2017 Group Project 4: Difference between revisions
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= Anatomy of the eye = | |||
The eye is a complex structure which allows a variety of species to intake and process visual information from the world around us. | The eye is a complex structure which allows a variety of species to intake and process visual information from the world around us. | ||
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ref: https://ap01-a.alma.exlibrisgroup.com/view/uresolver/61UNSW_INST/openurl?ctx_enc=info:ofi/enc:UTF-8&ctx_id=10_1&ctx_tim=2017-09-07T14%3A11%3A09IST&ctx_ver=Z39.88-2004&url_ctx_fmt=info:ofi/fmt:kev:mtx:ctx&url_ver=Z39.88-2004&rfr_id=info:sid/primo.exlibrisgroup.com-scopus&req_id=&rft_val_fmt=info:ofi/fmt:kev:mtx:book&rft.genre=bookitem&rft.atitle=Anatomy%20of%20the%20eye&rft.jtitle=&rft.btitle=Handbook%20of%20Visual%20Display%20Technology&rft.aulast=Garhart&rft.auinit=C&rft.auinit1=&rft.auinitm=&rft.ausuffix=&rft.au=Garhart,%20C.&rft.aucorp=&rft.date=20120101&rft.volume=1&rft.issue=&rft.part=&rft.quarter=&rft.ssn=&rft.spage=73&rft.epage=82&rft.pages=73-82&rft.artnum=&rft.issn=&rft.eissn=&rft.isbn=9783540795674&rft.sici=&rft.coden=&rft_id=info:doi/10.1007/978-3-540-79567-4_2.1.1&rft.object_id=&rft.eisbn=&rft.edition=&rft.pub=Springer%20Berlin%20Heidelberg&rft.place=&rft.series=&rft.stitle=&rft.bici=&rft_id=info:bibcode/&rft_id=info:hdl/&rft_id=info:lccn/&rft_id=info:oclcnum/&rft_id=info:pmid/&rft_id=info:eric/((addata/eric}}&rft_dat=%3Cscopus%3E2-s2.0-84923867273%3C/scopus%3E,language=eng,view=UNSWS&svc_dat=single_service&env_type=test | ref: https://ap01-a.alma.exlibrisgroup.com/view/uresolver/61UNSW_INST/openurl?ctx_enc=info:ofi/enc:UTF-8&ctx_id=10_1&ctx_tim=2017-09-07T14%3A11%3A09IST&ctx_ver=Z39.88-2004&url_ctx_fmt=info:ofi/fmt:kev:mtx:ctx&url_ver=Z39.88-2004&rfr_id=info:sid/primo.exlibrisgroup.com-scopus&req_id=&rft_val_fmt=info:ofi/fmt:kev:mtx:book&rft.genre=bookitem&rft.atitle=Anatomy%20of%20the%20eye&rft.jtitle=&rft.btitle=Handbook%20of%20Visual%20Display%20Technology&rft.aulast=Garhart&rft.auinit=C&rft.auinit1=&rft.auinitm=&rft.ausuffix=&rft.au=Garhart,%20C.&rft.aucorp=&rft.date=20120101&rft.volume=1&rft.issue=&rft.part=&rft.quarter=&rft.ssn=&rft.spage=73&rft.epage=82&rft.pages=73-82&rft.artnum=&rft.issn=&rft.eissn=&rft.isbn=9783540795674&rft.sici=&rft.coden=&rft_id=info:doi/10.1007/978-3-540-79567-4_2.1.1&rft.object_id=&rft.eisbn=&rft.edition=&rft.pub=Springer%20Berlin%20Heidelberg&rft.place=&rft.series=&rft.stitle=&rft.bici=&rft_id=info:bibcode/&rft_id=info:hdl/&rft_id=info:lccn/&rft_id=info:oclcnum/&rft_id=info:pmid/&rft_id=info:eric/((addata/eric}}&rft_dat=%3Cscopus%3E2-s2.0-84923867273%3C/scopus%3E,language=eng,view=UNSWS&svc_dat=single_service&env_type=test | ||
=Eye Development= | |||
== Timeline of Eye Development == | == Timeline of Eye Development == |
Revision as of 22:24, 10 September 2017
2017 Student Projects | |||
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Anatomy of the eye
The eye is a complex structure which allows a variety of species to intake and process visual information from the world around us.
In humans the wall of the eye has 3 basic layers: - An outer fibrous layer containing the posterior sclera and anterior cornea. The sclera --- - A vascular middle layer containing the choroid - An inner receptive layer containing the retina
Anterior structure
Eye Development
Timeline of Eye Development
Week 3 - 4
- Optic vesicles
- Lens placode
Week 5 - 6
- Optic cup
- Lens vesicle
- Hyaloid artery
Week 7 - 8
- Cornea
- Anterior Chamber
- Lens
- Retina
Week 9 - 15
- Iris
- Cillary Body
Week 8 - 10
- Eyelids
Carnegie Stages
Development of the eye components
The eyes are derived from four sources:
- The neuroectoderm of the forebrain forms
- Retina
- Posterior layers of the iris
- The optic nerve.
- The surface ectoderm of the head forms
- The lens of the eye
- The corneal epithelium.
- The mesoderm between the neuroectoderm and the surface ectoderm forms
- The fibrous and vascular coats of the eye
- The neural crest cells forms
- Choroid
- Sclera
- Corneal endothelium
Overview of eye development
The eye starts to develop at 22 days. The optic grooves (sulci) appears in the neural folds at the cranial end of the embryo. When the neural fold fuse to form the forebrain, the optic grooves will form optic vesicles. The optic vesicles are continuous cavities from the cavity of the forebrain and project from the wall of the forebrain and into the mesenchyme. The optic vesicle extends from the diencephalon and will come in contact with the surface ectoderm of the head. This induces the formation of a lens placode. The surface ectoderm near the optic vesicles will thicken and form the lens placodes. The lens placodes will sink into the surface ectoderm and form lens pits. The edges of the lens pits will travel towards each other and fuse to form round lens vesicles, which will later lose connection with the surface ectoderm. The optic vesicles do also keep developing - they will form double-walled optic cups which are connected to the brain by the optic stalk. The two layers of the optic cup will differentiate in different directions. The cells of the outer layer will produce melanin pigment and later become the pigmented retina. The cells of the inner layer of the optic cup will proliferate fast and develop glia, ganglion cells, interneurons and light-sensitive photoreceptor neurons. These cells are in the neural retina. The ganglion cells of the retina are neurons that send signal to the brain. The axons of the ganglion cells of the neural retina will grow in the wall of the optic stalk. The cavity in the optic nerve will start disappearing, and instead, the axons of the ganglion cells will form the optic nerve. The optic stalk is now the optic nerve [1]
The optic cups will fold inwards around the lens while the lens vesicles have grown inwards so they have fully lost their connection with the surface ectoderm, which locates them in the cavities of the optic cups. The retinal fissures (linear grooves) will develop and cover the ventral surface of the optic cups and down to the optic stalk. The retinal fissures contain vascular mesenchyme and hyaloid blood vessels will develop here. The hyaloid artery supplies the structures in the eye with blood and the hyaloid vein will return the blood from these structures.
Formation of the optic vesicle
It is a specific area of the neural ectoderm that will become the optic vesicle - this happens because of a group of transcription factors - Six3, Pax6, and Rx1. These transcription factors are expressed in the most anterior tip of the neural plate. This area will split into bilateral regions and form the optic vesicles. The Pax6 protein has shown to be especially important for the development of the lens and retina. This protein is important for photoreceptive cells in all phyla. Pax 6 is also present in the murine forebrain, hindbrain, and nasal placodes, but the eyes are most sensitive its absence [2].
The sonic hedgehog gene is important for the separation of the single eye field into two fields. If this gene is inhibited, the eye field will not split which will result in cyclopia, a single eye in the center of the face [3].
Lens
Human lens induction occurs at around 28 days and is completed around day 56. The surface ectoderm will thicken near the optic vesicle and create the lens placode and later form the lens vesicle [4]. Lens cells come from ectoderm and differentiate into either lens fibers or the lens epithelium. The anterior monolayer of epithelial cells of the lens will create the lens epithelium, which makes the sheet of cuboidal epithelium covering the anterior surface of the lens. The posterior lens vesicle cells will produce the linear primary fibre cells aligned parallel to the optic axis. These fibres will create the lens mass and form the embryonic lens nucleus. The lens epithelial cells will keep proliferating and produce new cells which generate a secondary lens fiber cells. This rows of cell will form the outer shells and keep the lens growing throughout life. This makes the eye lens unique - it will have an addition of new cells inside the surrounding capsule all the time [5].
Retina
5075778
Ciliary Body
z5177670
http://www.sciencedirect.com/science/article/pii/S0012160606014898?via%3Dihub
Iris
z5177670
Aquous Chambers
5075309
Cornea
z5177670
http://www.sciencedirect.com/science/article/pii/S1877117315000642
Choroid and Sclera
5075309
Eyelids
5075309
Lacrimal Glands
5075309
Extraocular muscles
5075778
<pubmed>26410132</pubmed> <pubmed>23071378</pubmed>
Common Abnormalities
We could talk briefly in this sections about the causes of short/long-sightedness and common causes of blindness at a developmental level - z3416557
Further Research
5117343 In the news, media, websites starting point: Macular Research: https://www.cera.org.au/research/macular-research/ > Bionic Eye - https://theconversation.com/artificial-vision-what-people-with-bionic-eyes-see-79758 Corneal Research: https://www.cera.org.au/research/corneal-research/ > Stem cells, corneal transplant Cellular Reprogramming: https://www.cera.org.au/cellular-reprogramming/ Glaucoma Research: https://www.cera.org.au/research/glaucoma-research/
Glossary
References
- ↑ https://www.ncbi.nlm.nih.gov/books/NBK10024/#
- ↑ https://www.ncbi.nlm.nih.gov/books/NBK10024/#
- ↑ https://www.ncbi.nlm.nih.gov/books/NBK10024/#
- ↑ http://www.sciencedirect.com/science/article/pii/S0014483510000448?via%3Dihub
- ↑ <pubmed>25406393</pubmed>
- ↑ <pubmed>23528534</pubmed>
Recent papers
Mark Hill (talk) 10:15, 14 August 2017 (AEST) OK Group 4 below are some starting places.
<pubmed limit=5>Eye+Development</pubmed>
z5075309 - <pubmed>26956898</pubmed>
External links
PubMed Searches: Eye Development | Vision Development
BMC Dev Biol Search: Eye Development