The diagram shows a gap junction and its main element. connexon. together with the structure of the connexin.
Mariana Ruiz <a href="//commons.wikimedia.org/wiki/User:LadyofHats" title="User:LadyofHats">LadyofHats</a>
the diagram i made myself using the information found on this website: <a class="external autonumber" href="https://de.wikipedia.org/wiki/Bild:Connexin.png">[1]</a>, <a rel="nofollow" class="external autonumber" href="http://www.unmc.edu/dept/biochemistry/index.cfm?L1_ID=13&amp;CONREF=18">[2]</a>  ,<a rel="nofollow" class="external text" href="http://herkules.oulu.fi/"></a><a href="//commons.wikimedia.org/wiki/Special:BookSources/9514259351" title="Special:BookSources/9514259351">ISBN 9514259351</a>/html/i245454.html , <a rel="nofollow" class="external autonumber" href="http://www.rhul.ac.uk/biological-sciences/AcademicStaff/Duden/">[3]</a> ,<a rel="nofollow" class="external autonumber" href="http://www.nature.com/ng/journal/v20/n4/fig_tab/ng1298_319_F2.html">[4]</a> ,and  <a rel="nofollow" class="external autonumber" href="http://www.lrz-muenchen.de/~jmd/seminar_woche_6.htm">[5]</a> the diagram is made with adobe illustrator.