{"id":{"repo_id":"greece","oai_identifier":"oai:10442/1393"},"canonical_url":"https://search.dev.ndltd.org/etd/greece/oai:10442/1393","repository":{"repo_id":"greece","name":"Greek National Archive of PhD Theses","base_url":"https://phdtheses.ekt.gr/eadd_oai/request"},"display":{"title":"Ηλεκτρονική μικροσκοπία της ανθρώπινης επίφυσης (κωναρίου): Συγκριτική μελέτη στις διάφορες ηλικίες","abstract":"With the exception of one study of embryonic tissue, there is no reference in the literature concerning the ultrastructure of human pineal. In this work we present the results of a study of 24 human pineals from individuals aged 4-75 years. The material was obtained from autopsies which were performed 45-240 minutes following death. The main cellular element of the human pineal is the pineocyte but glial cells as well as nerve fibers were also identified. Tight junctions were identified between the capillary endothelial cells. The ultrastructure of the human pineocyte is similar to that of the pineocytes of other mammalian species. In particular we proved the presence of some organelles which are unique to the pineal (e.g. synaptic spherules, microtubular sheaves) or characteristic for the pineocyte and a few other cell types (e.g. synaptic ribbons). These organelles were not described in the human embryonic pineal. The function of microtubular sheaves is not known but it is believed that they are derived from centrioles. Our results support this view. Synaptic spherules have been described in only a few other mammalian species (e.g. guinea pig, rabbit). Our study indicates that these organelles are more often encountered in the human pineocyte than the synaptic ribbons. Their function and relation to the synaptic ribbons is disputed but they are generally believed to be distinct from the latter and to be involved in the secretory function of the pineal. Our study supports both these views. Synaptic ribbons were similar to those described in other mammalian and submammalian species.","abstract_html":"With the exception of one study of embryonic tissue, there is no reference in the literature concerning the ultrastructure of human pineal. In this work we present the results of a study of 24 human pineals from individuals aged 4-75 years. The material was obtained from autopsies which were performed 45-240 minutes following death. The main cellular element of the human pineal is the pineocyte but glial cells as well as nerve fibers were also identified. Tight junctions were identified between the capillary endothelial cells. The ultrastructure of the human pineocyte is similar to that of the pineocytes of other mammalian species. In particular we proved the presence of some organelles which are unique to the pineal (e.g. synaptic spherules, microtubular sheaves) or characteristic for the pineocyte and a few other cell types (e.g. synaptic ribbons). These organelles were not described in the human embryonic pineal. The function of microtubular sheaves is not known but it is believed that they are derived from centrioles. Our results support this view. Synaptic spherules have been described in only a few other mammalian species (e.g. guinea pig, rabbit). Our study indicates that these organelles are more often encountered in the human pineocyte than the synaptic ribbons. Their function and relation to the synaptic ribbons is disputed but they are generally believed to be distinct from the latter and to be involved in the secretory function of the pineal. Our study supports both these views. Synaptic ribbons were similar to those described in other mammalian and submammalian species.","abstract_has_math":false,"creators":["Petrou, Georgios","Πέτρου, Γεώργιος"],"institution":"University of Patras","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1990,"date_issued":"1990","date_published":"1990","updated_at":"2026-07-24T02:24:52Z","subjects":["Εγκεφαλική επίφυση","Επιφυσιοκύτταρο","Ηλεκτρονική μικροσκοπίας της ανθρώπινης επίφυσης","Κωνάριο","Μικροσωληνώδη δεμάτια","Συναπτικά σφαιρίδια","Συναπτικές ταινίες","Epiphysis cerebri","Human pineal gland","Microtubular sheaves","Pineocyte","Synaptic ribbons","Synaptic spherules","Ultrastructure of the human pineal gland","Ιατρική και Επιστήμες Υγείας","Βασική Ιατρική","Medical and Health Sciences","Basic Medicine"],"languages":["gre"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["10.12681/eadd/1393"],"render_values":[{"text":"10.12681/eadd/1393","href":"https://doi.org/10.12681/eadd/1393","code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10442/hedi/1393","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Petrou, Georgios","Πέτρου, Γεώργιος"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["1990"]},{"key":"dc:publisher","label":"Institution","values":["University of Patras","Πανεπιστήμιο Πατρών"]},{"key":"dc:type","label":"Dc Type","values":["PhD Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Εγκεφαλική επίφυση","Επιφυσιοκύτταρο","Ηλεκτρονική μικροσκοπίας της ανθρώπινης επίφυσης","Κωνάριο","Μικροσωληνώδη δεμάτια","Συναπτικά σφαιρίδια","Συναπτικές ταινίες","Epiphysis cerebri","Human pineal gland","Microtubular sheaves","Pineocyte","Synaptic ribbons","Synaptic spherules","Ultrastructure of the human pineal gland","Ιατρική και Επιστήμες Υγείας","Βασική Ιατρική","Medical and Health Sciences","Basic Medicine"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["gre"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["10.12681/eadd/1393","http://hdl.handle.net/10442/hedi/1393"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["With the exception of one study of embryonic tissue, there is no reference in the literature concerning the ultrastructure of human pineal. In this work we present the results of a study of 24 human pineals from individuals aged 4-75 years. The material was obtained from autopsies which were performed 45-240 minutes following death. The main cellular element of the human pineal is the pineocyte but glial cells as well as nerve fibers were also identified. Tight junctions were identified between the capillary endothelial cells. The ultrastructure of the human pineocyte is similar to that of the pineocytes of other mammalian species. In particular we proved the presence of some organelles which are unique to the pineal (e.g. synaptic spherules, microtubular sheaves) or characteristic for the pineocyte and a few other cell types (e.g. synaptic ribbons). These organelles were not described in the human embryonic pineal. The function of microtubular sheaves is not known but it is believed that they are derived from centrioles. Our results support this view. Synaptic spherules have been described in only a few other mammalian species (e.g. guinea pig, rabbit). Our study indicates that these organelles are more often encountered in the human pineocyte than the synaptic ribbons. Their function and relation to the synaptic ribbons is disputed but they are generally believed to be distinct from the latter and to be involved in the secretory function of the pineal. Our study supports both these views. Synaptic ribbons were similar to those described in other mammalian and submammalian species.","Με την εξαίρεση μιας μελέτης εμβρυϊκών επιφύσεων στη βιβλιογραφία δεν υπάρχει, αναφορά σχετική με την υπερμικροσκοπική υφή της επίφυσης του ανθρώπου. Στη εργασία αυτή περιγράφονται τα αποτελέσματα της μελέτης 24 επιφύσεων από άτομα ηλικίας 4-75 ετών. Το υλικό προήλθε από νεκροτομές που έγιναν 45-240 λεπτά μετά το θάνατο. Το κύριο κυτταρικό στοιχείο ήταν το επιφυσιοκύτταρο, αλλά διαπιστώθηκε επίσης η παρουσία γλοιακών κυττάρων και νευρικών ινών. Τα ενδοαηλιακά κύτταρα των τριχοειδών συνδέονται με αποφρακτικές ζώνες, δομές που υποδηλώνουν την ύπαρξη αιματοεγκεφαλικού φραγμού. Η υπερμικροσκοπική υφή του επιφυσιοκυττάρου παρουσιάζει ομοιότητες με αυτή των επιφυσιοκυττάρων άλλων θηλαστικών. Ειδικότερα διαπιστώθηκε η παρουσία ορισμένων οργανιδίων που θεωρούνται μοναδικά για την επίφυση (συναπτικά σφαιρίδια, μικροσωληνώδη δεμάτια) ή χαρακτηριστικά για τα επιφυσιοκύτταρα και μερικά άλλα είδη κυττάρων (συναπτικές ταινίες). Αυτά τα οργανίδια δεν παρατηρήθησαν στα επιφυσιοκύτταρα του εμβρύου. Η λειτουργία των μικροσωληνωδών δεματίων δεν είναι γνωστή. Πιστεύεται ότι προέρχονται από τα κεντριόλια και τα αποτελέσματα μας στηρίζουν την άποψη αυτή. Τα συνοπτικά σφαιρίδια έχουν περιγραφεί μόνο σε λίγα είδη θηλαστικών, και σε μικρούς αριθμούς. Η μελέτη μας έδειξε ότι στα επιφυσιοκύτταρα του ανθρώπου τα οργανίδια αυτά είναι πολυάριθμα και συναντώνται σαφώς συχνότερα από ό,τι οι συναπτικές ταινίες. Η πιθανή λειτουργία των συναπτικών ταινιών είναι ότι ενέχονται στην επικοινωνία μεταξύ των κυττάρων και ότι λειτουργούν ως υποδοχείς για τους συμπαθητικούς νευροδιαβιβαστές. Επίσης έχει προταθεί ότι μπορεί να ενέχονται στη σύνθεση και την αποθήκευση της μελατονίνης, του κυρίου εκκριτικού προϊόντος των επιφυσιοκυττάρων. Συμπερασματικά, τα επιφυσιοκύτταρα του ανθρώπου εμφανίζουν σαφείς ομοιότητες με τα επιφυσιοκύτταρα άλλων θηλαστικών. Ιδιαίτερο ενδιαφέρον παρουσιάζει ο σχετικά μεγάλος αριθμός των συνοπτικών σφαιριδίων στα επιφυσιοκύτταρα του ανθρώπου. Η μελέτη μας παρέχει κάποιες ενδείξεις ότι τα συναπτικά σφαιρίδια συμμετέχουν σε εκκριτικούς μηχανισμούς του επιφυσιοκυττάρου στον άνθρωπο."]},{"key":"dc:title","label":"Title","values":["Ηλεκτρονική μικροσκοπία της ανθρώπινης επίφυσης (κωναρίου): Συγκριτική μελέτη στις διάφορες ηλικίες","Ultrastructure of the human pineal gland"]}]}],"canonical_facts":{"dc:creator":["Petrou, Georgios","Πέτρου, Γεώργιος"],"dc:date":["1990"],"dc:description":["With the exception of one study of embryonic tissue, there is no reference in the literature concerning the ultrastructure of human pineal. In this work we present the results of a study of 24 human pineals from individuals aged 4-75 years. The material was obtained from autopsies which were performed 45-240 minutes following death. The main cellular element of the human pineal is the pineocyte but glial cells as well as nerve fibers were also identified. Tight junctions were identified between the capillary endothelial cells. The ultrastructure of the human pineocyte is similar to that of the pineocytes of other mammalian species. In particular we proved the presence of some organelles which are unique to the pineal (e.g. synaptic spherules, microtubular sheaves) or characteristic for the pineocyte and a few other cell types (e.g. synaptic ribbons). These organelles were not described in the human embryonic pineal. The function of microtubular sheaves is not known but it is believed that they are derived from centrioles. Our results support this view. Synaptic spherules have been described in only a few other mammalian species (e.g. guinea pig, rabbit). Our study indicates that these organelles are more often encountered in the human pineocyte than the synaptic ribbons. Their function and relation to the synaptic ribbons is disputed but they are generally believed to be distinct from the latter and to be involved in the secretory function of the pineal. Our study supports both these views. Synaptic ribbons were similar to those described in other mammalian and submammalian species.","Με την εξαίρεση μιας μελέτης εμβρυϊκών επιφύσεων στη βιβλιογραφία δεν υπάρχει, αναφορά σχετική με την υπερμικροσκοπική υφή της επίφυσης του ανθρώπου. Στη εργασία αυτή περιγράφονται τα αποτελέσματα της μελέτης 24 επιφύσεων από άτομα ηλικίας 4-75 ετών. Το υλικό προήλθε από νεκροτομές που έγιναν 45-240 λεπτά μετά το θάνατο. Το κύριο κυτταρικό στοιχείο ήταν το επιφυσιοκύτταρο, αλλά διαπιστώθηκε επίσης η παρουσία γλοιακών κυττάρων και νευρικών ινών. Τα ενδοαηλιακά κύτταρα των τριχοειδών συνδέονται με αποφρακτικές ζώνες, δομές που υποδηλώνουν την ύπαρξη αιματοεγκεφαλικού φραγμού. Η υπερμικροσκοπική υφή του επιφυσιοκυττάρου παρουσιάζει ομοιότητες με αυτή των επιφυσιοκυττάρων άλλων θηλαστικών. Ειδικότερα διαπιστώθηκε η παρουσία ορισμένων οργανιδίων που θεωρούνται μοναδικά για την επίφυση (συναπτικά σφαιρίδια, μικροσωληνώδη δεμάτια) ή χαρακτηριστικά για τα επιφυσιοκύτταρα και μερικά άλλα είδη κυττάρων (συναπτικές ταινίες). Αυτά τα οργανίδια δεν παρατηρήθησαν στα επιφυσιοκύτταρα του εμβρύου. Η λειτουργία των μικροσωληνωδών δεματίων δεν είναι γνωστή. Πιστεύεται ότι προέρχονται από τα κεντριόλια και τα αποτελέσματα μας στηρίζουν την άποψη αυτή. Τα συνοπτικά σφαιρίδια έχουν περιγραφεί μόνο σε λίγα είδη θηλαστικών, και σε μικρούς αριθμούς. Η μελέτη μας έδειξε ότι στα επιφυσιοκύτταρα του ανθρώπου τα οργανίδια αυτά είναι πολυάριθμα και συναντώνται σαφώς συχνότερα από ό,τι οι συναπτικές ταινίες. Η πιθανή λειτουργία των συναπτικών ταινιών είναι ότι ενέχονται στην επικοινωνία μεταξύ των κυττάρων και ότι λειτουργούν ως υποδοχείς για τους συμπαθητικούς νευροδιαβιβαστές. Επίσης έχει προταθεί ότι μπορεί να ενέχονται στη σύνθεση και την αποθήκευση της μελατονίνης, του κυρίου εκκριτικού προϊόντος των επιφυσιοκυττάρων. Συμπερασματικά, τα επιφυσιοκύτταρα του ανθρώπου εμφανίζουν σαφείς ομοιότητες με τα επιφυσιοκύτταρα άλλων θηλαστικών. Ιδιαίτερο ενδιαφέρον παρουσιάζει ο σχετικά μεγάλος αριθμός των συνοπτικών σφαιριδίων στα επιφυσιοκύτταρα του ανθρώπου. Η μελέτη μας παρέχει κάποιες ενδείξεις ότι τα συναπτικά σφαιρίδια συμμετέχουν σε εκκριτικούς μηχανισμούς του επιφυσιοκυττάρου στον άνθρωπο."],"dc:identifier":["10.12681/eadd/1393","http://hdl.handle.net/10442/hedi/1393"],"dc:language":["gre"],"dc:publisher":["University of Patras","Πανεπιστήμιο Πατρών"],"dc:subject":["Εγκεφαλική επίφυση","Επιφυσιοκύτταρο","Ηλεκτρονική μικροσκοπίας της ανθρώπινης επίφυσης","Κωνάριο","Μικροσωληνώδη δεμάτια","Συναπτικά σφαιρίδια","Συναπτικές ταινίες","Epiphysis cerebri","Human pineal gland","Microtubular sheaves","Pineocyte","Synaptic ribbons","Synaptic spherules","Ultrastructure of the human pineal gland","Ιατρική και Επιστήμες Υγείας","Βασική Ιατρική","Medical and Health Sciences","Basic Medicine"],"dc:title":["Ηλεκτρονική μικροσκοπία της ανθρώπινης επίφυσης (κωναρίου): Συγκριτική μελέτη στις διάφορες ηλικίες","Ultrastructure of the human pineal gland"],"dc:type":["PhD Thesis"]},"updated_at":"2026-07-24T02:24:52Z"}