PD Lecture 1999 - University of Pittsburgh
... – Cysts tend to be uniformly distributed; look closely are regions where solid tissue obliterates cysts at one end of lesion – Pagetoid spread of melanocytes ...
... – Cysts tend to be uniformly distributed; look closely are regions where solid tissue obliterates cysts at one end of lesion – Pagetoid spread of melanocytes ...
Chapter 7 Body Systems
... • Develops when an adequate stimulus acts on a receptor; is a graded response • When a threshold is reached, an action potential in the sensory neuron’s axon is triggered • Impulses travel over sensory pathways to the brain and spinal cord, where either they are interpreted as a particular sensation ...
... • Develops when an adequate stimulus acts on a receptor; is a graded response • When a threshold is reached, an action potential in the sensory neuron’s axon is triggered • Impulses travel over sensory pathways to the brain and spinal cord, where either they are interpreted as a particular sensation ...
MCQs 3.25MB 2017-03
... b. more plus lens will be needed if the patient is on MAO inhibitors c. more plus lens is needed in a patient who accommodates excessively d. more minus lens is required in poorly controlled diabetes e. hypermetropic shift occurs in nuclear sclerosis. ...
... b. more plus lens will be needed if the patient is on MAO inhibitors c. more plus lens is needed in a patient who accommodates excessively d. more minus lens is required in poorly controlled diabetes e. hypermetropic shift occurs in nuclear sclerosis. ...
Defects in corneal endothelium in TGF(alpha
... thicker and contained more cell layers, but still lacked a basement membrane structure (Fig. 5C). The structure of the corneal stroma also appeared to be more normal. Our data suggest that proper differentiation and maturation of corneal epithelial and stromal cell may be dependent on the presence o ...
... thicker and contained more cell layers, but still lacked a basement membrane structure (Fig. 5C). The structure of the corneal stroma also appeared to be more normal. Our data suggest that proper differentiation and maturation of corneal epithelial and stromal cell may be dependent on the presence o ...
Commentary Sympathetic ophthalmia risk following vitrectomy
... to be an underestimate owing to underreporting or errors in diagnosis but there may also be an underestimate of the number of retinal surgical procedures performed. Finished consultant episodes do not represent the number of patients undergoing certain operations, and as a patient may have more than ...
... to be an underestimate owing to underreporting or errors in diagnosis but there may also be an underestimate of the number of retinal surgical procedures performed. Finished consultant episodes do not represent the number of patients undergoing certain operations, and as a patient may have more than ...
Glare
... excessive blinking, ocular spasms and even pain is referred to as ‘discomfort glare’. Conventionally, the two types of glare have been regarded as different results of the same phenomenon; the eye cannot simultaneously process extreme differences in intensity levels. There is thus no unique link bet ...
... excessive blinking, ocular spasms and even pain is referred to as ‘discomfort glare’. Conventionally, the two types of glare have been regarded as different results of the same phenomenon; the eye cannot simultaneously process extreme differences in intensity levels. There is thus no unique link bet ...
Quantitative reflection spectroscopy at the human ocular fundus
... caucasians as well as patients suffering from macular holes, age-related macular degeneration (AMD), juvenile macular degeneration and high myopia were measured by imaging fundus reflectometry. The technique is described in detail elsewhere (Hammer 1997). In principle, the light of the xenon flash o ...
... caucasians as well as patients suffering from macular holes, age-related macular degeneration (AMD), juvenile macular degeneration and high myopia were measured by imaging fundus reflectometry. The technique is described in detail elsewhere (Hammer 1997). In principle, the light of the xenon flash o ...
Novel ophthalmic imaging
... Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA; 3Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA; 4Center for Neurosci ...
... Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA; 3Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA; 4Center for Neurosci ...
PDF
... 3. Eye rudiments at the age of 13-5 and 14-5 days The experiments on the transplantations of eye rudiments without surrounding mesenchyme from older embryos (13-5 and 14-5 days) were unsuccessful. At the same time as becoming pigmented, the external layer of the eye rudiment gets thin and sticky. Th ...
... 3. Eye rudiments at the age of 13-5 and 14-5 days The experiments on the transplantations of eye rudiments without surrounding mesenchyme from older embryos (13-5 and 14-5 days) were unsuccessful. At the same time as becoming pigmented, the external layer of the eye rudiment gets thin and sticky. Th ...
zeaxantina - A Fórmula
... of these degenerative eye diseases. Further research is necessary to confirm these observations. ...
... of these degenerative eye diseases. Further research is necessary to confirm these observations. ...
Paranasal Sinus Anatomy and Function January 2002
... In the late teen years the sinus reaches it's full size with a volume of 7.5 ml (23x20x17mm). Pneumatization of this sinus, like that of the frontal sinus, is very variable. Generally these are bilateral structures located at the posteriosuperior aspect of the nasal cavity. Pneumatization can extend ...
... In the late teen years the sinus reaches it's full size with a volume of 7.5 ml (23x20x17mm). Pneumatization of this sinus, like that of the frontal sinus, is very variable. Generally these are bilateral structures located at the posteriosuperior aspect of the nasal cavity. Pneumatization can extend ...
orbits
... increases its diameter (dilates the pupil) The sympathe:c responses usually occur immediately, yet it may take up to 20 min for the pupil to dilate in response to low ligh:ng The pupillary reflex pathway begins with the photosensi:ve re:na ganglion cells, which convey informa:on via the op:c nerv ...
... increases its diameter (dilates the pupil) The sympathe:c responses usually occur immediately, yet it may take up to 20 min for the pupil to dilate in response to low ligh:ng The pupillary reflex pathway begins with the photosensi:ve re:na ganglion cells, which convey informa:on via the op:c nerv ...
Radiological anatomy of frontal sinus (PDF Available)
... causes terminal recess to form. Frontal sinus drains directly into middle meatus as shown in this figure ...
... causes terminal recess to form. Frontal sinus drains directly into middle meatus as shown in this figure ...
ON THE DEVELOPMENT OF THE TUSSER, ANTHERAEA PERNYI
... compared to the primitive groove of higher vertebrate animals as it becomes a differentiation center of the later development. From the time of invagination the mere uniformly structured cell aggregation of the ventral plate gives rise at the floor of the groove to the polygonal shaped cell mass and ...
... compared to the primitive groove of higher vertebrate animals as it becomes a differentiation center of the later development. From the time of invagination the mere uniformly structured cell aggregation of the ventral plate gives rise at the floor of the groove to the polygonal shaped cell mass and ...
Vitrectomy prevents retinal hypoxia in branch retinal vein occlusion.
... fellow eyes before and after branch retinal vein occlusion. In five additional cats the preretinal oxygen tension was measured in normal eyes before and after branch retinal vein occlusion. The cats (2-4 kg, and of either sex) were anesthetized with intramuscular ketamine hydrochloride (20-30 mg/kg) ...
... fellow eyes before and after branch retinal vein occlusion. In five additional cats the preretinal oxygen tension was measured in normal eyes before and after branch retinal vein occlusion. The cats (2-4 kg, and of either sex) were anesthetized with intramuscular ketamine hydrochloride (20-30 mg/kg) ...
Regenerative Approaches as Alternatives to Donor Allografting for Restoration of Corneal Function
... Clearly, the interactions between the growth factor-modified polymer and the cells are complex and require further study but have significant potential to alter epithelization of KPro’s materials. Underlying surface modifications also appear to play a role in the extent of cell coverage, as well as ...
... Clearly, the interactions between the growth factor-modified polymer and the cells are complex and require further study but have significant potential to alter epithelization of KPro’s materials. Underlying surface modifications also appear to play a role in the extent of cell coverage, as well as ...
The Histology of the Pulp
... Recognize, Capture Foreign Ag Non-Phagocytic Increased in Carious Teeth Class II MHC Positive ...
... Recognize, Capture Foreign Ag Non-Phagocytic Increased in Carious Teeth Class II MHC Positive ...
Optical properties of the mouse eye
... Knowledge of the optical aberrations of the mouse eye is important not only for understanding the visual capabilities of the mouse, but also because correcting these aberrations can improve the quality of in vivo images of the mouse retina. In vivo imaging offers the advantage over post mortem hist ...
... Knowledge of the optical aberrations of the mouse eye is important not only for understanding the visual capabilities of the mouse, but also because correcting these aberrations can improve the quality of in vivo images of the mouse retina. In vivo imaging offers the advantage over post mortem hist ...
The ethmoid bone: clinical imaging anatomy from an embryological
... Fig. 4: Ascending and descending portions of the middle turbinate, lateral aspect of nasal cavity, and coronal section. Ethmoturbinal is divided into lamina basilaris (red dotted line) and lamina recurvata (blue line). The lamina basilaris forms part of the lateral wall attachment. The lamina recur ...
... Fig. 4: Ascending and descending portions of the middle turbinate, lateral aspect of nasal cavity, and coronal section. Ethmoturbinal is divided into lamina basilaris (red dotted line) and lamina recurvata (blue line). The lamina basilaris forms part of the lateral wall attachment. The lamina recur ...
Sensory & Motor Mechanisms
... EXPERIMENT Insects taste using gustatory sensilla (hairs) on their feet and mouthparts. Each sensillum contains four chemoreceptors with dendrites that extend to a pore at the tip of the sensillum. To study the sensitivity of each chemoreceptor, researchers immobilized a blowfly (Phormia regina) by ...
... EXPERIMENT Insects taste using gustatory sensilla (hairs) on their feet and mouthparts. Each sensillum contains four chemoreceptors with dendrites that extend to a pore at the tip of the sensillum. To study the sensitivity of each chemoreceptor, researchers immobilized a blowfly (Phormia regina) by ...
heent - Labmongers2
... continue to grow, may push iris forward causing narrow-angle glaucoma. Ophthalmoscopic exam reveals: fundi lose shine and light reflections; arteries look narrowed, paler, straighter, and less brilliant; may see vitreous floaters and serious conditions such as macular degeneration, glaucoma, retinal ...
... continue to grow, may push iris forward causing narrow-angle glaucoma. Ophthalmoscopic exam reveals: fundi lose shine and light reflections; arteries look narrowed, paler, straighter, and less brilliant; may see vitreous floaters and serious conditions such as macular degeneration, glaucoma, retinal ...
Vestibular Pathways
... The fastigial nuclei are the medialmost of the deep cerebellar nuclei located in the subcortical white matter of the cerebellum in the roof of the fourth ventricle. These nuclei have reciprocal connections with the vestibular complex through the inferior cerebellar ...
... The fastigial nuclei are the medialmost of the deep cerebellar nuclei located in the subcortical white matter of the cerebellum in the roof of the fourth ventricle. These nuclei have reciprocal connections with the vestibular complex through the inferior cerebellar ...
Vitreoretinal / Ocular Trauma - Sight Loss and Vision Priority Setting
... partners, relatives and carers and eye health professionals. The survey submissions relating to vitreoretinal/ocular trauma were checked and formatted into questions. Where there were duplicates, or very similar submissions, these were combined. The questions below are defined as uncertain because t ...
... partners, relatives and carers and eye health professionals. The survey submissions relating to vitreoretinal/ocular trauma were checked and formatted into questions. Where there were duplicates, or very similar submissions, these were combined. The questions below are defined as uncertain because t ...
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.