Retina PDF

Retina Study online at https://quizlet.com/_euw2qm 1. Neural Retina Development Between weeks 4 to 6, cells in the inner layer of the optic cup (neural retina) proliferate and two zones are evident 2. Outer layer of the optic cup form the RPE 3. 2.5 months transient layer of Chievitz* separates inne...

Retina Study online at https://quizlet.com/_euw2qm 1. Neural Retina Development Between weeks 4 to 6, cells in the inner layer of the optic cup (neural retina) proliferate and two zones are evident 2. Outer layer of the optic cup form the RPE 3. 2.5 months transient layer of Chievitz* separates inner from outer neuroblastic layers of primitive retina 4. Innermost cells will differentiate into ganglion, amacrine and Müller cells 5. Outermost cells will differentiate in photoreceptors, horizontal and bipolar cells 6. As retinal cells continue developing the transient inner plexiform layer layer of Chievitz probably becomes a part of the 7. retinal lamination essentially is complete by 8. True or False: Photoreceptors outer segment are True not yet present, only present in the inner segment by month 4.5 9. Except macular area, ganglion cells have thinned 5.5 out to one to two layers by month 10. Inner nuclear layer has develop completely, include: 4.5 months amacrine, Müller, bipolar and horizontal cells 11. What type of configuration does a newborn retina adult configuration have? 12. thinner 1 / 17 Retina Study online at https://quizlet.com/_euw2qm Outer plexiform layer is _______, but line of synapses is established 13. Rod and cone inner and outer segments are fully contact pigment epdeveloped, and tips of outer segments... ithelium 14. Normal retinal vascular development begins at the optic disc at about 16 weeks' gestation 15. Angiogenesis then proceeds to extend the retinal 40 week in utero vasculature to the periphery by 16. In premature babies, retinal vascularization com- outside the uterus pletes 17. Early in gestation, may be differentiated by an increase in ________ in this macula area ganglion cells 18. The cone inner fibers elongate and adopt an oblique orientation as synapse with the cells of the inner nuclear layer forming the outer plexiform layer of Henle 19. Do Rods or Cones develop in the macula? Cones 20. Macular development continues for a few months after birth and may be dependent on a light stimulus 21. Retina Innermost layer of the eye Neural layer Its where light energy is transformed into a neural sign Laminar appearance 22. Retina extends from... the edge of the optic disc to the ora serrata 2 / 17 Retina Study online at https://quizlet.com/_euw2qm 23. Retina derives from the neural ectoderm 24. 10 layers of Retina 1. Retinal Pigment Epithelium 2. Photoreceptor Layer 3. Outer Limiting Membrane 4. Outer Nuclear Layer 5. Outer Plexiform Layer 6. Inner Nuclear Layer 7. Inner Plexiform Layer 8. Ganglion Cell Layer 9. Nerve Fiber Layer 10. Internal Limiting Membrane 25. Retinal Pigment Epithelium Single layer of pigmented cells Apical side faces the retina 26. RPE basal side lies adjacent to the basal membrane that is shared by the Bruch's membrane 27. RPE cells contain many organelles - Smooth and rough ER - Golgi apparatus - Lysosomes - Mitochondria - Phagosomes - Pigment cells 28. Two types of pigment cells are Melanosomes Lipofuscin (from phagocytosis) 29. RPE embryologically derived from the 3 / 17 Retina Study online at https://quizlet.com/_euw2qm outer layer of the optic cup 30. RPE contains a basal membrane that fuse to the Bruch's membrane 31. subretinal space (area of detachments) Loosely adherent to the retina - creates a space between the RPE and neural retina 32. RPE has a tight connection with the choroid 33. Main functions of RPE - Phagocytosis of photoreceptor outer segments - Transport of ions, water, and metabolites between the choroid and retina 34. Photoreceptor Layer has special sensory cells Contain photopigments that absorb photons of light 35. How many Rods in the photoreceptor layer? 120 million 36. How many cones in the photoreceptor layer? 6 - 8 million 37. Photoreceptor Layer divides - Outer and Inner segment (at the photoreceptor layer) - Outer fiber and Cell body (at the outer nuclear layer) - Inner fiber and Synaptic terminal (at 4 / 17 Retina Study online at https://quizlet.com/_euw2qm the outer plexiform layer) 38. rods terminal Spherule 39. cones terminal Pedicle 40. Outer Segment of photoreceptor layer Contain discs that surround the photopigment molecules 41. Outer segment of both rods and cones contains hundreds (500-1000)... of lipid bilayered discs that are surrounded by a cell membrane 42. Inner Segment of photoreceptor layer Contain the cell organelles Area of metabolic activity and photopigment synthesis 43. cilium used a transportation to the outer segment where it is incorporated into discs 44. Two regions of Inner Segment of photoreceptor layer - Myoid - Elipsoid 45. Myoid - Inner layer - Location of protein synthesis 46. Myoid Contains RER, Golgi 47. Elipsoid Outer layer paced with mitochondria - ATP production 5 / 17 Retina Study online at https://quizlet.com/_euw2qm 48. True or False: Photoreceptors contains very few False; contains hundiscs dreds of disc 49. Each disc contains thousands of _________mol- photopigment ecules (Rhodopsin and Iodopsin) 50. photopigment Responsible for the light absorption 51. Rods Used for scotopic vision Detects objects at low levels of illumination 52. Rods density is greatest About 5 mm concentrically from the fovea in an area known as the rod ring 53. Rod disc contain rhodopsin, what wavelength does it absorb? - Absorbs protons maximally at 507nm - Does not detect color 54. Cones Used for photopic vision Contains three different pigment molecules 55. Each pigment molecule is activated by the absorption of light in a specific range in the color spectrum 56. Outer (External) Limiting Membrane Barrier Is not truly a membrane Do not contain cells 6 / 17 Retina Study online at https://quizlet.com/_euw2qm 57. OLM is band of desmosomal attachments (zonula Müller cells and the inadherents) between ner segments of photoreceptors 58. OLM Function Provides structure and act as a barrier for large metabolites 59. Outer Nuclear Layer Contains cell bodies of Rodes and Cones 60. Outer Plexiform Layer Area where rod spherules and cone pedicles synapse with the dendrites of bipolar and horizontal cells 61. The Outer Plexiform Layer at the macular area is Henle's fiber layer known as 62. Is the only layer that receives blood supply form Outer Plexiform Layer the choroid and retina (CRA) 63. The first synapse in the visual pathway occurs at first and second order the Outer Plexiform Layer between neurons 64. Describe the external and internal bands of the Outer Plexiform Layer -wide external band composed of inner fibers of rods and cones - narrow inner band consisting of synapses between photoreceptor cells and cells from the inner nuclear layer (horizontal and bipolar cells) 65. Rod spherules and cone pedicles synapse with bipolar cell dendrites 7 / 17 Retina Study online at https://quizlet.com/_euw2qm 66. Each rod spherule can synapse with 1 to 4 bipolar cells 67. Rods synapse with one type of bipolar cell 68. Which is larger, the cone pedicles or the rod spherule? cone pedicles 69. Horizontal cell processes synapse with bipolar dendrites and contact other horizontal processes via gap junctions 70. Inner Nuclear Layer contains the cell bodies of - Horizontal cells - Bipolar cells - Amacrine cells - Müller cells - Interplexiform cells 71. Horizontal cells synapse with photoreceptors, bipolar and other horizontal cells 72. Horizontal cells synapse with photoreceptors in a triad form 73. Horizontal cells modify the information that reaches the bipolar cells by providing lateral inhibition, which play a role in the complex process of visual integration 74. Inner Plexiform Layer - Location of synapse between second and third order neurons in visual pathway - Layer where bipolar, amacrine and ganglion cells form connections - Ganglion dendrites synapse with bipolar axons 8 / 17 Retina Study online at https://quizlet.com/_euw2qm 75. Synapses between ganglion dendrites and bipo- amacrine cells lar axons are modified by 76. Inner Plexiform Layer begin the processing of motion detection and changes in brightness, as recognition of contrast and hue 77. Bipolar cells and amacrine cells have opposite effects on ganglion cells - Bipolar cells increase stimulation of ganglion cells - Amacrine cells decrease stimulation of ganglion cells 78. Ganglion Cell Layer Layer where ganglion cell bodies are located 1 to 2 layers thick In the macular area increase to 4 to 7 layers 79. Every ganglion cell has a single axon and each axon terminates in the LGN 80. How many different types of ganglion cells? 18 81. What are the two broad ganglion cells? - P-cells - M-cells 82. P- cells - Parvocellular cells - Small diameter axons - Sensitive to color and fine detail - Project to the par9 / 17 Retina Study online at https://quizlet.com/_euw2qm vocellular layer of the LGN 83. Which is more common P cells or M cells? P cells 84. The most common P cells are the Midget ganglion cells 85. Midget ganglion cells Have a single dendrite (in the fovea) that synapses with one midget bipolar cell Allow information to be carried 86. M- cells - Magnocellular cells - Larger diameter axons - Sensitive to dim changes in illumination - Project to the magnocellular layer of the LGN 87. Nerve Fiber Layer - Axons of ganglion cells which collectively form the optic nerve - Thickest at the optic nerve head margin (most superiorly and inferiorly) where a large proportion of axons enter the nerve 88. Is the Nerve Fiber Layer present in the fovea? No 89. Papillomacular bundle NFL fibers that extend from the macula to the optic disc 10 / 17 Retina Study online at https://quizlet.com/_euw2qm 90. Internal Limiting Membrane Innermost boundary of the retina 91. Internal Limiting Membrane is comprised of footplates of Müller's cells (covered by a basement membrane) bound to vitreous humor fibrils 92. Müller's cells presences in the macula vs optic disc Present over the macula Absent over optic disc where astrocytes replace the Müller cells here 93. Neuroglial Cells Cells that provide structure, support and protection to the retina No role in signal processing 94. Type of Neuroglial Cells - Müller cells - Microglial cells - Astrocytes 95. Müller cells Most common Extend from ELM to ILM Not found within photoreceptor layer 96. Müller cells function Structural function Provide nutrients to the retina, role in glycogen metabolism 97. where is Müller cells mostly found ? Most Müller cell bodies are located at the INL 11 / 17 Retina Study online at https://quizlet.com/_euw2qm Some bodies are located in the ganglion layer 98. Microglial cells Phagocytic cells Respond to inflammation and/or injury 99. Where is Microglial cells found? Found in all layers of the retina 100. Astrocytes Star shaped Most concentration found in the inner layers of the retina Fibrous cells 101. Astrocytes function Provide structure to nerve fibers and capillaries 102. Outer 5 layers receive blood supply from the choroid (short posterior ciliary arteries) 103. Inner 5 layers receive blood supply from Central Retinal Artery 104. Which layer received from both CRA and the choroid? OPL 105. the CRA forms two capillary networks - One in the INL (deep capillary network) - One in the NFL (superficial capillary network) 106. Cilioretinal Artery - Artery is branch of the choriocapillaris (SPCA) - Nourishes the macula 12 / 17 Retina Study online at https://quizlet.com/_euw2qm 107. Is Cilioretinal Artery present in the entire popula- No, just present in tion? 15-20% of the population 108. What happens if a Cilioretinal Artery is present during a CRAO occlusion? allows the macular to be spared 109. Two regions of the Retina 1. Peripheral 2. Central 110. Peripheral region of the retina Detects gross form and motion Rods dominate 111. Central region of retina Specialized for visual acuity Rich in cones Has more ganglion cells per area Small portion of the retina 112. Macula Lutea Dark, pigmented region in the posterior pole Responsible for seeing color and detail 113. Macula Lutea contains two major xanthophyll pig- - Lutein ments - Zeaxanthin 114. Zeaxanthin Apparently act as filters absorbing short wavelength visible light to reduce chromatic aberration Also have suggest of an antioxidant effect, 13 / 17 Retina Study online at https://quizlet.com/_euw2qm protective role against UVR damage 115. Where is Zeaxanthin mostly located? this pigments are located throughout the retina, but the greatest concentration is in the macula 116. Macula Lutea occupied area approximately 5.5 mm in diameter 117. Entire macula region consists in: - Fovea - Parafovea - Perifovea 118. The center of Macula Lutea is approximately 3.5 mm lateral to the edge of the disc and approximately 1mm inferior to the center of the disc 119. Choroidal capillary bed in the Macula Lutea is thicker 120. The pigment epithelial cells in Macula Lutea are taller and contain more pigment 121. Fovea Is a 1.5mm diameter circle Specialized for discrimination of detail and color vision 122. clivus - The curved wall of the depression of fovea - gradually slopes to the floor that is the foveola 14 / 17 Retina Study online at https://quizlet.com/_euw2qm 123. foveal avascular zone length Capillary free zone of 0.4 to 0.5 mm in diameter 124. Why is there a foveal avascular zone? Allow light pass unobstructed into the photoreceptor outer segment 125. Foveola - Shallow depression in the center (retinal neurons are displaced leaving only cones in the center) foveola. - Area of best visual acuity 126. Foveola diameters about 0.35 mm 127. What is the Foveola concentration of cones and - Highest concentrarods? tion of cones (199,000 to 300,000 per square millimeter) - No rods within the central 1 degree of the foveola 128. Does the foveola contain bipolar and ganglion cells? Nope 129. Retinal layers in the foveola: - RPE - Photoreceptor layer - OLM - ONL - Henle's fiber layer - ILM 130. True or False: No NFL in the fovea or foveola True 131. Henle's fiber layer 15 / 17 Retina Study online at https://quizlet.com/_euw2qm - Contains longer axons of photoreceptors - Oblique course to reach the displaced bipolar and horizontal cells - Region of the OPL 132. Parafovea 0.5 mm zone that surround fovea Inner nuclear layer can be 12 cells thick and the ganglion cell layer 7 cells thick 133. Contains largest accumulation of retinal bipolar Parafovea and ganglion cells 134. Perifovea 1.5mm that surrounds parafovea Ganglion cell layer is 4 cells thick and ends at the periphery with one cell thick 135. What occurs the the Henle's layers in the perifovea? The fibers of Henle's layer revert to the usual orientation of the OPL 136. What occurs to rod density in the perifovea Rod density begins to increase around 1.2 to 1.7mm from fovea 137. Peripheral Retina Few blood vessels Ora serrata is the peripheral termination of the retina Firm attachment be16 / 17 Retina Study online at https://quizlet.com/_euw2qm tween the retina and vitreous 138. What occurs rods in the peripheral retina? Rods disappear and are replaced by malformed cones 139. What occurs to the Nuclear layers in the peripher- Nuclear layers merge al retina? with the plexiform layers 140. What happens to the RPE at the peripheral retina RPE continuous with the outer pigmented epithelium of the ciliary body 141. What happens to the Neural retina at the periph- Neural retina beeral retina? comes a single layer of irregular columnar cells that continue as the non- pigmented epithelium of the ciliary body 142. Retinal Function Light passes through most of the retinal layers before reaching and stimulating the photoreceptor outer segment discs 143. ________of photoreceptors,________of bipolar 128 million; 35 million; cells and 1.5 million ________of ganglion cells receive the neural message and the info pass tough the optic nerve to the visual pathway 17 / 17