People shouldn't gross out their friends with surgical pictures.
Paul is studying human anatomy with his friends.
Paul wants to share what he's learning.
Paul explains the material in his notes to his friends.
Paul points out the parts of the arm by showing them pictures of the arm he dissected during lab.
Paul's knowledge impresses his friends who ask him questions whenever they need medical advice.
Paul's friends quietly excuse themselves leaving Paul alone for the rest of the evening.