Seeing, Hearing, and Smelling the World
... scientists to discover just how receptor neurons respond to light, to vibrations in the air, to odorant molecules, or to other stimuli. The receptor neurons in each sensory system deal with different kinds of energy—electromagnetic, mechanical, or chemical. The receptor cells look different from one ...
... scientists to discover just how receptor neurons respond to light, to vibrations in the air, to odorant molecules, or to other stimuli. The receptor neurons in each sensory system deal with different kinds of energy—electromagnetic, mechanical, or chemical. The receptor cells look different from one ...
Eye & Ear - WordPress.com
... The oculomotor nerve innervates the inferior oblique. The oculomotor nerve innervates the superior and inferior rectus muscles. The oculomotor nerve [III] innervates the medial rectus, and the abducent nerve [VI] innervates the lateral rectus. The trochlear nerve [IV] innervates the superior obliqu ...
... The oculomotor nerve innervates the inferior oblique. The oculomotor nerve innervates the superior and inferior rectus muscles. The oculomotor nerve [III] innervates the medial rectus, and the abducent nerve [VI] innervates the lateral rectus. The trochlear nerve [IV] innervates the superior obliqu ...
Soluble Tumor Necrosis Factor Alpha Promotes Retinal Ganglion
... necrosis factor α (TNFα) signaling has been linked to RGC damage, however, the mechanism by which TNFα promotes neuronal death remains poorly defined. Using an in vivo rat glaucoma model, we show that TNFα is upregulated by Müller cells and microglia/macrophages soon after induction of ocular hypert ...
... necrosis factor α (TNFα) signaling has been linked to RGC damage, however, the mechanism by which TNFα promotes neuronal death remains poorly defined. Using an in vivo rat glaucoma model, we show that TNFα is upregulated by Müller cells and microglia/macrophages soon after induction of ocular hypert ...
Debilitating Eye Diseases
... Severe loss of visual acuity Marked tortuosity & engorgement of retinal veins Retinal hemorrhages, Cotton wool spots Severe optic disc edema & hyperemia Visual acuity is permanently impaired Monthly follow-up for 6 months (+) neovascularization – PRP treatment Tx of associated medical ...
... Severe loss of visual acuity Marked tortuosity & engorgement of retinal veins Retinal hemorrhages, Cotton wool spots Severe optic disc edema & hyperemia Visual acuity is permanently impaired Monthly follow-up for 6 months (+) neovascularization – PRP treatment Tx of associated medical ...
Eye Case Studies Sean Every
... • The master class in testing pupils. • The swinging flashlight test. • Highlights subtle pathology in retina or optic nerve – Positive test when pupil dilates with light ...
... • The master class in testing pupils. • The swinging flashlight test. • Highlights subtle pathology in retina or optic nerve – Positive test when pupil dilates with light ...
I Clinical Retinopathy DIGEST 8
... mechanisms underlying the migration of these cells remain unclear, and so far there seem to have been no adverse events associated with their use. This all makes MSCs a promising source of stem cells for tissue repair and gene therapy. So why is the eye a potential candidate site? There are a number ...
... mechanisms underlying the migration of these cells remain unclear, and so far there seem to have been no adverse events associated with their use. This all makes MSCs a promising source of stem cells for tissue repair and gene therapy. So why is the eye a potential candidate site? There are a number ...
The Color of Lights: More Than Meets the Eye
... amount of light emitted at any particular range of wavelengths is difficult from looking at a photo of the spectrum itself (on the top in the illustration to the left); to do this accurately, we need to plot the actual energy intensity of each wavelength in a spectral energy distribution graph (show ...
... amount of light emitted at any particular range of wavelengths is difficult from looking at a photo of the spectrum itself (on the top in the illustration to the left); to do this accurately, we need to plot the actual energy intensity of each wavelength in a spectral energy distribution graph (show ...
Response properties and, receptive fields of cells in an anatomically
... no response to movement nor did movement 180 ° from the preferred direction. These cells responded only to slow movement across the receptive field and the optimum speed ranged from 1 to 5°/sec. Cells responded continuously provided the stimulus was moving and poorly or not at all to stationary stim ...
... no response to movement nor did movement 180 ° from the preferred direction. These cells responded only to slow movement across the receptive field and the optimum speed ranged from 1 to 5°/sec. Cells responded continuously provided the stimulus was moving and poorly or not at all to stationary stim ...
receptive fields of cells in striate cortex of very young, visually
... was little or no response. The unit from which the sma .ller spikes were recorded gave hardly any responses to stimulation of the right eye (which had been covered), but responded well to the left. On the contrar Y, the cell giving the larger stpikes strongly preferred the eye t lhat had been occlud ...
... was little or no response. The unit from which the sma .ller spikes were recorded gave hardly any responses to stimulation of the right eye (which had been covered), but responded well to the left. On the contrar Y, the cell giving the larger stpikes strongly preferred the eye t lhat had been occlud ...
doc ntc - We moved
... A layered structure has 6 layers o Layers 6, 4, and 1 receive fibers from contralateral eye o Layers 5, 3, and 2 receive from ipsilateral eye o Layers are retina-specific o Outer 4 layers are parvocellular (small cells) o Inner 2 layers are magnocellular (large cells) Parvocellular layers receive ...
... A layered structure has 6 layers o Layers 6, 4, and 1 receive fibers from contralateral eye o Layers 5, 3, and 2 receive from ipsilateral eye o Layers are retina-specific o Outer 4 layers are parvocellular (small cells) o Inner 2 layers are magnocellular (large cells) Parvocellular layers receive ...
pp_Direct-Ophthalmoscopy_en
... Only way (and place in the body) that veins and arteries can be seen in their natural state, noninvasively. Part of general optical screening where direct observation of the structures of the fundus may ...
... Only way (and place in the body) that veins and arteries can be seen in their natural state, noninvasively. Part of general optical screening where direct observation of the structures of the fundus may ...
Shaken Baby Syndrome
... the size and degree of bleeding that occurs. The effects may include: Blurred vision Light flashes Floaters that may be dark or red Loss of vision Depending on the severity of the vitreous hemorrhage, it may take several months or significantly longer for the body to reabsorb the blood and f ...
... the size and degree of bleeding that occurs. The effects may include: Blurred vision Light flashes Floaters that may be dark or red Loss of vision Depending on the severity of the vitreous hemorrhage, it may take several months or significantly longer for the body to reabsorb the blood and f ...
ANATOMY AND PHYSIOLOGY OF THE EYE
... • The nerve layer is the retina. It is the innermost layer of the eye and is a direct extension of the brain and is normally transparent. The attachments are most firm at the ora serrata and around the optic nerve head (optic disc). When injured, it cannot repair itself. An injured retina, such as a ...
... • The nerve layer is the retina. It is the innermost layer of the eye and is a direct extension of the brain and is normally transparent. The attachments are most firm at the ora serrata and around the optic nerve head (optic disc). When injured, it cannot repair itself. An injured retina, such as a ...
DISSECTION EXERCISE: COW EYE Introduction:
... that passes through the retina and contains blood vessels tat nourish the eye. Anteriorly, the ciliary body forms a ring of muscle that controls the shape of the lens, which is suspended from the ciliary body by the suspensory ligaments (ciliary zonules). The iris also contracts and relaxes changing ...
... that passes through the retina and contains blood vessels tat nourish the eye. Anteriorly, the ciliary body forms a ring of muscle that controls the shape of the lens, which is suspended from the ciliary body by the suspensory ligaments (ciliary zonules). The iris also contracts and relaxes changing ...
Ophthalmology - Certified Medical Educators
... applicator, do not patch eye. Metal FB needs rust ring removed. Corneal abrasion – eye scratch Sx: severe pain & photophobia Tx: analgesics, polymyxinbacitracin ointment Hyphema – hemorrhage in anterior chamber, worry about pressure increases & permanent visual loss. Avoid blood thinners. Retinal de ...
... applicator, do not patch eye. Metal FB needs rust ring removed. Corneal abrasion – eye scratch Sx: severe pain & photophobia Tx: analgesics, polymyxinbacitracin ointment Hyphema – hemorrhage in anterior chamber, worry about pressure increases & permanent visual loss. Avoid blood thinners. Retinal de ...
T35 Lab Activities for 2016 - New England College of Optometry
... different visual stimuli at different times of day, to determine if there is a phasedependency to their efficacy at inhibiting growth, and then to determine how the rhythm parameters in choroidal thickness and axial length are differentially altered. I am also looking at the possibility that there i ...
... different visual stimuli at different times of day, to determine if there is a phasedependency to their efficacy at inhibiting growth, and then to determine how the rhythm parameters in choroidal thickness and axial length are differentially altered. I am also looking at the possibility that there i ...
Module - Mount Sinai Hospital
... optic nerve optic fissure When optic nerve and/or retina is involved, vision is affected. Isolated iris colobomas may not affect visual acuity. Decreased visual acuity, photophobia, field loss often result from colobomas, depending on area that failed to develop. Congenital cataracts Wright ...
... optic nerve optic fissure When optic nerve and/or retina is involved, vision is affected. Isolated iris colobomas may not affect visual acuity. Decreased visual acuity, photophobia, field loss often result from colobomas, depending on area that failed to develop. Congenital cataracts Wright ...
MINISTRY OF HEALTH OF THE REPUBLIC OF UZBEKISTAN
... •takes part in the regeneration of rhodopsin and cone opsin,the photoreceptor visual pigments recycling vitamin A; •melanin granules absorb scattered light. The retina: •Is a highly complex structure divided into ten separate layers comprising photoreceptors (rods and cones) and neurones,some of whi ...
... •takes part in the regeneration of rhodopsin and cone opsin,the photoreceptor visual pigments recycling vitamin A; •melanin granules absorb scattered light. The retina: •Is a highly complex structure divided into ten separate layers comprising photoreceptors (rods and cones) and neurones,some of whi ...
Surface Area of Pyramid and Cone
... Surface Areas of Pyramids Pyramid – a polyhedron in which one face (the base) can be any polygon and the other faces (the lateral faces) are triangles that meet at a common vertex (called the vertex of the pyramid). Altitude – altitude of a pyramid the perpendicular segment from the vertex to the pl ...
... Surface Areas of Pyramids Pyramid – a polyhedron in which one face (the base) can be any polygon and the other faces (the lateral faces) are triangles that meet at a common vertex (called the vertex of the pyramid). Altitude – altitude of a pyramid the perpendicular segment from the vertex to the pl ...
Document
... to think of it is as something like a computer that receives inputs from 100 million photodetectors that are sampling the pattern of light and dark in the image formed by the eye’s optical system. The retina processes the information it receives and transmits it to the brain via the million or so ne ...
... to think of it is as something like a computer that receives inputs from 100 million photodetectors that are sampling the pattern of light and dark in the image formed by the eye’s optical system. The retina processes the information it receives and transmits it to the brain via the million or so ne ...
ANATOMY OF INNER EAR
... • Associated with hair cells • Inner phalangeal cells & border cells enclose inner hair cells • Deiters’ cells enclose outer hair cells & send phalangeal processes to the adjacent cells • Hensen’s cells & Claudius’ cells are present on the outer edge of basilar membrane ...
... • Associated with hair cells • Inner phalangeal cells & border cells enclose inner hair cells • Deiters’ cells enclose outer hair cells & send phalangeal processes to the adjacent cells • Hensen’s cells & Claudius’ cells are present on the outer edge of basilar membrane ...
Notes: Surface Area of Pyramids and Cones
... The vertex of a pyramid is the point opposite the base of the pyramid. The base of a regular pyramid is a regular polygon, and the lateral faces are congruent isosceles triangles. The slant height of a regular pyramid is the distance from the vertex to the midpoint of an edge of the base. The altitu ...
... The vertex of a pyramid is the point opposite the base of the pyramid. The base of a regular pyramid is a regular polygon, and the lateral faces are congruent isosceles triangles. The slant height of a regular pyramid is the distance from the vertex to the midpoint of an edge of the base. The altitu ...
Gene Therapy and Animal Models for Retinal Disease
... Retinitis pigmentosa (RP) represents a group of inherited retinal disorders that affect approximately 1 in 3,000 individuals worldwide. RP is characterized by early-onset night blindness, which is followed by central vision loss. Patients with autosomal recessive (AR) disease often begin having symp ...
... Retinitis pigmentosa (RP) represents a group of inherited retinal disorders that affect approximately 1 in 3,000 individuals worldwide. RP is characterized by early-onset night blindness, which is followed by central vision loss. Patients with autosomal recessive (AR) disease often begin having symp ...
the special senses
... Lecture Material is adapted from © 2013 Pearson Education, Inc. Human Anatomy and Physiology ...
... Lecture Material is adapted from © 2013 Pearson Education, Inc. Human Anatomy and Physiology ...
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.