Eye
... You will be presented with clinical images or illustrations. Answers will be provided in the following slide. ...
... You will be presented with clinical images or illustrations. Answers will be provided in the following slide. ...
Combined Hamartoma of the Retina and Retinal Pigment Epithelium
... retina and RPE were initially described by Gass3 as: (1) a mildly raised, black or dark grey lesion affecting the retina, RPE and surrounding vitreous; (2) expanding toward the periphery; (3) fusing indiscriminately with neighboring RPE; (4) encapsulated by dense grey-white retinal and preretinal ti ...
... retina and RPE were initially described by Gass3 as: (1) a mildly raised, black or dark grey lesion affecting the retina, RPE and surrounding vitreous; (2) expanding toward the periphery; (3) fusing indiscriminately with neighboring RPE; (4) encapsulated by dense grey-white retinal and preretinal ti ...
Why Wear Sunglasses?
... There is little evidence that the lens is damaged by UV light, above and beyond other influences such as diabetes or smoking. There is clear laboratory evidence that UV light can be used to promote cataracts in animals, but epidemiological studies in humans have contradicted each other. These studie ...
... There is little evidence that the lens is damaged by UV light, above and beyond other influences such as diabetes or smoking. There is clear laboratory evidence that UV light can be used to promote cataracts in animals, but epidemiological studies in humans have contradicted each other. These studie ...
6:7 Special Senses
... 3. Tough coating, helps maintain shape of eye 4. Muscles responsible for moving eye attached to sclera = extrinsic muscles ...
... 3. Tough coating, helps maintain shape of eye 4. Muscles responsible for moving eye attached to sclera = extrinsic muscles ...
Nervous System Assignment Section 8.1 1. The 3 specific functions
... The axon can branch into many endings that are known as ________axon terminals___________________________. The endings come close to other neurons at an area called a ________synapse___________. The two neurons do not touch each other, but instead are separated by a gap called the _________synaptic ...
... The axon can branch into many endings that are known as ________axon terminals___________________________. The endings come close to other neurons at an area called a ________synapse___________. The two neurons do not touch each other, but instead are separated by a gap called the _________synaptic ...
Document
... • The inner tunic consists of the retina, which contains photoreceptors; the inner tunic covers the back side of the eye to the ciliary body. – Two kinds of photoreceptors comprise the visual receptors; elongated rods and blunt-shaped cones. » Rods are more sensitive to light and function in dim lig ...
... • The inner tunic consists of the retina, which contains photoreceptors; the inner tunic covers the back side of the eye to the ciliary body. – Two kinds of photoreceptors comprise the visual receptors; elongated rods and blunt-shaped cones. » Rods are more sensitive to light and function in dim lig ...
Workbook 6 - Macmillan Caribbean
... The light-sensitive layer that covers the inside surface of the back of the eye.____________ The black aperture (hole) at the centre of the iris through which light passes into the eye. ____________ The nerve which carries information from the eye to the brain. ____________ The transparent disc whic ...
... The light-sensitive layer that covers the inside surface of the back of the eye.____________ The black aperture (hole) at the centre of the iris through which light passes into the eye. ____________ The nerve which carries information from the eye to the brain. ____________ The transparent disc whic ...
Low Vi - Thomas H. Collison Ltd
... retina. Conditions such as glaucoma, diabetes and macular degeneration cause damage to the retinal cells. This causes areas of blank vision within the field of vision. Sometimes these areas only occur in one eye and the binocular effect overcomes the loss of field. Unfortunately in many cases this i ...
... retina. Conditions such as glaucoma, diabetes and macular degeneration cause damage to the retinal cells. This causes areas of blank vision within the field of vision. Sometimes these areas only occur in one eye and the binocular effect overcomes the loss of field. Unfortunately in many cases this i ...
Vision Lab Handout
... 1. ___________________________ is the sharpness of the perceived visual image and is often evaluated in clinical situations with the _____________________ eye test. 2. A person with 20-100 vision can see an object at ____________________feet where a normal person can see that object at _____________ ...
... 1. ___________________________ is the sharpness of the perceived visual image and is often evaluated in clinical situations with the _____________________ eye test. 2. A person with 20-100 vision can see an object at ____________________feet where a normal person can see that object at _____________ ...
Test for visual Acuity, Color vision , and Visual Field
... Trichromatic Theory (Young Helmholtz theory) There are 3 types of cones; each is containing one of three pigments according to their sensitivity to a certain light wavelength: S S cones most sensitive to short wavelength (peak cones most sensitive absorption at 420nm→perception of blue colo ...
... Trichromatic Theory (Young Helmholtz theory) There are 3 types of cones; each is containing one of three pigments according to their sensitivity to a certain light wavelength: S S cones most sensitive to short wavelength (peak cones most sensitive absorption at 420nm→perception of blue colo ...
Retinal detachment surgery
... performed. If the eyes response is good, vision will be recuperated progressively during the following 6 to 12 months. In the cases with intraocular gas injection, the patient the patient must perform a postural treatment on the days following the surgery. With the current surgical techniques, appr ...
... performed. If the eyes response is good, vision will be recuperated progressively during the following 6 to 12 months. In the cases with intraocular gas injection, the patient the patient must perform a postural treatment on the days following the surgery. With the current surgical techniques, appr ...
The current Status of Stem cells in eye care
... Adult SCs are rare cells found in various organs or tissues and have a limited ability to differentiate into cells with specific functions. They are older and less powerful than other types. Although these stem cells do not require the use or destruction of a fertilized egg or extensive manipulation ...
... Adult SCs are rare cells found in various organs or tissues and have a limited ability to differentiate into cells with specific functions. They are older and less powerful than other types. Although these stem cells do not require the use or destruction of a fertilized egg or extensive manipulation ...
I./3. : Ear: Anatomy and Physiology
... membrane. This means the voltage dependent contraction and elongation of the cell, which develop at the incoming sound’s frequency. Since outer hair cells cilia are embedded in the tectorial membrane their movements supply positive energy feedback against the system’s high incapacity, viscous dampin ...
... membrane. This means the voltage dependent contraction and elongation of the cell, which develop at the incoming sound’s frequency. Since outer hair cells cilia are embedded in the tectorial membrane their movements supply positive energy feedback against the system’s high incapacity, viscous dampin ...
The Senses
... Presbyopia: old-sightedness which is usually farsighted; acquired ~ 40 years Astigmatism: irregular curvature of cornea or lens Color-blindness: inherited inability to see certain colors due to missing cones; males affected more often (sexlinkage) Cataracts: clouding of lens; may cause blind ...
... Presbyopia: old-sightedness which is usually farsighted; acquired ~ 40 years Astigmatism: irregular curvature of cornea or lens Color-blindness: inherited inability to see certain colors due to missing cones; males affected more often (sexlinkage) Cataracts: clouding of lens; may cause blind ...
VISUAL FIELD DEFECTS: TO INFINITY AND BEYOND
... a) Orbital section extends from the globe to the optic foramen b) Intra-canalicular portion extends through the optic canal c) Intra-cranial section extends from the posterior optic canal to the anterior chiasm C. Chiasmal 1. Optic nerves converge over the sella turcica to form the chiasm 2. Nasal r ...
... a) Orbital section extends from the globe to the optic foramen b) Intra-canalicular portion extends through the optic canal c) Intra-cranial section extends from the posterior optic canal to the anterior chiasm C. Chiasmal 1. Optic nerves converge over the sella turcica to form the chiasm 2. Nasal r ...
Cytoskeletal Involvement in the Regulation of Aqueous Humor Outflow
... cytoplasmic traffic of vesicles and organelles. Their main molecular constituent is the heterodimeric protein tubulin (␣ and  subunits). In addition, associated proteins bind to microtubules and can affect their stability and potentially attach them to other cellular structures, including other cyt ...
... cytoplasmic traffic of vesicles and organelles. Their main molecular constituent is the heterodimeric protein tubulin (␣ and  subunits). In addition, associated proteins bind to microtubules and can affect their stability and potentially attach them to other cellular structures, including other cyt ...
lecture2
... Neurophysiology & Anatomy: Structure and function of nervous system. What are the neural processes underlying behavior? ...
... Neurophysiology & Anatomy: Structure and function of nervous system. What are the neural processes underlying behavior? ...
Basic Anatomy and Physiology of the Eye
... The blood supply of the globe is derived from three sources: the central retinal artery, the anterior ciliary arteries and the posterior ciliary arteries. All these are derived from the ophthalmic artery, which is a branch of the internal carotid. The central retinal artery runs in the optic nerve t ...
... The blood supply of the globe is derived from three sources: the central retinal artery, the anterior ciliary arteries and the posterior ciliary arteries. All these are derived from the ophthalmic artery, which is a branch of the internal carotid. The central retinal artery runs in the optic nerve t ...
Bio 450 - Lab 3 - AP Propagation
... Several of the genes encoding photoreceptor proteins used by cone cells are located on the X chromosome. These genes occasionally mutate, with the result that the photoreceptors they produce may be either less sensitive than normal or completely non-functional. These mutations tend to be recessive, ...
... Several of the genes encoding photoreceptor proteins used by cone cells are located on the X chromosome. These genes occasionally mutate, with the result that the photoreceptors they produce may be either less sensitive than normal or completely non-functional. These mutations tend to be recessive, ...
Special Senses
... receptors for these senses are ciliated cells called hair cells. Movement of the cilia cause the hair cells to produce nerve impulses which are sent to the brain via the eighth cranial nerve. ...
... receptors for these senses are ciliated cells called hair cells. Movement of the cilia cause the hair cells to produce nerve impulses which are sent to the brain via the eighth cranial nerve. ...
Module - Mount Sinai Hospital
... much of the available light as possible to see (2). The pupil is only an opening in the iris; it looks black because the eye is dark inside. The whole front of the eye, including the pupil, is covered with a protective layer called the cornea. Color ...
... much of the available light as possible to see (2). The pupil is only an opening in the iris; it looks black because the eye is dark inside. The whole front of the eye, including the pupil, is covered with a protective layer called the cornea. Color ...
special senses
... ○ pigmented layer ■ absorbs light and prevents light from scatering inside the eye. ■ acts as phagocytes to remove dead or damaged receptor cells ■ Stores vitamin A ○ neural layer - transparent inner layer containing photoreceptors - rods and cones ...
... ○ pigmented layer ■ absorbs light and prevents light from scatering inside the eye. ■ acts as phagocytes to remove dead or damaged receptor cells ■ Stores vitamin A ○ neural layer - transparent inner layer containing photoreceptors - rods and cones ...
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.