Basic structures of the eye
... Image on the L side of the visual field (red) is focused on the R side of the retina in both eyes (red). All the nerve fibre in the nasal retina of the L eye (carrying the signal from the L visual field) cross over to join the temporal retina fibre of the R eye (also carrying signal of the L visual ...
... Image on the L side of the visual field (red) is focused on the R side of the retina in both eyes (red). All the nerve fibre in the nasal retina of the L eye (carrying the signal from the L visual field) cross over to join the temporal retina fibre of the R eye (also carrying signal of the L visual ...
Pupils and Near Vision
... • Radially oriented dilator (actually a myo-epithelium) - like the spokes of a wagon wheel • Sphincter/constrictor ...
... • Radially oriented dilator (actually a myo-epithelium) - like the spokes of a wagon wheel • Sphincter/constrictor ...
LISC 322 Neuroscience Normal Vision Retinal Image Formation
... The hallmarks of Retinitis Pigmentosa are night blindness, narrowing of the retinal blood vessels, and the migration of pigment from disrupted retinal pigment epithelium into the retina, forming clumps of various sizes. ...
... The hallmarks of Retinitis Pigmentosa are night blindness, narrowing of the retinal blood vessels, and the migration of pigment from disrupted retinal pigment epithelium into the retina, forming clumps of various sizes. ...
Cranial Nerves According to Functional Components
... SPECIAL SOMATIC AFFERENT (SSA) II. Optic: Optic stimuli are received by the rods and cones, relayed to second and third order neurons which comprise the optic nerve. (About half the fibers decussate in the optic chiasma). Impulses are along the optic nerve and optic tract to the latera ...
... SPECIAL SOMATIC AFFERENT (SSA) II. Optic: Optic stimuli are received by the rods and cones, relayed to second and third order neurons which comprise the optic nerve. (About half the fibers decussate in the optic chiasma). Impulses are along the optic nerve and optic tract to the latera ...
HONORS PSYCHOLOGY REVIEW QUESTIONS
... parts of the ear so that the sound stimulus can lead to the experience of hearing? A) outer ear B) basilar membrane C) cochlea D) auditory nerve 3. Physiological research in the 1950s and 1960s showed that: A) trichromatic theory is correct and opponent-process theory is incorrect. B) opponent-proce ...
... parts of the ear so that the sound stimulus can lead to the experience of hearing? A) outer ear B) basilar membrane C) cochlea D) auditory nerve 3. Physiological research in the 1950s and 1960s showed that: A) trichromatic theory is correct and opponent-process theory is incorrect. B) opponent-proce ...
High Energy Visible Light (HEVL) and Potential
... color vision perception -especially in dim light. By blocking too much blue light we might also affect our sleep cycles. So the main areas of HEVL blocking (high frequency blue and violet) are what we’ll review. Two inventions currently available that address this are BluTech Lenses and Crizal Preve ...
... color vision perception -especially in dim light. By blocking too much blue light we might also affect our sleep cycles. So the main areas of HEVL blocking (high frequency blue and violet) are what we’ll review. Two inventions currently available that address this are BluTech Lenses and Crizal Preve ...
L7 - Special senses - Moodle
... Holly Fischer (2013) Http://commons.wikimedia.org/wiki/File:Three_Main_Layers_of_the_Eye.png?uselang=en-gb ...
... Holly Fischer (2013) Http://commons.wikimedia.org/wiki/File:Three_Main_Layers_of_the_Eye.png?uselang=en-gb ...
Hereditary Retinal Dystrophies
... Presentation - symptoms may start within the first two decades of life. Visual acuity deteriorates when the 'egg-yolk lesion' ruptures. Changes occur in EOG readings in children before they are symptomatic. Vision may be only slightly decreased in childhood and teenage years when the 'eggyolk lesion ...
... Presentation - symptoms may start within the first two decades of life. Visual acuity deteriorates when the 'egg-yolk lesion' ruptures. Changes occur in EOG readings in children before they are symptomatic. Vision may be only slightly decreased in childhood and teenage years when the 'eggyolk lesion ...
7-1 CHAPTER 7 VISION hotoreception is a particularly important
... not consider this further because it plays no In many people the vitreous is not role in the majority of normal human vision. completely clear, but contains particulate matter that is not transparent. This material may be stationery or may float around, producing "spots before the eyes,” the floatin ...
... not consider this further because it plays no In many people the vitreous is not role in the majority of normal human vision. completely clear, but contains particulate matter that is not transparent. This material may be stationery or may float around, producing "spots before the eyes,” the floatin ...
Structure and Function of the Eye - Center for Teaching and Learning
... The Refractive Structures ...
... The Refractive Structures ...
Senses Notes
... must hit the same spot of the retina on both eyes to see only one object Both eyes are directed on the object at the ...
... must hit the same spot of the retina on both eyes to see only one object Both eyes are directed on the object at the ...
Sensory Receptors - Calgary Christian School
... cochlea – used for hearing, this is where mechanical energy of sound is converted to electrochemical impulses that are transmitted to the brain The inner ear is filled with fluid and vibrations in the oval window are converted to pressure waves in the fluid The cochlea can be divided into the organ ...
... cochlea – used for hearing, this is where mechanical energy of sound is converted to electrochemical impulses that are transmitted to the brain The inner ear is filled with fluid and vibrations in the oval window are converted to pressure waves in the fluid The cochlea can be divided into the organ ...
Chapter 12
... vitreous body. This supports the internal parts of the eye and helps maintain its shape. 39. Distinguish between the macula lutea and optic disk. The macula lutea is a small spot on the retina. In its center is a depression called the fovea centralis, which has the sharpest vision. The optic disk is ...
... vitreous body. This supports the internal parts of the eye and helps maintain its shape. 39. Distinguish between the macula lutea and optic disk. The macula lutea is a small spot on the retina. In its center is a depression called the fovea centralis, which has the sharpest vision. The optic disk is ...
Chapter 12
... the vitreous body. This supports the internal parts of the eye and helps maintain its shape. 39. Distinguish between the macula lutea and optic disk. The macula lutea is a small spot on the retina. In its center is a depression called the fovea centralis, which has the sharpest vision. The optic dis ...
... the vitreous body. This supports the internal parts of the eye and helps maintain its shape. 39. Distinguish between the macula lutea and optic disk. The macula lutea is a small spot on the retina. In its center is a depression called the fovea centralis, which has the sharpest vision. The optic dis ...
Live Cells as Optical Fibers in the Vertebrate Retina
... INL; ganglion cell layer, GCL), two layers, connecting the nuclear layers, contain cellular processes and the neuronal synapses (the outer plexiform layer, OPL, and the inner plexiform layer, IPL), the innermost layer contains the axons of the ganglion cells on their course towards the optic nerve h ...
... INL; ganglion cell layer, GCL), two layers, connecting the nuclear layers, contain cellular processes and the neuronal synapses (the outer plexiform layer, OPL, and the inner plexiform layer, IPL), the innermost layer contains the axons of the ganglion cells on their course towards the optic nerve h ...
How does the nervous system work? Key Points Part I I. Cells of the
... 2. enzyme deactivation – specific enzyme changes structure of neurotransmitter so it is not recognized by receptor 3. glia cells – astrocytes remove neurotransmitters from synaptic cleft 4. reuptake – whole neurotransmitter molecule is taken back into axon terminal that released it a. this is a comm ...
... 2. enzyme deactivation – specific enzyme changes structure of neurotransmitter so it is not recognized by receptor 3. glia cells – astrocytes remove neurotransmitters from synaptic cleft 4. reuptake – whole neurotransmitter molecule is taken back into axon terminal that released it a. this is a comm ...
Ocular Anatomy - Texas Optometric Association
... The “film of the camera” Contains photoreceptors – rods and cones 2 basic layers – neural retina and RPE Retinal Layers Retina Clinical Notes Retinal Detachment Is an Emergency That Needs Treatment to Restore the Blood Supply As Quickly As Possible ...
... The “film of the camera” Contains photoreceptors – rods and cones 2 basic layers – neural retina and RPE Retinal Layers Retina Clinical Notes Retinal Detachment Is an Emergency That Needs Treatment to Restore the Blood Supply As Quickly As Possible ...
Nervous System Lab Glial cells Neuron
... olfactory bulbs would be larger or smaller (in proportion to the size of the brain) than those of the sheep brain? ________________________________________________ The optic nerves enter the brain just after a region called the optic chiasma, where some of the visual fibers “cross-over” to the oppos ...
... olfactory bulbs would be larger or smaller (in proportion to the size of the brain) than those of the sheep brain? ________________________________________________ The optic nerves enter the brain just after a region called the optic chiasma, where some of the visual fibers “cross-over” to the oppos ...
IOSR Journal of Electronics and Communication Engineering (IOSR-JECE)
... 2.1.3 Optic nerve output The optic nerve in humans contains roughly one million individual fibers, each of which is an outgrowth of a third order neuron of the retina called a ganglion cell. In general, ganglion cells are functionally connected to many rods and cones by means of intermediate, second ...
... 2.1.3 Optic nerve output The optic nerve in humans contains roughly one million individual fibers, each of which is an outgrowth of a third order neuron of the retina called a ganglion cell. In general, ganglion cells are functionally connected to many rods and cones by means of intermediate, second ...
lecture fourteen – senses
... (1) Pigmented retina - outer pigmented layer - reduces light scattering inside eye (2) Sensory retina - inner layer of rod and cone cells that are sensitive to light - rods are very sensitive to light and function in dim light but don’t do color - cones require more light but do discriminate color ( ...
... (1) Pigmented retina - outer pigmented layer - reduces light scattering inside eye (2) Sensory retina - inner layer of rod and cone cells that are sensitive to light - rods are very sensitive to light and function in dim light but don’t do color - cones require more light but do discriminate color ( ...
WAVES AND ELECTROMAGNETIC RADIATION
... • 'How an infinity of rays from each point in the visual field is drawn into a coherent, point-to-point correspondence in the eye.' Against tradition, Kepler argued that the crystalline lens re-focused intromitted rays on the retina where vision was made possible. Significantly, Kepler called this i ...
... • 'How an infinity of rays from each point in the visual field is drawn into a coherent, point-to-point correspondence in the eye.' Against tradition, Kepler argued that the crystalline lens re-focused intromitted rays on the retina where vision was made possible. Significantly, Kepler called this i ...
Eye examination
... – The tear film and cornea, iris – Aqueous : abnormal cell (red or white blood cell, pigment granules), turbidity (flare-protein↑) – Anterior vitreous : dilated pupil, crystalline lens ...
... – The tear film and cornea, iris – Aqueous : abnormal cell (red or white blood cell, pigment granules), turbidity (flare-protein↑) – Anterior vitreous : dilated pupil, crystalline lens ...
Photoreceptor cell
A photoreceptor cell is a specialized type of neuron found in the retina that is capable of phototransduction. The great biological importance of photoreceptors is that they convert light (visible electromagnetic radiation) into signals that can stimulate biological processes. To be more specific, photoreceptor proteins in the cell absorb photons, triggering a change in the cell's membrane potential.The two classic photoreceptor cells are rods and cones, each contributing information used by the visual system to form a representation of the visual world, sight. The rods are narrower than the cones and distributed differently across the retina, but the chemical process in each that supports phototransduction is similar. A third class of photoreceptor cells was discovered during the 1990s: the photosensitive ganglion cells. These cells do not contribute to sight directly, but are thought to support circadian rhythms and pupillary reflex.There are major functional differences between the rods and cones. Rods are extremely sensitive, and can be triggered by a single photon. At very low light levels, visual experience is based solely on the rod signal. This explains why colors cannot be seen at low light levels: only one type of photoreceptor cell is active.Cones require significantly brighter light (i.e., a larger numbers of photons) in order to produce a signal. In humans, there are three different types of cone cell, distinguished by their pattern of response to different wavelengths of light. Color experience is calculated from these three distinct signals, perhaps via an opponent process. The three types of cone cell respond (roughly) to light of short, medium, and long wavelengths. Note that, due to the principle of univariance, the firing of the cell depends upon only the number of photons absorbed. The different responses of the three types of cone cells are determined by the likelihoods that their respective photoreceptor proteins will absorb photons of different wavelengths. So, for example, an L cone cell contains a photoreceptor protein that more readily absorbs long wavelengths of light (i.e., more ""red""). Light of a shorter wavelength can also produce the same response, but it must be much brighter to do so.The human retina contains about 120 million rod cells and 6 million cone cells. The number and ratio of rods to cones varies among species, dependent on whether an animal is primarily diurnal or nocturnal. Certain owls, such as the tawny owl, have a tremendous number of rods in their retinae. In addition, there are about 2.4 million to 3 million ganglion cells in the human visual system, the axons of these cells form the 2 optic nerves, 1 to 2% of them photosensitive.The pineal and parapineal glands are photoreceptive in non-mammalian vertebrates, but not in mammals. Birds have photoactive cerebrospinal fluid (CSF)-contacting neurons within the paraventricular organ that respond to light in the absence of input from the eyes or neurotransmitters. Invertebrate photoreceptors in organisms such as insects and molluscs are different in both their morphological organization and their underlying biochemical pathways. Described here are human photoreceptors.