Carm, have a look at Galatians 1, near the end of the chapter, where Paul is describing how he received the gospel directly from Jesus, ie. through a vision or some other form of direct communication;

"nor did I go up to Jerusalem to the apostles who came before me, but I went into Arabia and later returned to Damascus. Only after three years did I go up to Jerusalem to confer with Cephas, and I stayed with him fifteen days. But I saw none of the other apostles except James, the Lord’s brother.…"

The word (translated brother) used here in the original koine Greek is; "adelphos"
Literally meaning  "from the same womb". Breaking it down; "a" = from, "delphos" = womb.

Please see here for a more detailed discussion of the Greek;
http://biblehub.com/greek/80.htm