Sensory - Vision Development: Difference between revisions
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===Carnegie Stages - Eye=== | ===Carnegie Stages - Eye=== | ||
The following data is from a study of human embryonic carnegie stages<ref><pubmed>7364662</pubmed></ref> and other sources. | {| | ||
| The following data is from a study of human embryonic carnegie stages<ref><pubmed>7364662</pubmed></ref> and other sources. | |||
* [[Carnegie_stage_10|Stage 10]] - optic primordia appear. | * [[Carnegie_stage_10|Stage 10]] - optic primordia appear. | ||
* [[Carnegie_stage_11|Stage 11]] - right and left optic primordia meet at the optic chiasma forming a U-shaped rim. | * [[Carnegie_stage_11|Stage 11]] - right and left optic primordia meet at the optic chiasma forming a U-shaped rim. | ||
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* [[Carnegie_stage_20|Stage 20]] - The lens cavity is lost and a lens suture begins to form. The inner canthus is established. | * [[Carnegie_stage_20|Stage 20]] - The lens cavity is lost and a lens suture begins to form. The inner canthus is established. | ||
* [[Carnegie_stage_23|Stage 23]] - The retina comprises the pigmented layer, external limiting membrane, proliferative zone, external neuroblastic layer, transient fiber layer, internal neuroblastic layer, nerve fiber layer, and internal limiting membrane. Eyelids closure is complete (Note - shown as still open in the Kyoto embryo). | * [[Carnegie_stage_23|Stage 23]] - The retina comprises the pigmented layer, external limiting membrane, proliferative zone, external neuroblastic layer, transient fiber layer, internal neuroblastic layer, nerve fiber layer, and internal limiting membrane. Eyelids closure is complete (Note - shown as still open in the Kyoto embryo). | ||
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| valign=bottom|{{SlideStage22-08}}<br>{{SlideStage22-08-eye}} | |||
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==Lens== | ==Lens== | ||
[[File:Stage_22_image_155.jpg|thumb|Human Lens (stage 22)]] | [[File:Stage_22_image_155.jpg|thumb|Human Lens (stage 22)]] |
Revision as of 19:57, 11 September 2014
Embryology - 27 Apr 2024 Expand to Translate |
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Introduction
These notes introduce the development of the eye: induction and regional specification of the eye structures, maturation and formation of retina and optic tectum neuronal connections. The adult eye has contributions from several different embryonic layers eventually forming neuronal, supportive connective tissue, optical structures, and muscular tissues. Additional pages are being developed to cover specific issues of this anatomical structure.
Senses Links: Introduction | placode | Hearing and Balance hearing | balance | vision | smell | taste | touch | Stage 22 | Category:Sensory |
Some Recent Findings
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More recent papers |
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This table allows an automated computer search of the external PubMed database using the listed "Search term" text link.
More? References | Discussion Page | Journal Searches | 2019 References | 2020 References Search term: Vision Development <pubmed limit=5>Vision Development</pubmed> Search term: Vision Embryology <pubmed limit=5>Vision Embryology</pubmed> |
Timeline
Embryonic Development
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Carnegie Stages - Eye
The following data is from a study of human embryonic carnegie stages[5] and other sources.
LensThe lens or crystalline lens or aquula (Latin, aquula = a little stream) has a key role in focussing light (with the cornea) upon the neural retina. The lens embryonic origin is from surface ectoderm of the sensory placodes that form in the head region (More? Week 4 - Placodes). The lens focusses by refracting light as it passes through the biconvex lens, which can be altered in shape (accommodation) by surrounding ciliary muscles. These ciliary muscles are activated (contracted) by parasympathetic innervation from the ciliary ganglion itself innervated by the oculomotor nerve (Cranial Nerve III) (More? Cranial Nerves). surface ectoderm -> lens placode -> lens pit -> lens vesicle -> lens fibres -> lens capsule and embryonic/fetal nucleus.
Retinotopic MapThis neuroscience term describes how the developing retina is precisely "mapped" onto the visual cortex through a series of signaling and activity dependent mechanisms. This follows from Hubel and Wiesel (1981 Nobel Prize in Physiology or Medicine) key discoveries (1959-70) of how in development system matching occurs in the visual system. The topographic map establishes an ordered neuronal connection between sensory structures and the central nervous system. The retinotectal map (eye to brain) of birds (lower vertebrates):
Retinal waves a form of coordinated spontaneous activity that occurs in the developing retina. These waves of electrical activity (action potentials) are thought to have a role in establishing the initial retinotopic map by correlating/coordinating the activity of neighbouring retinal ganglion cells. EphA/ephrin-A molecular signaling also thought to have a role in establishing the initial retinotopic map. Neural Crest
Extraocular MusclesExtraocular muscles are required to move the eye within the orbit. Their embryonic origin requires an interaction between the cranial mesoderm and the migrating neural crest cells. The following is from a recent paper comparing human to zebrafish muscle development.[7]
Additional ImagesHistoric ImagesReferencesOnline Textbooks
Reviews<pubmed>20855501</pubmed>| JCB The International Journal of Developmental Biology Vol. 48 Nos. 8/9 (2004) Eye Development Articles<pubmed>19541779</pubmed>
Bookshelf vision development Search PubmedSearch Pubmed: vision development | eye development | eye embryology | retina embryology | lens embryology
Terms
External LinksExternal Links Notice - The dynamic nature of the internet may mean that some of these listed links may no longer function. If the link no longer works search the web with the link text or name. Links to any external commercial sites are provided for information purposes only and should never be considered an endorsement. UNSW Embryology is provided as an educational resource with no clinical information or commercial affiliation.
Glossary Links
Cite this page: Hill, M.A. (2024, April 27) Embryology Sensory - Vision Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Sensory_-_Vision_Development
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