Introduction: Photoreceptors are specialized neurons in the eye “retina” due to them having the role of photo-transduction which is the conversion of light to electrical signals which reach to the rod, cone, and photosensitive ganglion cells in the back of the eye via retina. The visual cycle is the biological is basically the conversion from photons into electrical signals that are sent to the brain through the retina as a receptor. The vital biological importance of the photoreceptors is the conversion of light to signals that can stimulate biological processes and the perception of the sight sense. In more details, the photoreceptor proteins have a role in the triggering of the change in the cell’s membrane potential.
The rod
There are 3 different types of cone cells in the human retina “the L, M, and S cones” that can respond only in certain wavelengths of light “short, medium, and long lengths”. Through the opponent process the color experience is measured from those three distinctive signals. With the knowledge of the univariance principle, we need to always take into account that the firing cells always depend on the number of photons absorbed. The three responses of the three different cones are determined by the respective photoreceptor proteins having the ability to absorb the photons of the many different wave lengths on light. So, for example, an S cone cell contains a photoreceptor protein that more readily absorbs short wavelengths of light (i.e., more "blue"). Light of a longer wavelength can also produce the same response, but it must be much darker to do
Cones are all concentrated at on area which is the fovea, meanwhile the rods are dense in all areas and not centered in the macula latea resulting in a wider visual spectrum. Another factor is that rods are much more sensitive than all types of cones. For instance, a human can perceive a human’s body shape and movement without colors in dark light levels due to the rods being stimulated rather than cones.
2.1) Effect of Genders on Rods and Cones
“It is generally admitted that with woman the powers of intuition, of rapid perception and perhaps of imitation, are more strongly marked than in man: but some, at least, of these faculties are characteristic of the lower races, and therefore of a pas” – Charles Darwin
Can we link that women have better sense of smell and taste than men and imply it to sight. Because as proven, females stimulate sense of smell and taste better than men thus leading the females to be a priority when chosen for a taste/odour tester
Darwin was a product of his time and with his time came the ideas of sexism and racism which were clearly integrated into his theories. There are some facets of Darwin’s theory about the differences in men and women which can be explained by biology but overall, it is clear that his theory is based on the sexist ideas prevalent in the 1800s. Women are expected to be caring, selfless, maternal, and submissive while men are expected to be dominant, aggressive, successful and confident. Most of Darwin’s theory relating to the differences in men and women can be explained by social expectations which have shaped what is acceptable in society.
Colors of cretin things can appear different at some situations. For example, blood as we know it is red, that color that you see through your eyes of the blood in our veins is “red” but underwater, at 30 feet underneath the surface your blood turns, or rather appears green due to the light bouncing off of it is much less than it is at the surface as mentioned in the article “Did you know that your blood is green underwater?” by Fun Facts (see Article 2). These examples got me interested from the class discussions we had and how the philosophers viewed sense perception and the kind of thought they had of
Men and women differ physically, emotionally and mentally. However, these differences has an advantage. The difference in physical appearances allows men to be attracted to females, and women to be attracted to males. The different emotional beings permit men and women to depend on each other for comfort at times of sadness, anger, happiness and many other emotions. Mentally, men and women think very differently, but this difference accounts for a gender to be curious and wanting to find out how the opposite sex thinks. Analyzing the difference in behaviors in both males and females, judging from effects of the brain, effects of inherited genes, in comparison to the effects of the environment and surroundings, reveals that the vast differences in males and females results from the effects of
With the advent of this new technology doctors and psychiatrists may have finally reached the light at the end of the tunnel. Well not exactly, but the state of the art new technology, Optogenetics, does offer an innovative new approach to the study of the brain, and, more importantly, the treatment of patients. The use of light had been surmised to be a valuable way to control cells many years prior by Francis Crick (Crick 2024), but no one had been able to pull all the pieces together. While it’s by no means perfectly safe: there are still uncertainties about the long-term effects and the level of specificity it offers can only control groups of neurons up to .3 (mm^3) instead of individual neurons. Optogenetics still provides benefits over our current pharmaceutical and surgical technologies with its specificity, both temporally and spatially. In light of these facts, doctors should consider optogenetics as a safe and efficacious way to treat neurological disorders unresponsive to current methods.
Currently, it is still unknown how different men and women really are, at least in the aspect regarding the brain and one’s thought processes. It is a controversial topic, just being discovered and many studies conflict with each other regarding the subject, which leaves for open questions and missing answers. Originally, there was a common understanding that at least cognitively, both genders were born similar. The way their environment affected them was what made them different, and the society surrounding them believably had the largest impact on the difference of an individual. In contrast however, studies in recent times conflict with these older beliefs revealing quite the opposite. Some of today's psychologists agree that a few differences exhibited by male and female brains are innate (Khazan). To be specific, each gender has been found to have correlations in the way they both navigate. Men are more likely in dealing with directions to go about it in a cardinal fashion, using an innate, spatial ability to guide themselves. They rely on specific directions and knowledge in order to correctly know exactly where they are or what they are looking for is in relation to their environment. While females typically navigate memorizing landmarks to travel (Navigational Differences). There are many different theories concerning as to why both genders may have this relation, and as of now they are still being looked into with highly successful studies. As time passes, more and more of these studies are revealing information about the brain, and innate differences among it and the genders. Evidence proves that since the day they are born men and women are different mentally, specifically in the way of navigating and following directi...
The socio-biological theory suggests gender appropriate behaviour has evolved to allow humanity to survive. There is supporting evidence in the composition of the human body; men have a larger lung capacity and greater physical strength than women in order to better equip them for protecting their family. In contrast, women are born with child-bearing capacities and are therefore biologically predetermined to care for their children, thus ensuring the human race survives.
And the retina. These are all on the wall of the eyeball, the fibrous tunic consist of
An inspection of the modern animal phyla will reveal that eyes are just as diverse as they are complex. Some organisms like the rag worm have pigmented cup eyes while other like he box jellyfish have two lens eyes and two pairs of pigment pit eyes. To account for the diversity in eye structure, we must first examine the eye ‘prototype’, the original structure that was acted upon by evolution. The simplest organ that can be considered an eye is composed of a single photoreceptor cell and a single pigment cell, without any lens or other refractive body (Arendt, 2003). Such organs are know as eyespots, and...
Color Vision Development in Infants: The Responsibility of Cone Types and Wavelength in Order of Color Development
There is an abundance of ways light and color can play tricks with how your body thinks. Color has an impact on everything. When you walk into a restaurant and instantly become hungry is one way that color has an influence. When you feel antsy in one room and calm in the other is another way that color has an effect, this is all because of the atmosphere of that room, which is altered by color.
Light is what lets you experience colour. The pigment of the retina in your eyes is sensitive to different lengths of light waves which allows you to see different colours. The wavelengths of light that humans can see are called the visible colour spectrum.
One sub-system under the sensory system is the visual system; the main sense organs of this are the eyes. The eye is the sensory organ that allows us to detect light from external stimuli. When a light ray is detected, the eye converts these rays into electrical signals that can be sent to the brain in order to process the information and giv...
Visual perception plays a big part on how we perceive life. If we didn't have perception I don't know where we would be now.
The human eye has a natural blind spot that is completely unavoidable. This spot is where the optic nerve, sending what is being seen, connects to the brain. This nerve passes through the retina causing what is called the “blind spot”. The “blind spot” is a hole being created in the light sensitive tissue. While the image being seen is being sent to the brain it will
This reflected light passes through the lens and falls on to the retina of the eye. Here, the light induces nerve impulses that travel through the optic nerve to the brain, where it makes an image of the object, and then that image is passed on to muscles and glands.The eye is well protected. It lies within a bony socket of the skull. The eyelids guard it in front. They blink an average of once every six seconds. This washes the eye with the salty secretion from the tear, or lachrymal, glands.