Basic Anatomy - e
... cells, which are responsible for vision in low light, and cone cells, which are responsible for color vision and detail. In the back of the eye, in the center of the retina, is the macula. In the center of the macula is an area called the fovea centralis. This area contains only cones and is respons ...
... cells, which are responsible for vision in low light, and cone cells, which are responsible for color vision and detail. In the back of the eye, in the center of the retina, is the macula. In the center of the macula is an area called the fovea centralis. This area contains only cones and is respons ...
Ocular stem cells: a status update!
... and subretinal microenvironment modulated differentiation of different cell types [51,52]. These transplanted cells integrate in a temporal-dependent manner that occurs only during rod genesis. Clinical trials using fetal retinal cells have been conducted in patients with retinitis pigmentosa and ag ...
... and subretinal microenvironment modulated differentiation of different cell types [51,52]. These transplanted cells integrate in a temporal-dependent manner that occurs only during rod genesis. Clinical trials using fetal retinal cells have been conducted in patients with retinitis pigmentosa and ag ...
Intraocular Lens Dislocation Cataract surgery
... Macular edema: The term used for swelling in the macula in eyes, or the center part of the retina which is responsible for providing the sharp, straight-ahead vision used for reading and recognizing faces as well as color vision. Peripheral retina: The area outside of the central retina. This inclu ...
... Macular edema: The term used for swelling in the macula in eyes, or the center part of the retina which is responsible for providing the sharp, straight-ahead vision used for reading and recognizing faces as well as color vision. Peripheral retina: The area outside of the central retina. This inclu ...
The Special Senses
... » Cochlea: contains the spiral organ of Corti which is related to hearing » semicircular canals: contains ampulla on semicircular ducts that respond to equilibrium – Membranous labyrinth is a continuous series of sacs and ducts within the bony labyrinth ...
... » Cochlea: contains the spiral organ of Corti which is related to hearing » semicircular canals: contains ampulla on semicircular ducts that respond to equilibrium – Membranous labyrinth is a continuous series of sacs and ducts within the bony labyrinth ...
History of Ophthalmic Photography
... photography was still to come) and for clinical purposes were able to produce accurate enough drawings in a relatively short period of time. For these reasons the photographic methods were looked upon with much scrutiny. By 1899, Dr. Walter Thorner had partly solved the reflex problem with an ophth ...
... photography was still to come) and for clinical purposes were able to produce accurate enough drawings in a relatively short period of time. For these reasons the photographic methods were looked upon with much scrutiny. By 1899, Dr. Walter Thorner had partly solved the reflex problem with an ophth ...
The Sensory System
... the size of the iris’s central opening, the pupil (PU-pil) (Fig. 11-7). One set of fibers is arranged in a circular fashion, and the other set extends radially like the spokes of a wheel. The iris regulates the amount of light entering the eye. In bright light, the iris’s circular muscle fibers cont ...
... the size of the iris’s central opening, the pupil (PU-pil) (Fig. 11-7). One set of fibers is arranged in a circular fashion, and the other set extends radially like the spokes of a wheel. The iris regulates the amount of light entering the eye. In bright light, the iris’s circular muscle fibers cont ...
keratoconjunctivitis should be sus- pected in patients who have ocular
... Figure 1. Ocular fundus and fluorescein angiogram (FA) of case 1. A, The right eye had multiple yellow and white deep retinal lesions with sharp edges of various sizes and configurations in each of the 4 quadrants from the posterior pole to the periphery. B, The left eye had similar fundus findings. ...
... Figure 1. Ocular fundus and fluorescein angiogram (FA) of case 1. A, The right eye had multiple yellow and white deep retinal lesions with sharp edges of various sizes and configurations in each of the 4 quadrants from the posterior pole to the periphery. B, The left eye had similar fundus findings. ...
Changes in glucose level affect rod function more than cone
... Changes in Glucose Level Affect Rod Function More Than Cone Function in the Isolated, Perfused Cat Eye Claudio Macaluso,* Shoken Onoe,t and Gunter Niemeyer The glucose concentration (gl) in mammalian serum incorporates a normal range of variation of several millimoles. We studied the effects of such ...
... Changes in Glucose Level Affect Rod Function More Than Cone Function in the Isolated, Perfused Cat Eye Claudio Macaluso,* Shoken Onoe,t and Gunter Niemeyer The glucose concentration (gl) in mammalian serum incorporates a normal range of variation of several millimoles. We studied the effects of such ...
A Silicone Rubber Tendon for Extraocular Muscle An
... in vivo showed the beginnings of the sheath. Sutures, then, were not essential to long-term fixation; the body provided physiologic fixation. In one case, at reoperation for observation 71 days after the insertion of the prosthesis, the preparation was isolated and the sutures at the globe end were ...
... in vivo showed the beginnings of the sheath. Sutures, then, were not essential to long-term fixation; the body provided physiologic fixation. In one case, at reoperation for observation 71 days after the insertion of the prosthesis, the preparation was isolated and the sutures at the globe end were ...
Leukocoria - Diabetic Retinopathy
... In the early active stages of ROP, a band of glomeruloid capillaries proliferates at the junction between the peripheral nonperfused and the posterior perfused retina. The proliferating vessels break through the internal limiting membrane and invade the vitreous, inciting fibrosis and contraction. I ...
... In the early active stages of ROP, a band of glomeruloid capillaries proliferates at the junction between the peripheral nonperfused and the posterior perfused retina. The proliferating vessels break through the internal limiting membrane and invade the vitreous, inciting fibrosis and contraction. I ...
Publications_files/Rutowski, RL and Warrant, EJ
... Standard procedures for intracellular electrophysiology in insect eyes were used. These are fully described elsewhere (Warrant and McIntyre 1990). Briefly, a butterfly was inserted into a plastic pipette tip whose end had been sliced off to allow the butterfly’s head to pass through. A small quantity of ...
... Standard procedures for intracellular electrophysiology in insect eyes were used. These are fully described elsewhere (Warrant and McIntyre 1990). Briefly, a butterfly was inserted into a plastic pipette tip whose end had been sliced off to allow the butterfly’s head to pass through. A small quantity of ...
David Hubel and Torsten Wiesel - Trin
... Different cells differed from each other in many ways. Some preferred one orientatiom some preferred another, and similarly with the size of the bar, and whether it was bright or dark, and the direction it was moved in. But there was also a major di~ tinction into two types they called simple and co ...
... Different cells differed from each other in many ways. Some preferred one orientatiom some preferred another, and similarly with the size of the bar, and whether it was bright or dark, and the direction it was moved in. But there was also a major di~ tinction into two types they called simple and co ...
VC3_HandoutC - Mount Sinai Hospital
... 4. Provide ongoing assessment of all areas of development and of individual learning styles. For the child with ROP, assessment of learning style is especially critical, to determine the best materials for learning. 5. Help the child to develop good listening skills to supplement his use of remainin ...
... 4. Provide ongoing assessment of all areas of development and of individual learning styles. For the child with ROP, assessment of learning style is especially critical, to determine the best materials for learning. 5. Help the child to develop good listening skills to supplement his use of remainin ...
High Dynamic Range Displays and Low Vision
... example, the average luminance outdoors can be 100 million times greater during the day than at night. The luminance dynamic range at any moment can also be large, with contrasts on the order of 10,000:1 from highlights to shadows. Luminance levels can also change dramatically over time and from pla ...
... example, the average luminance outdoors can be 100 million times greater during the day than at night. The luminance dynamic range at any moment can also be large, with contrasts on the order of 10,000:1 from highlights to shadows. Luminance levels can also change dramatically over time and from pla ...
Configuration of the Four Parasympathetic Ganglia of the Head
... petrous temporal bone), descends through foramen ovule of the skull to join the otic ganglion as its parasympathetic root. The otic ganglion has an additional motor root that arises from the nerve to the medial pterygoid muscle, passes through the ganglion without relay, and then emerges to supply t ...
... petrous temporal bone), descends through foramen ovule of the skull to join the otic ganglion as its parasympathetic root. The otic ganglion has an additional motor root that arises from the nerve to the medial pterygoid muscle, passes through the ganglion without relay, and then emerges to supply t ...
ECronicon
... OFX induces cell cycle arrest of HCEP cells: To postulate the cytotoxic mechanisms of OFX, we then detected the cell cycle progression of HCEP cells by FCM using PI staining. Our results showed that the number of HCEP cells at G1 phase decreased with time (P < 0.01), that at S phase increased with t ...
... OFX induces cell cycle arrest of HCEP cells: To postulate the cytotoxic mechanisms of OFX, we then detected the cell cycle progression of HCEP cells by FCM using PI staining. Our results showed that the number of HCEP cells at G1 phase decreased with time (P < 0.01), that at S phase increased with t ...
The Sensory Organs
... The first layer consists of nerve axons that collect at the optic disk and pass through the sclera to form the optic nerve Ganglion cells Bipolar neurons Rod cells Cone cells ...
... The first layer consists of nerve axons that collect at the optic disk and pass through the sclera to form the optic nerve Ganglion cells Bipolar neurons Rod cells Cone cells ...
NEURO-OPHTHALMOLOGY: EXAMINATION AND INVESTIGATION
... enough in the absence of evidence suggesting that any one way was better than another. Recently, however, Pandit et al2 have compared the various techniques in a prospective manner. They found that by far the most sensitive technique was the use of a small (5 mm) red target, specifically asking the ...
... enough in the absence of evidence suggesting that any one way was better than another. Recently, however, Pandit et al2 have compared the various techniques in a prospective manner. They found that by far the most sensitive technique was the use of a small (5 mm) red target, specifically asking the ...
CASE 8
... one of the most important assessments to make in a patient complaining of decreased vision is whether it is due to an ocular problem or to a ...
... one of the most important assessments to make in a patient complaining of decreased vision is whether it is due to an ocular problem or to a ...
Localization of insulin-like growth factor-1 binding sites in the
... The embryonic chicken lens has provided a useful model with which to study the factors that control lens fiber cell differentiation. Primary explains of epithelial cells from the lenses of 6-day-old embryos undergo many of the changes characteristic of fiber cell formation when exposed to IGF-1,7 in ...
... The embryonic chicken lens has provided a useful model with which to study the factors that control lens fiber cell differentiation. Primary explains of epithelial cells from the lenses of 6-day-old embryos undergo many of the changes characteristic of fiber cell formation when exposed to IGF-1,7 in ...
Spring 2013
... and pediatric patients with retinal disorders and conditions that impact other structures of the posterior segment of children’s eyes. Dr. Wenick’s research focuses on the study of the interaction of the retina with the vitreous gel of the eye. While we are just beginning to understand the specifics ...
... and pediatric patients with retinal disorders and conditions that impact other structures of the posterior segment of children’s eyes. Dr. Wenick’s research focuses on the study of the interaction of the retina with the vitreous gel of the eye. While we are just beginning to understand the specifics ...
The Operational Strengths and Weaknesses of Military Night Vision
... drivers trying to locate these emplacements using night vision equipment (US Army Centre for Lessons Learned, 2001). Image intensification systems can be affected by external light sources. For example, there is also a risk that personnel will fixate on external light sources such as city lights. At ...
... drivers trying to locate these emplacements using night vision equipment (US Army Centre for Lessons Learned, 2001). Image intensification systems can be affected by external light sources. For example, there is also a risk that personnel will fixate on external light sources such as city lights. At ...
Differentiation of Induced Pluripotent Stem Cells to Lentoid
... P19), hypothesizing that the feeder will provide a niche for ectoderm and lens cell differentiation. Differentiation into lens cells should result in re-activation of the Cryaa-tdTomato reporter. doi:10.1371/journal.pone.0157570.g001 ...
... P19), hypothesizing that the feeder will provide a niche for ectoderm and lens cell differentiation. Differentiation into lens cells should result in re-activation of the Cryaa-tdTomato reporter. doi:10.1371/journal.pone.0157570.g001 ...
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.