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Lastly, there are three or four layers of squamous cells, with flattened nuclei. The layers of the epithelium are constantly undergoing mitosis. Basal and wing cells migrate to the anterior of the cornea, while squamous cells age and slough off into the tear film. Central thickness of corneal epithelial layer is approximately 50 to 52 μm. [2]
Diagram of a human eye (horizontal section of the right eye) 1. Lens, 2. Zonule of Zinn or Ciliary zonule, 3. Posterior chamber and 4. Anterior chamber with 5. Aqueous humour flow; 6. Pupil, 7. Corneosclera or Fibrous tunic with 8. Cornea, 9. Trabecular meshwork and Schlemm's canal. 10. Corneal limbus and 11. Sclera; 12. Conjunctiva, 13. Uvea ...
The pupil of the human eye can range in size from 2 mm to over 8 mm to adapt to the environment. The human eye can detect a luminance from 10 −6 cd/m 2, or one millionth (0.000001) of a candela per square meter to 10 8 cd/m 2 or one hundred million (100,000,000) candelas per square meter.
The first stage of lens formation takes place when a sphere of cells formed by budding of the inner embryo layers comes close to the embyro's outer skin. The sphere of cells induces nearby outer skin to start changing into the lens placode. The lens placode is the first stage of transformation of a patch of skin into the lens.
The basic light-processing unit of eyes is the photoreceptor cell, a specialized cell containing two types of molecules bound to each other and located in a membrane: the opsin, a light-sensitive protein; and a chromophore, the pigment that absorbs light. Groups of such cells are termed "eyespots", and have evolved independently somewhere ...
It forms the outermost layer of the skin and the inner lining of the mouth, esophagus and vagina. [2] In the epidermis of skin in mammals, reptiles, and birds, the layer of keratin in the outer layer of the stratified squamous epithelial surface is named the stratum corneum. Stratum corneum is made up of squamous cells which are keratinized and ...
Eye formation in the human embryo begins at approximately three weeks into embryonic development and continues through the tenth week. [1] Cells from both the mesodermal and the ectodermal tissues contribute to the formation of the eye.
The corneal endothelium is a single layer of endothelial cells on the inner surface of the cornea.It faces the chamber formed between the cornea and the iris. The corneal endothelium are specialized, flattened, mitochondria-rich cells that line the posterior surface of the cornea and face the anterior chamber of the eye.