A university public health professor in the United States has had to defend her curriculum after a student complained she showed a pornographic film in class.

Fresno State University professor Peggy Gish showed her class a 20 minute adult film, Advanced Sexual Techniques, Volume One, which contained sexually explicit audio and graphic video, reported Campus Reform.

In a statement to The Huffington Post, Fresno College dean Andrew Hoff defended Gish, explaining that the video segment was part of a semester-long human sexuality education course. The class explores "physiological, psychological, social, cultural and developmental considerations for life-long understanding related to sexuality," he said.

"It is not a required course. Students who take the course are advised, in advance, that they may find some content objectionable and that they may opt out at their discretion," he said.