<li class="dropdown">
  <a href="#" class="dropdown-toggle account-dropdown" data-toggle="dropdown">Account <span class="caret"></span></a>
  <ul class="dropdown-menu" role="menu">
    <li><%= link_to "My Page", user_path(current_user) %></li>
    <li><%= link_to "My Settings", edit_user_registration_path(current_user) %></li>
    <li><%= link_to 'Sign out', destroy_user_session_path, :method => :delete %></li>
  </ul>
</li>

<li class="dropdown">
  <a href="#" class="dropdown-toggle account-dropdown" data-toggle="dropdown">Account <span class="caret"></span></a>
  <ul class="dropdown-menu" role="menu">
    <li><%= link_to "My Page", user_path(current_user) %></li>
    <li><%= link_to "My Settings", edit_user_registration_path(current_user) %></li>
    <% if current_user.admin? %>
      <li><%= link_to "Articles", articles_path %></li>
    <% end %>
    <li><%= link_to 'Sign out', destroy_user_session_path, :method => :delete %></li>
  </ul>
</li>

Add articles option to menu for admins
Add articles option to menu for admins
