{"id":1373,"date":"2010-03-23T05:00:26","date_gmt":"2010-03-23T05:00:26","guid":{"rendered":"http:\/\/xromata.com\/?p=1373"},"modified":"2014-03-14T09:23:53","modified_gmt":"2014-03-14T09:23:53","slug":"%cf%81%ce%b1%ce%b2%ce%b4%ce%af%ce%b1-%ce%ba%ce%b1%ce%b9-%ce%ba%cf%89%ce%bd%ce%af%ce%b1","status":"publish","type":"post","link":"https:\/\/xromata.com\/?p=1373","title":{"rendered":"\u03a1\u03b1\u03b2\u03b4\u03af\u03b1 \u03ba\u03b1\u03b9 \u03ba\u03c9\u03bd\u03af\u03b1 – Rods and cones"},"content":{"rendered":"

Ραβδ\u03afα και κων\u03afα<\/o:p><\/font><\/span><\/u><\/span><\/p>\n

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Ναι, ο οφθαλμ\u03ccς, το μ\u03acτι, ε\u03afναι ο κ\u03cdριος υπε\u03cdθυνος για την λειτουργ\u03afα της \u03ccρασης, \u03ccμως βασικο\u03af παρ\u03acγοντες για την εκτ\u03adλεση της λειτουργ\u03afας αυτ\u03aeς ε\u03afναι τα μικροσκοπικ\u03ac ραβδ\u03afα και κων\u03afα. Χωρ\u03afς αυτ\u03ac, το μ\u03acτι αδυνατε\u03af να εκτελ\u03adσει τον προορισμ\u03cc του!<\/o:p><\/font><\/font><\/span><\/i><\/span><\/p>\n

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Η λειτουργ\u03afα της \u03ccρασης εξαρτ\u03acται απ\u03cc τα φωτοευα\u03afσθητα κ\u03cdτταρα του αμφιβληστροειδ\u03ae χιτ\u03ceνα, τα κων\u03afα και τα ραβδ\u03afα.<\/o:p><\/font><\/span><\/span><\/p>\n

Αυτο\u03af οι φωτο\u03cbποδοχε\u03afς ε\u03afναι απ\u03cc τα πιο πολ\u03cdπλοκα αισθητ\u03aeρια κ\u03cdτταρα που \u03adχουμε και χωρ\u03afζονται σε δυο τ\u03cdπους:<\/o:p><\/font><\/span><\/span><\/p>\n

Α) τα ραβδ\u03afα<\/b>, περ\u03afπου 120 – 140 εκατομμ\u03cdρια ρ\u03acβδους προσαρμοσμ\u03adνες για την αντ\u03afληψη του αμυδρο\u03cd φωτ\u03ccς και της νυχτεριν\u03aeς \u03ccρασης.<\/o:p><\/font><\/span><\/span><\/p>\n

Β) τα κων\u03afα<\/b>, περ\u03afπου 6 – 7 εκατομμ\u03cdρια κωνοειδε\u03afς ρ\u03acβδους, προσαρμοσμ\u03adνες να αντιλαμβ\u03acνονται τη φωτειν\u03ccτητα του φωτ\u03ccς της ημ\u03adρας και να το αναλ\u03cdουν σε χρ\u03ceματα. Τα κων\u03afα διαχωρ\u03afζονται σε τρεις τ\u03cdπους \u03ae \u03acλλως φασματικ\u03adς κατηγορ\u03afες.<\/o:p><\/font><\/span><\/span><\/p>\n

Τα ον\u03ccματα, ραβδ\u03afα και κων\u03afα, δ\u03ccθηκαν στους φωτοσυλλ\u03adκτες αυτο\u03cdς, \u03ccταν στις αρχικ\u03adς ανατομικ\u03adς μελ\u03adτες διαπιστ\u03ceθηκε \u03ccτι τα κ\u03cdτταρα αυτ\u03ac \u03adτειναν να \u03adχουν κυλινδρικ\u03ac \u03ae κωνικ\u03ac σχ\u03aeματα.<\/o:p><\/font><\/span><\/span><\/p>\n

Στην πραγματικ\u03ccτητα οι περισσ\u03ccτεροι αυτο\u03af φωτο\u03cbποδοχε\u03afς ε\u03afναι δ\u03cdσκολο να ταξινομηθο\u03cdν απ\u03cc την σχηματικ\u03ae μορφ\u03ae τους η οπο\u03afα αλλ\u03acζει αν\u03acλογα με την δι\u03acταξ\u03ae τους στον αμφιβληστροειδ\u03ae.<\/o:p><\/font><\/span><\/span><\/p>\n

Και οι δ\u03cdο τ\u03cdποι κυττ\u03acρων \u03adχουν ουσιαστικ\u03ac την \u03afδια δομ\u03ae. Το κυτταρικ\u03cc σ\u03ceμα περι\u03adχει τον πυρ\u03aeνα ο οπο\u03afος στηρ\u03afζει \u03adνα εξωτερικ\u03cc τμ\u03aeμα που περι\u03adχει περ\u03afπου 1000 ξεχωριστ\u03ac στρ\u03ceματα μορ\u03afων λ\u03afπους.<\/o:p><\/span><\/font><\/span><\/span><\/p>\n

Σε κ\u03acθε στρ\u03ceμα ε\u03afναι ενσωματωμ\u03adνα \u03adως 10.000 φωτοευα\u03afσθητα μ\u03ccρια φωτοχρωστικ\u03aeς ουσ\u03afας, της οψ\u03afνης. Η οψ\u03afνη των ραβδ\u03afων λ\u03adγεται ροδοψ\u03afνη, εν\u03ce η παραλλαγ\u03ae της που λειτουργε\u03af εντ\u03ccς των κων\u03afων καλε\u03afται ιωδοψ\u03afνη.<\/o:p><\/font><\/span><\/span><\/p>\n

\u038cταν το φως ερεθ\u03afζει την χρωστικ\u03ae, διακ\u03ccπτεται η συνοχ\u03ae της και τ\u03ccτε δημιουργε\u03af ηλεκτρικ\u03adς ωθ\u03aeσεις που αποστ\u03adλλονται στο συναπτικ\u03cc νευρωνικ\u03cc δ\u03afκτυο του αμφιβληστροειδο\u03cdς χιτ\u03ceνα.<\/font><\/span><\/span><\/p>\n

\u0388τσι, με τις ηλεκτρικ\u03adς αυτ\u03adς ωθ\u03aeσεις, πραγματοποιε\u03afται η λειτουργ\u03afα της \u03ccρασης. Οι μεν ωθ\u03aeσεις που προκαλο\u03cdνται απ\u03cc την δι\u03acσπαση της ροδοψ\u03afνης των ραβδ\u03afων ε\u03afναι υπε\u03cdθυνες για την αντ\u03afληψη του φωτ\u03ccς, οι δε ωθ\u03aeσεις που προκαλο\u03cdνται απ\u03cc την δι\u03acσπαση της ιωδοψ\u03afνης των κων\u03afων ευθ\u03cdνονται για την αντ\u03afληψη των χρωμ\u03acτων.<\/span><\/font><\/span><\/span><\/p>\n

Τα κων\u03afα χωρ\u03afζονται σε τρεις κατηγορ\u03afες. Αυτ\u03ac που αντιλαμβ\u03acνονται την κ\u03ccκκινη ακτινοβολ\u03afα, αυτ\u03ac που λειτουργο\u03cdν με την επ\u03afδραση της πρ\u03acσινης ακτινοβολ\u03afας και αυτ\u03ac που ερεθ\u03afζονται απ\u03cc την μπλε. <\/span><\/font><\/span><\/span><\/p>\n

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Translation into English<\/o:p><\/font><\/font><\/span><\/u><\/span><\/p>\n

Rods and cones<\/span><\/u><\/span> <\/span><\/span><\/font><\/font><\/p>\n



\n<\/span>Yes, the eye, the eye is primarily responsible for the operation of vision, but the key to the implementation of this are the tiny rods and cones. <\/span><\/span>Without them, the eye is unable to perform its intended purpose! <\/span><\/span><\/font><\/font>
\nThe function of vision depends on light-sensitive cells in the retina, the cones and rods. <\/font><\/span><\/span>
\nThese photoreceptors are the most complex sensory cells that we have and are divided into two types: <\/span>
\nA) the rods, around 120 – 140 million bar shaped cells adapted for the perception of dim light and night vision. <\/span>
\nB) the cones, about 6 – 7 million cone shaped cells, adapted to perceive the brightness of daylight and to analyze it in colors. <\/span><\/font><\/font><\/span>The cones are separated into three spectral types or classes of case. <\/span>
\nThe names, rods and cones, were given to these photoreceptors when the original anatomical studies found that these cells tended to have a cylindrical or conical shape. <\/span><\/span><\/font><\/font>
\nIn fact most of these photoreceptors are difficult to be classified on their schematic form that changes depending on their position in the retina. <\/span>
\n<\/font><\/font><\/span>Both cell types have essentially the same structure. The cell body contains the nucleus, which supports an outer portion that contains approximately 1,000 individual layers of fat molecules. <\/span><\/font><\/font><\/span>
\nIn each layer there are built up to 10,000 light-sensitive molecules of photo pigment substance, the opsin. The opsin of the rods is called rhodopsin and its variation operating within the cones is called iodopsin.<\/span>
\nWhen light stimulates the photo pigment, it suspends its consistency and then generates electrical impulses sent to the synaptic neuronal network of the retina. <\/span>
\n<\/font><\/font><\/span>Thus, the electrical impulses are functioning operation of vision. The impulses caused by the disruption of the rhodopsin of the rods are responsible for the perception of light, and the impulses generated by the decomposition of the cone’s iodopsin are responsible for color vision. <\/span><\/font><\/font><\/span>
\n<\/span>The cones are separated into three categories: Those that perceive the red radiation, those that are operating under the influence of green radiation and those that are stimulated by the blue one.<\/o:p><\/span><\/font><\/font><\/span><\/span><\/p>\n

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Ραβδ\u03afα και κων\u03afα   Ναι, ο οφθαλμ\u03ccς, το μ\u03acτι, ε\u03afναι ο κ\u03cdριος υπε\u03cdθυνος για την λειτουργ\u03afα της \u03ccρασης, \u03ccμως βασικο\u03af παρ\u03acγοντες για την εκτ\u03adλεση της λειτουργ\u03afας αυτ\u03aeς ε\u03afναι τα μικροσκοπικ\u03ac ραβδ\u03afα και κων\u03afα. Χωρ\u03afς αυτ\u03ac, το μ\u03acτι αδυνατε\u03af να εκτελ\u03adσει τον προορισμ\u03cc του!     Η λειτουργ\u03afα της \u03ccρασης εξαρτ\u03acται απ\u03cc τα φωτοευα\u03afσθητα κ\u03cdτταρα του […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20],"tags":[35,304,334,68,39,36,55,313,333,57,303,306],"class_list":["post-1373","post","type-post","status-publish","format-standard","hentry","category-leitourgies-orasis-xromatwn","tag-aktinovolia","tag-304","tag-334","tag-68","tag-konia","tag-mati","tag-ble","tag-313","tag-333","tag-prasino","tag-303","tag-306"],"_links":{"self":[{"href":"https:\/\/xromata.com\/index.php?rest_route=\/wp\/v2\/posts\/1373","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xromata.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/xromata.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/xromata.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/xromata.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1373"}],"version-history":[{"count":12,"href":"https:\/\/xromata.com\/index.php?rest_route=\/wp\/v2\/posts\/1373\/revisions"}],"predecessor-version":[{"id":6115,"href":"https:\/\/xromata.com\/index.php?rest_route=\/wp\/v2\/posts\/1373\/revisions\/6115"}],"wp:attachment":[{"href":"https:\/\/xromata.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1373"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xromata.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1373"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xromata.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1373"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}