The optic nerve (CN II) arises from axons of ganglion cells of the
... • fibers from the temporal half of the left eye and nasal half of the right eye The optic nerve (CN II) arises from axons of ganglion cells of the retina, which converge at the optic disc. The optic nerve leaves the orbital cavity by passing through the optic foramen (also called optic canal) of the ...
... • fibers from the temporal half of the left eye and nasal half of the right eye The optic nerve (CN II) arises from axons of ganglion cells of the retina, which converge at the optic disc. The optic nerve leaves the orbital cavity by passing through the optic foramen (also called optic canal) of the ...
Argyll Robertson Pupil
... accepted as a pathognomonic sign of neurosyphilis, and this sign has since been identified with other central nervous system diseases as well. PHYSIOLOGY Light Reflex From an inverted image on the light-sensitive cells of the retina, impulses pass through the optic nerve to the optic tract via the o ...
... accepted as a pathognomonic sign of neurosyphilis, and this sign has since been identified with other central nervous system diseases as well. PHYSIOLOGY Light Reflex From an inverted image on the light-sensitive cells of the retina, impulses pass through the optic nerve to the optic tract via the o ...
The Limbal Epithelial Progenitors in the Limbal Niche Environment
... key characteristics of stem cells are high capacity for self-renewal and poor differentiation. They have long cell cycle time, long life span, error-free proliferation, and the ability to divide in an asymmetric way. Asymmetric division allows one of the daughter cells to maintain stemness and reple ...
... key characteristics of stem cells are high capacity for self-renewal and poor differentiation. They have long cell cycle time, long life span, error-free proliferation, and the ability to divide in an asymmetric way. Asymmetric division allows one of the daughter cells to maintain stemness and reple ...
![8Senses-vision [Compatibility Mode]](http://s1.studyres.com/store/data/001227808_1-f38b027a4ee4539e91b0915f76210b7a-300x300.png)
8Senses-vision [Compatibility Mode]
... Homeostatic Imbalances of the Eyes Night blindness—inhibited rod function that hinders the ability to see at night Color blindness—genetic conditions that result in the inability to see certain colors Due to the lack of one type of cone (partial color blindness) ...
... Homeostatic Imbalances of the Eyes Night blindness—inhibited rod function that hinders the ability to see at night Color blindness—genetic conditions that result in the inability to see certain colors Due to the lack of one type of cone (partial color blindness) ...
Scholarly Interest Report
... Currently, our research is aimed at further elucidating the role of guidance molecules during cornea development. Since cornea regeneration recapitulates development, we will extrapolate our studies to cornea wound healing. In addition to the chick, these studies will involve the mouse as a genetic ...
... Currently, our research is aimed at further elucidating the role of guidance molecules during cornea development. Since cornea regeneration recapitulates development, we will extrapolate our studies to cornea wound healing. In addition to the chick, these studies will involve the mouse as a genetic ...
Functional Anatomy of the Human Visual Pathway
... The lateral geniculate body (LGB), or lateral geniculate nucleus (LGN), is the last synaptic component of the afferent pathway prior to arrival at the primary visual cortex. About 1.2 million tract fibers on each side project onto about 5 million neurons of the optic radiations, which constitute the ...
... The lateral geniculate body (LGB), or lateral geniculate nucleus (LGN), is the last synaptic component of the afferent pathway prior to arrival at the primary visual cortex. About 1.2 million tract fibers on each side project onto about 5 million neurons of the optic radiations, which constitute the ...
Outer Ear - bYTEBoss
... It contains two sacs: 1. The saccule which detects vertical motion (like the Spaceshot at Galaxyland). 2. The utricle, which detects head tilt. ...
... It contains two sacs: 1. The saccule which detects vertical motion (like the Spaceshot at Galaxyland). 2. The utricle, which detects head tilt. ...
Senior Facilities Lighting PDF
... The human eye is a sophisticated piece of machinery; it is able to adjust to a wide range of light levels, including about 10,000 footcandles on a sunny day to about 0.01 footcandles under full moonlight. However, optimum ranges of light levels have been established for various tasks so that those t ...
... The human eye is a sophisticated piece of machinery; it is able to adjust to a wide range of light levels, including about 10,000 footcandles on a sunny day to about 0.01 footcandles under full moonlight. However, optimum ranges of light levels have been established for various tasks so that those t ...
Vestibular
... endolymph, depolarizing the cell membrane (see Fig. 7). This depolarization in turn causes voltage-gated calcium channels at the base of the hair cells to open, allowing Ca++ to enter the cell. The influx of Ca++ causes synaptic vesicles to release their transmitter (aspartate or glutamate) into the ...
... endolymph, depolarizing the cell membrane (see Fig. 7). This depolarization in turn causes voltage-gated calcium channels at the base of the hair cells to open, allowing Ca++ to enter the cell. The influx of Ca++ causes synaptic vesicles to release their transmitter (aspartate or glutamate) into the ...
Raneat Cohen
... This case is unique both in its presentation and clinical findings. The patient's complaint of acute vision loss is unusual. This could possibly be explained by an acute embolic event or possibly a discovery phenomenon as record review indicates gradual loss of vision over several years. The patient ...
... This case is unique both in its presentation and clinical findings. The patient's complaint of acute vision loss is unusual. This could possibly be explained by an acute embolic event or possibly a discovery phenomenon as record review indicates gradual loss of vision over several years. The patient ...
Chapter 9 – The Senses
... aqueous humor. Retina – contains microscopic receptor cells called rods and cones. ○ Rods – ○ Cones – ○ Fovea – ...
... aqueous humor. Retina – contains microscopic receptor cells called rods and cones. ○ Rods – ○ Cones – ○ Fovea – ...
The Senses PPT
... aqueous humor. Retina – contains microscopic receptor cells called rods and cones. ○ Rods – ○ Cones – ○ Fovea – ...
... aqueous humor. Retina – contains microscopic receptor cells called rods and cones. ○ Rods – ○ Cones – ○ Fovea – ...
chapter 15 the special senses
... channels open in synaptic terminals. 3 Neurotransmitter is released continuously. ...
... channels open in synaptic terminals. 3 Neurotransmitter is released continuously. ...
Special Senses Assignment
... j. Lacrimal glands k. Conjunctiva 3. Use these words to fill in the blanks below: lens, cerebrum, optic a. The eye receives light rays and sends to _________ nerve which then carries the impulses to the brain to give us sight or vision. b. Light rays that enter the eye follow this pathway: cornea, _ ...
... j. Lacrimal glands k. Conjunctiva 3. Use these words to fill in the blanks below: lens, cerebrum, optic a. The eye receives light rays and sends to _________ nerve which then carries the impulses to the brain to give us sight or vision. b. Light rays that enter the eye follow this pathway: cornea, _ ...
Pupillary diameter and reaction to light in preterm
... reflex constriction. 1 Tunica vasculosa lentis regresses between 28 and 34 weeks' gestation. 10 However, no anatomical evidence has been found to suggest that this membrane is linked to the iris. Indeed, very immature neonates, born at less than 28 weeks' gestation, are screened before the regressio ...
... reflex constriction. 1 Tunica vasculosa lentis regresses between 28 and 34 weeks' gestation. 10 However, no anatomical evidence has been found to suggest that this membrane is linked to the iris. Indeed, very immature neonates, born at less than 28 weeks' gestation, are screened before the regressio ...
Chapter 22 – Red and Painful Eye
... Flashlight is swung from one eye to the other (not obstructing their visual line) The direct and consensual light reflexes are assessed a. These are mediated through cranial nerves - the afferent, or sensory, limb corresponds with the optic nerve (CN II), while the efferent, motor, limb corresponds ...
... Flashlight is swung from one eye to the other (not obstructing their visual line) The direct and consensual light reflexes are assessed a. These are mediated through cranial nerves - the afferent, or sensory, limb corresponds with the optic nerve (CN II), while the efferent, motor, limb corresponds ...
PDF
... coherence tomography (OCT) were performed in three patients with retinal phototoxicity lesions. Fluorescein angiography depicted a window defect. OCT exhibited hyporeflectivity at the outer foveal retina and fragmentation of the inner reflective layers, corresponding to the junction between the inne ...
... coherence tomography (OCT) were performed in three patients with retinal phototoxicity lesions. Fluorescein angiography depicted a window defect. OCT exhibited hyporeflectivity at the outer foveal retina and fragmentation of the inner reflective layers, corresponding to the junction between the inne ...
classification of functional components of cranial nerves
... inferior oblique – rotates eye laterally levator palpabre superiorous- lifts eyelid ...
... inferior oblique – rotates eye laterally levator palpabre superiorous- lifts eyelid ...
Dolomedes aquaticus (Pisauridae)
... in rows, each row separated by pigmented glial cells, but within a row, rhabdomeres from neigh bouring cells are contiguous so that coupling between cells from the same row seems a possible way of increasing absolute sensitivity for night vision. When the spider submerges, an air-layer is held over ...
... in rows, each row separated by pigmented glial cells, but within a row, rhabdomeres from neigh bouring cells are contiguous so that coupling between cells from the same row seems a possible way of increasing absolute sensitivity for night vision. When the spider submerges, an air-layer is held over ...
THE NEURAL TUBE AND ITS SUBDIVISIONS
... middorsal region in front of the primitive node. Its lateral edges soon elevate to form the neural folds • With further development, the neural folds continue to elevate, approach each other in the midline, and finally fuse, forming the neural tube • The notochord (a midline rod of cells) stimulates ...
... middorsal region in front of the primitive node. Its lateral edges soon elevate to form the neural folds • With further development, the neural folds continue to elevate, approach each other in the midline, and finally fuse, forming the neural tube • The notochord (a midline rod of cells) stimulates ...
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.