5 types of sensory receptors are: chemoreceptor A sense organ, or one of its cells (such as those for the sense of taste or smell), that can respond to a chemical stimulus; a chemosensor. mechanoreceptor Any information about mechanical changes in its environment, such as movement, tension and pressure. photoreceptor A specialized neuron able to detect, and react to light nociceptor A sensory receptor that sends signals that cause the perception of pain in response to a potentially damaging stimulus. thermoreceptor A nerve cell that is sensitive to changes in temperature A sensation is : A physical feeling or perception resulting from something that happens to or comes into contact with the body. …show more content…
Some drugs affect pupils. Amphetamines (speed, meth) can dilate them, for example, while opiates (heroin) can constrict them. Cornea, Sclera, Choroid, Ciliary Body, Suspensory ligament, lens, iris, pupil, retina, fovea centralis The optic nerve has to enter the confines of the eye somewhere in order to innervate the retina. Where it enters has no rods and cones (the very nerve endings of the optic nerve which allow us to see). Therefore, this is a "blind spot." There are two types of photoreceptors in the human retina, rods and cones. Rods are responsible for vision at low light levels (scotopic vision). They do not mediate color vision, and have a low spatial acuity. Cones are active at higher light levels (photopic vision), are capable of color vision and are responsible for high spatial acuity. The central fovea is populated exclusively by cones. There are 3 types of cones which we will refer to as the short-wavelength sensitive cones, the middle-wavelength sensitive cones and the long-wavelength sensitive cones or S-cone, M-cones, and L-cones for
A.accommodation B.the concentration of cones in the fovea C.chemical structure of the vitreous humor D.the prevalence of amacrine cells in the
After being shown a picture of an elephant they eye will take the light that is reflected from the object and it will enter the eye through the pupil. Then the light will be focused by the cornea and the lens to form a sharp image of the elephant in the retina. The retina is the network of neurons that cover the back of the eye and contains the visual receptors for a person vision. The visual receptors are made up of cones and rods that contain light sensitive chemicals called visual pigments. Visual pigments reacht to light and cause a triggered electrical signals to occur. These electrical signals will then flow through a network of neurons and this network of neurons is what makes up a persons retina. After the flow through the network of neurons occurs the electrical signals will emerge from the back of the eye in the area
Also, on the retina is the optic disk. There are no photoreceptors in this area, so any light that falls on this part of the retina is unseen and creates what is called the blind spot. (Hugh
Focusing an image clearly onto the retina is the initial step in the process of vision, but although a sharp image on the retina is essential for clear vision, a person does not see the picture on the retina. Vision occurs not in the retina, but in the brain. Before the brain can create vision, the light on the retina must activate the visual receptors in the retina by a two-element
A mechanoreceptor in the papillary layer of the dermis that responds to fine touch is a
The eyelids are made up of four layers, the skin, muscle, connective tissue and conjunctiva. The process of vision occurs when light waves from an object, enter through the iris. Light then passes through the lens of the eye, a double convex structure that is used to focus the light, and then reaches the retina. Inside the retina are rods and cones. Rods are used to sense light and dark, and cones are used for sensing colors. Whether the light entering the eye hits the cones or rods, a signal is sent across the optic nerve to the brain where it is processed and viewed as an image. Some issues people have with eyesight are as follows. Those who are farsighted are unable to see things clearly at a short distance, compared to a long distance. This occurs when the light that enters the eye is focused behind the retina, and not directly onto it. When the cornea is not curved enough, this happens. Nearsightedness is when one can see objects clear at a short distance, but not at a longer distance, and this is often caused by a change in the cornea. A Blind spot is the location the optic disk, where the optic nerve fiber exits, and at this location there are no cones or rods, so there is a blind spot.
Humans have three cone cells that are extremely sensitive to Red, (620-700nm), Green (490-570nm) and Blue (450-495nm) wavelengths of light. Although these three cones are most sensitive to these wavelengths, they are still sensitive to the remaining wavelengths of visible light between 400-700nm. When a light with a wavelength of 600nm is transmitted through the retina, the Red and Green cones capture, sense and signal the brain that orange light is observed. In this case the Red and Green cones absorb light but the Green cones are less sensitive. Also, the Blue cones don’t absorb much light and are not sensitive
-Sensory receptors are either interoceptors (detect stimuli in the body) or exteroceptors (detect stimuli outside the body).
Pain is something that connects all of us. From birth to death we can identify with each other the idea and arguably the perception of it. We all know we experience it, but what is more important is how we all perceive it. It is known that there are people out there with a ‘high’ pain tolerance and there are also ones out there with a ‘low’ pain tolerance, but what is different between them? We also know that pain is an objective response to certain stimuli, there are neurons that sense and feel pain and there are nerve impulses that send these “painful” messages to the brain. What we don’t know is where the pain
However, there are other processes that are involved before the living organism produces a perception from a physical sensation. Other sensory organs and systems include: the eye and visual system, ears and auditory system, the nose and olfaction, taste-buds or tongue and gustation, somesthetic sense and warning and reminding
The sensation is the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. Perception is the process or organizing and interpreting sensory information, enabling us to recognize meaningful objects and events. Organisms
The optic nerve reaches from behind the eyes to the occipital lobe where this visual information can finally be interpreted into what we know as ‘seeing something’. It is at this point that it is useful as this is when colours can be perceived (Breedlove, 2010).