflective layer behind the retina so that the sensors have a second go at the light. This feature, and the size of their pupil means that cat's night vision is about six times more sensitive than humans. (But they don't see colour as well as humans.)
Can sharks go blind?
Sharks can only see in shades of grey. Findings from a study by Australian scientists, released in September 2012, show that sharks' eyes have just one type of cone opsin - or light-sensitive proteins found in the photoreceptor cells of the retina - instead of thevtwo or more that are needed to see colour. Cone opsins are used to help animals see in bright light, and to differentiate between colours.
Function of vitreous humor?
It is a clear gel, which fills in the space between the retina and the lens. If it becomne foggy or if it was glazed over it would be harder to send the picture that the eye sees to the optic nerve, which sends it to the brain.
Is liver cancer cirrhosis?
Liver cancer is not the same as liver cirrhosis. Cancer is a replication of malignant (or, "damaged") cells, which gradually take over an organ, reducing the function, and may spread to other parts of the body. (i.e, cancer cells growing and taking over the liver, reducing function). Whereas cirrhosis is vast amounts of scarring to the hepatocytes (liver cells), which make up the liver. (i.e liver cells, which are already in existence, being damaged). Cirrhosis does not spread to other parts of the body.
Explain why cancer is such a dangerous and eventually fatal condition for most who are diagnosed?
Cancer is a disease where parts of your body cells grow uncontrollably and spread to other parts of the body.Cancer is very dangerous because you have no control over it and you can never know when it starts.Cancer is very fatal because doctors and scientiest have treatment but it can always start to fail and it cause death because the cells which we have trillions of get taken over and they take over our white blood cells which are used to fight treatment or bad cells like cancer cells once it takes over our body theirs nothing we can do anymore
A rubber or plastic cone or flare on a bat makes it an altered bat?
A flare or cone is legal as long as it does not extend over the knob itself.
