Think of it as a fluid- filled sac floating in a fluid
... to linear acceleration, which is straight-line changes in speed and direction (velocity). It is perceived in the VESTIBULE. o Maculae of utricles is horizontal and detect horizontal movement…forward, backward,side to side o Maculae of saccule is verticle and detects up and down movement. HOW DOES TH ...
... to linear acceleration, which is straight-line changes in speed and direction (velocity). It is perceived in the VESTIBULE. o Maculae of utricles is horizontal and detect horizontal movement…forward, backward,side to side o Maculae of saccule is verticle and detects up and down movement. HOW DOES TH ...
ANATOMY OF THE OUTER EAR EAR PINNA is the outer
... to linear acceleration, which is straight-line changes in speed and direction (velocity). It is perceived in the VESTIBULE. o Maculae of utricles is horizontal and detect horizontal movement…forward, backward,side to side o Maculae of saccule is verticle and detects up and down movement. HOW DOES TH ...
... to linear acceleration, which is straight-line changes in speed and direction (velocity). It is perceived in the VESTIBULE. o Maculae of utricles is horizontal and detect horizontal movement…forward, backward,side to side o Maculae of saccule is verticle and detects up and down movement. HOW DOES TH ...
Changes in retinal aquaporin-9 (AQP9) expression in glaucoma
... was up-regulated after transient brain ischaemia [21]. Because AQP4 expression is polarized in brain astrocytes when in contact with endothelial cells and neurons [22,23], it was no surprise that AQP4-null mice had better retinal structure and larger cell numbers than the wild-type mice after ischae ...
... was up-regulated after transient brain ischaemia [21]. Because AQP4 expression is polarized in brain astrocytes when in contact with endothelial cells and neurons [22,23], it was no surprise that AQP4-null mice had better retinal structure and larger cell numbers than the wild-type mice after ischae ...
pupil and accomodation abnormalities
... •To correctly search for the presence of a RAPD it is necessary to begin with both pupils in the dark. Each pupil is then rapidly illuminated in an alternating way (for maximum 3 seconds) passing above the nose. • A monolateral lesion of the optic nerve is practically always associated to a relativ ...
... •To correctly search for the presence of a RAPD it is necessary to begin with both pupils in the dark. Each pupil is then rapidly illuminated in an alternating way (for maximum 3 seconds) passing above the nose. • A monolateral lesion of the optic nerve is practically always associated to a relativ ...
Protective Effects of Morus albaLeaves Extract on Ocular Functions
... and II diabetes and cataract in patients (5, 6). Although there is no distinctive relationship between lens cholesterol content and cataract (7), the possibility is that sterol composition of the lens was changed in cataract due to oxidation (8). Neurotransmitters play a key role in the neuro-sensor ...
... and II diabetes and cataract in patients (5, 6). Although there is no distinctive relationship between lens cholesterol content and cataract (7), the possibility is that sterol composition of the lens was changed in cataract due to oxidation (8). Neurotransmitters play a key role in the neuro-sensor ...
Distance Learning Program Pig Eye Dissection Middle School/ High School
... damage to the optic nerve. It was once thought that high intraocular pressure (IOP) was the main cause of this optic nerve damage. Although IOP is clearly a risk factor, we now know that other factors must also be involved because even people with "normal" IOP can experience vision loss from glaucom ...
... damage to the optic nerve. It was once thought that high intraocular pressure (IOP) was the main cause of this optic nerve damage. Although IOP is clearly a risk factor, we now know that other factors must also be involved because even people with "normal" IOP can experience vision loss from glaucom ...
Precise long non-coding RNA modulation in visual maintenance
... lncRNAs referring to gene ontology (GO), biological process annotations and genomic adjacency. The functions of lncRNAs mainly involve organ or tissue development, especially eye and neuron development.2–4 This research leads us to focus on the importance of lncRNAs in normal eye development, the fo ...
... lncRNAs referring to gene ontology (GO), biological process annotations and genomic adjacency. The functions of lncRNAs mainly involve organ or tissue development, especially eye and neuron development.2–4 This research leads us to focus on the importance of lncRNAs in normal eye development, the fo ...
Ectodermal Derivtives2008-11-18 02:441.6 MB
... DegeneratesFate and of Notochord disappears as the bodies of the vertebrae develop The part that lies between the vertebral bodies persists as the nucleus pulposus of each intervertebral disc Remnants of notochordal tissue give rise to tumors called Chordomas ...
... DegeneratesFate and of Notochord disappears as the bodies of the vertebrae develop The part that lies between the vertebral bodies persists as the nucleus pulposus of each intervertebral disc Remnants of notochordal tissue give rise to tumors called Chordomas ...
Ectodermal Derivtives
... Disturbance of neurulation may result in severe abnormalities of the brain and the spinal cord Most defects are the result of non-closure or defective closure of the neural tube: • In the brain region (e.g. anencephaly) • In the spinal cord regions (e.g. spina ...
... Disturbance of neurulation may result in severe abnormalities of the brain and the spinal cord Most defects are the result of non-closure or defective closure of the neural tube: • In the brain region (e.g. anencephaly) • In the spinal cord regions (e.g. spina ...
Descemet Membrane Endothelial Keratoplasty: Update on
... [2, 8]. FECD is the most common endothelial dystrophy (the others have the same indications for surgery but, from the perspective of statistical incidence, are almost insignificant) and is usually seen beyond the fifth decade of life, although not all cases are in the elderly; Biswas et al. reported ...
... [2, 8]. FECD is the most common endothelial dystrophy (the others have the same indications for surgery but, from the perspective of statistical incidence, are almost insignificant) and is usually seen beyond the fifth decade of life, although not all cases are in the elderly; Biswas et al. reported ...
August 2009 - Retina New Zealand
... Alhazen carried the theory of vision to a sufficiently advanced level to have been able to introduce the use of lens. But it was much later that it was actually achieved. The first recognition of the possibility seems to have come from Roger Bacon who discussed the use of segments of spheres and sho ...
... Alhazen carried the theory of vision to a sufficiently advanced level to have been able to introduce the use of lens. But it was much later that it was actually achieved. The first recognition of the possibility seems to have come from Roger Bacon who discussed the use of segments of spheres and sho ...
ANATOMY OF THE STOMACH AND DUODENUM
... cells or in groups of two or three in the oxyntic gland neck or isthmus. Mucous neck cells differ from their surface counterparts in their synthesis of acidic, sulfated mucus rather than the neutral mucus. Additionally, mucous neck cells have basal nuclei and larger mucous granules around the nucleu ...
... cells or in groups of two or three in the oxyntic gland neck or isthmus. Mucous neck cells differ from their surface counterparts in their synthesis of acidic, sulfated mucus rather than the neutral mucus. Additionally, mucous neck cells have basal nuclei and larger mucous granules around the nucleu ...
Eye & Orbit
... superior/inferior rectus pair and inferior/superior oblique pair. The center part of the H will test the medial and lateral muscles. •Obliques are unique and involve adduction of globe prior to elevation and depression ...
... superior/inferior rectus pair and inferior/superior oblique pair. The center part of the H will test the medial and lateral muscles. •Obliques are unique and involve adduction of globe prior to elevation and depression ...
Visual Loss of Uncertain Origin: Diagnostic Strategies
... with the light source held below the level of the line of sight, elevated at about a 45° angle (so that the patient can see over and beyond the light source). Initially both eyes are illuminated from two separate distances, during which one should note whether the two pupils are equal in size and wh ...
... with the light source held below the level of the line of sight, elevated at about a 45° angle (so that the patient can see over and beyond the light source). Initially both eyes are illuminated from two separate distances, during which one should note whether the two pupils are equal in size and wh ...
research day - Faculty of Medicine
... way, they show promise as a chemical visual prosthesis to recreate visual function where photoreceptors are damaged beyond repair but the inner retina is still intact. In this study, we aim to determine the efficacy of these photoswitch proteins in restoring photosensitivity and vision in a rat mode ...
... way, they show promise as a chemical visual prosthesis to recreate visual function where photoreceptors are damaged beyond repair but the inner retina is still intact. In this study, we aim to determine the efficacy of these photoswitch proteins in restoring photosensitivity and vision in a rat mode ...
Branch Retinal Artery Occlusion: A Complication of Iron
... Branch Retinal Artery Occlusion: A Complication of Iron-Deficiency Anemia in a Young Adult with a Rectal Carcinoid. Tohoku J. Exp. Med., 2004, 203 (2), 141-144 ── We report a case of branch retinal artery occlusion (BRAO) in a patient with iron-deficiency anemia. Various ophthalmological and laborat ...
... Branch Retinal Artery Occlusion: A Complication of Iron-Deficiency Anemia in a Young Adult with a Rectal Carcinoid. Tohoku J. Exp. Med., 2004, 203 (2), 141-144 ── We report a case of branch retinal artery occlusion (BRAO) in a patient with iron-deficiency anemia. Various ophthalmological and laborat ...
ISCEV standard for clinical electro-oculography (2010
... There is a difference in electrical potential between the front and back of the eye, sometimes called the corneo-fundal potential or standing potential. This potential is mainly derived from the retinal pigment epithelium (RPE), and it changes in response to background levels of retinal illumination ...
... There is a difference in electrical potential between the front and back of the eye, sometimes called the corneo-fundal potential or standing potential. This potential is mainly derived from the retinal pigment epithelium (RPE), and it changes in response to background levels of retinal illumination ...
Altered mechanobiology of SchlemmTs canal endothelial cells in
... stiffer SC cells. To investigate this possibility, we measured the stiffness of SC cells isolated from normal and glaucomatous human donors (Materials and Methods) using atomic force microscopy (AFM) using both sharp tips (20-nm tip radius) and rounded tips (4.5 μm and 10 μm) (10). In other cellular ...
... stiffer SC cells. To investigate this possibility, we measured the stiffness of SC cells isolated from normal and glaucomatous human donors (Materials and Methods) using atomic force microscopy (AFM) using both sharp tips (20-nm tip radius) and rounded tips (4.5 μm and 10 μm) (10). In other cellular ...
Fishes with Eye Shine: Functional Morphology of Guanine Type
... may occur as part of the retinornotor responses to light and dark adaptation. The choroidal tapetum is located in the vitread region of the choroid, and in most cases the c ~ y s t aarrangement l is such that it forms a specular reflector. In many retinas with a choroidal tapeturn, the retinal pigme ...
... may occur as part of the retinornotor responses to light and dark adaptation. The choroidal tapetum is located in the vitread region of the choroid, and in most cases the c ~ y s t aarrangement l is such that it forms a specular reflector. In many retinas with a choroidal tapeturn, the retinal pigme ...
Ocular abnormalities in the myopathic hamster (UM-X7.1
... • whether intraocular pressures were normal, but changes in the sclera, cornea, and retina might be secondary to glaucoma. Infantile glaucoma has occasionally been observed in patients with Marfan's syndrome and Weill-Marchesani syndrome.12 At present, the exact nature of the abnormalities and the s ...
... • whether intraocular pressures were normal, but changes in the sclera, cornea, and retina might be secondary to glaucoma. Infantile glaucoma has occasionally been observed in patients with Marfan's syndrome and Weill-Marchesani syndrome.12 At present, the exact nature of the abnormalities and the s ...
Innovative Techniques and Technology
... analysis of the number of corneal and conjunctival cells, using antibodies against K3 and K19, respectively, as quality control determinants. All the corneal epithelial cultures used for grafting showed expression levels of the corneal marker K3 ranging between 60% and 90% and the conjunctival marke ...
... analysis of the number of corneal and conjunctival cells, using antibodies against K3 and K19, respectively, as quality control determinants. All the corneal epithelial cultures used for grafting showed expression levels of the corneal marker K3 ranging between 60% and 90% and the conjunctival marke ...
The Visceral Nervous System
... arrectores pilorum and sweat glands of head, neck, trunk and limbs The fibers from their networks around blood vessels passing to visceral end organs Terminate directly in certain organs ...
... arrectores pilorum and sweat glands of head, neck, trunk and limbs The fibers from their networks around blood vessels passing to visceral end organs Terminate directly in certain organs ...
sample
... c. orbital tunic b. nervous tunic d. vascular tunic ANS: A The eye is the sensory receptor of the visual system that transduces light from the environment into electrical impulses, which the optic nerve then transmits to the brain to be interpreted as vision. The fibrous tunic is the outer coat of t ...
... c. orbital tunic b. nervous tunic d. vascular tunic ANS: A The eye is the sensory receptor of the visual system that transduces light from the environment into electrical impulses, which the optic nerve then transmits to the brain to be interpreted as vision. The fibrous tunic is the outer coat of t ...
Endoscopy for Vitreoretinal Surgeons
... of the fragile glass fiber scopes. Pearls for use. Once the surgeon is in the OR, it might be advisable to start with using the endoscope as a light pipe and noting the endoscopic image on the display screen through- ...
... of the fragile glass fiber scopes. Pearls for use. Once the surgeon is in the OR, it might be advisable to start with using the endoscope as a light pipe and noting the endoscopic image on the display screen through- ...
Space: The Whole Whizz-Bang
... this rule are owls, which have two forward-facing eyes and incredibly powerful 3D vision. This makes them deadly night-time hunters, and the terror of every mouse, vole and scampering rodent in the land. Once they lock their wide-eyed gaze upon you, there’s nowhere to run and nowhere to hide. ...
... this rule are owls, which have two forward-facing eyes and incredibly powerful 3D vision. This makes them deadly night-time hunters, and the terror of every mouse, vole and scampering rodent in the land. Once they lock their wide-eyed gaze upon you, there’s nowhere to run and nowhere to hide. ...
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.