Medical School Histology Basics Eye VIBS 243 lab

Medical School Histology Basics Eye VIBS 243 lab Larry Johnson Texas A&M University

Aqueous humor Ref code #6 OUTLINE OVERVIEW CELLULAR STRUCTURES THROUGH WHICH LIGHT PASSES A. B. C. CORNEA LENS RETINA STRUCTURES WHICH INFLUENCE THE IMAGE A. B. C. IRIS CILIARY BODIES TRABECULAR MESHWORK Vitreous humor

Aqueous humor VITREOUS BODY (VITREOUS HUMOR) Ref code # 6, 10

Ref code #5 34412

192 Eye – conjuctiva on white of eye sclera Conjunctiva Stratified squamous epithelium with some goblet cells Ref code # 10

Eye 192 human and 34412 monkey Aqueous humor Connective tissue Nerve Posterior chamber 192 Retina Cornea Sclera Pupil Optic nerve Anterior chamber Lens Iris 34412 Vitreous body Chorioid layer Ciliary body

Ref code # 5, 6

192 Eye – corneal layers Stratified squamous Epithelium Bowman's membrane Corneal stroma Corneal endothelium Corneal fibroblasts Descemet's Membrane Ref code #6

292 corneal layers Iris of Eye (toluidine blue) Ciliary muscle: smooth muscle Sclera Lens Sclera-cornea junction (limbus) Aqueous humor Bowman's membrane Corneal stroma Aqueous humor Corneal endothelium Iris Descemet's Membrane Anterior chamber Iris Posterior chamber

292 Ciliary muscle: Ciliary smooth muscle processes Blood vessel lens Nerves Ciliary muscle 192

192 Eye – ciliary muscle Pupil Iris Artifactual space Conjunctival sac Sclera-cornea junction (limbus) Ciliary muscle Posterior chamber Ciliary processes Anterior chamber Ciliary muscle (smooth muscle)

192 Eye – secretory cells Pigmented cells of the ciliary processes become the dilator muscle of the iris Pigmented cells Secretory cells Iris Secretory cells become the pigmented cells of the iris Ciliary processes

292 Conjunctiva Eye (toluidine blue) Iris Ciliary muscle Trabecular meshwork Air Canal of Schlemm Anterior chamber Limbus Endothelium of trabecular meshwork is continuous with the transport endothelium of the cornea Ciliary processes Iris Posterior chamber

192 Eye – trabecular meshwork and canal of Schlemm Canal of Schlemm Limbus Trabecular meshwork Anterior chamber with aqueous humor Ciliary muscle

Canal of Schlemm Trabecular meshwork Iris Blood vessels Posterior chamber with aqueous humor Monkey eye 34412

mbe r 292 Eye (toluidine blue) cha Lens ule sc Len teri o Iris r ch am ber pupil Ref code # 10 Lens Pos Iris aps Ante rior Dilator muscle Constrictor muscle Pupil Cuboidal epithelium on anterior surface of lens Iris

292 Eye (toluidine blue) Lens cuboidal epithelium Lens capsule Iris constrictor smooth muscle Lens

Ref code # 10 The capsule is a shared basement membrane of the lens epithelium

Ref code # 10 The capsule is a shared basement membrane of the lens epithelium Lens

192 and 34412 Lens and iris Pigmented epithelium of iris Lens capsule teri o r ch am ber Iris Pos Iris Lens cuboidal epithelium 34412 Iris constrictor muscle is smooth muscle Lens anterior surface 192

292 Eye (toluidine blue) elongation of lens cuboidal cells at bow region Capsule Lens cuboidal epithelium on its anterior surface gives rise to elongated lens fibers in the bow region, and the shared basement membrane of these cells is the capsule Capsule flattened lens fibers Artifactual space 34412 No cuboidal epithelium on the posterior surface of the lens and the capsule is thinner there

34412 Eye monkey Sites of attachment of zonules to the lens’ capsule Anterior surface e rfac r su erio Ant Iris Poste rior su rface lens Ligaments (zonules) 192 lens One site of attachment of a zonule to the capsule on the lens on its posterior surface

Sclara 34412 Ciliary muscle Zonules 192 Lens fibers Capsule and cuboidal epithelium on the anterior surface of lens Thinner capsule on the posterior surface of the lens

34412 Eye monkey Capillary network in retina Pigmented layer of epithelial cells Elaborate network of vessels, the choroid plexus. Central artery of the retina

Ref code #5

34412 Cones Rods Ganglion cell layer Bipolar cells Vitreous body Retinal pigmented epithelium space actual Artif Photosensitive portion of rod and cone cells Retinal pigmented epithelium Artifactual space Sclera Venule in the choroid plexus

Rods Cones Photosensitive portion of rod and cone cells Retinal pigmented epithelium Nuclei of rod and cone cells = outer nuclear layer

Eye - Retina and choroid: Blood vessels in the retina 292 Artifact space Choroid plexus Melanin granules Retina Nucleus Retinal pigment epithelium

292 Retina (toluidine blue) Bipolar cells Photoreceptor cells Artifactual space Rods Optic nerve Capillary In retina Cones

Typical retina Ganglion cell layer Macula with top two layers pulled back to aid vision Bipolar cells Rods and cones Retinal pigmented epithelium

Conjunctiva Cornea a er l c S 192 lens Choroid plexus Cornea Iris Vitreous body Retina Sclera Lens Optic nerve Anterior chamber Posterior chamber Aqueous humor 292

34412 Pigmented epithelium Choroid Blind spot where optic nerve enters the retina Bipolar cell layer Ganglion cell layer Photosensitive region of rods and cones

292 Eye (toluidine blue) Blind spot where optic nerve enters the retina

34412 Choroid plexus Retina OPTIC CUP AND NERVE HEAD Retina

In summary Ref code # 6, 10

Many illustrations in these VIBS Histology You. Tube videos were modified from the following books and sources: Many thanks to original sources! 1. Alberts, et al. , 1989. Molecular Biology of the Cell. 2 nd Edition. Garland Publishing, Inc. New York. ISBN 0 -8240 -3695 -6. 2. Alberts, et al. , 1994. Molecular Biology of the Cell. 3 nd Edition. Garland Publishing, Inc. New York. ISBN 0 -8153 -1619 -4. 3. Bloom, W. and Fawcett, D. W. , 1968. A Textbook of Histology. 9 th Edition. W. B. Saunders Company. Philadelphia. Library of Congress #67 -17445. 4. Elias, H. et al. , 1978. Histology and Human Microanatomy. A Wiley Medical Publication. John Wiley & Sons, New York. ISBN 0 -47104929 -8. 5. Eroschenko, V. 2000. Di Fiore’s Atlas of Histology with Functional Correlations. 9 th Edition. Lippincott Williams & Wilkins. Philadelphia. ISBN 07817 -2676 -X. 6. Fawcett, D. W. , 1986. Bloom and Fawcett. A Textbook of Histology. 11 th Edition. W. B. Saunders Company. Philadelphia. ISBN 0 -72161729 -8. 7. Fawcett, D. W. , 1994. Bloom and Fawcett. A Textbook of Histology. 12 th Edition. Chapman and Hall. New York. ISBN 0 -412 -04691 -1. 8. Guyton, A. C. 1971. Textbook of Medical Physiology. 4 th Edition. W. B. Saunders Company. Philadelphia. Library of Congress # 74118589. 9. Ham, A. W. 1974. Histology. 7 th Edition. J. B. Lippincott Company. Philadelphia. ISBN 0 -397 -52062 -X. 10. Ham, A. W. and Cormack, D. H. 1979. Histology. 8 th Edition. J. B. Lippincott Co. Philadelphia. ISBN 0 -397 -52089 -1. 11. Junqueria, et al. , 1995. Basic Histology. 8 th Edition. Appleton and Lange. Norwalk, Connecticut. ISBN 08385 -0567 -8. 12. Junqueira, et al. , 1998. Basic Histology. 9 th Edition. Appleton and Lange. Stamford, Connecticut. ISBN 0 -8385 -0590 -2. 13. Knobil, E. et al. 1988. The Physiology of Reproduction. Volume 1. Raven Press. New York. ISBN 0 -88167 -281 -5. 14. Langley, et al. , 1974. Dynamic Anatomy and Physiology. 4 th Edition. Mc. Graw-Hill Book Company. New York. ISBN 0 -07 -036274 -2. 15. Mescher, A. L. , 2010. Junqueira’s Basic Histology Text and Atlas. 12 th Edition. Mc. Graw Hill Medical. New York. ISBN 978 -0 -07 -1604314. 16. Tuttle, W. W. and Schottelius, B. A. 1969. Textbook of Physiology. 16 th Edition. The C. V. Mosby Company. Saint Louis. Library of Congress # 7589848. 17. Varner, D. et al. 1991. Diseases and Management of Breeding Stallions. American Veterinary Publications. Goleta, California. ISBN 0939674 -33 -5. 18. Von Hagens, Gunther and A. Whalley, 2007. Body Worlds – The Anatomical Exhibition of Real Human Bodies. ISBN 978 -3 -937256 -04 -7 19. Weiss, L. 1983. Histology: Cell and Tissue Biology. 5 th Edition. Elsevier Biomedical. New York. ISBN 0 -444 -00716 -4. 20. Weiss, L. and Greep, R. 1977. Histology. 4 th Edition. Mc. Graw-Hill Book Company. New York. ISBN 0 -07 -069091 -X.

Questions on the eye 1. The integrity of the relationship among structures of the eye is produced/maintained by: a. supporting layer of the eye holding pressure b. precise regulation of pressure via aqueous humor production and outflow c. the bony structure of the sclera in mammals d. a and b e. a, b, and c 2. Which structure is not correctly paired with its function? a. the iris regulates the amount of light that reaches the retina b. ciliary bodies alter the shape of the lens by the attached zonules c. the trabecular meshwork enhances the outflow of vitreous humor d. the cornea focuses the image on the retina e. the retinal and choroid blood vessels provide nutrients to the retina 3. Which function(s) least match(s) that of the cornea? a. protection b. structural support c. filter out undesirable light rays d. focus image on photosensitive portion of the photoreceptor cells e. none of the above

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