When Penis is a Bad Word

I caught this preview clip of the Oprah show that is set to air today, and was surprised to see that the word penis is bleeped out as though it is a swear word. Since when did names for our body parts become vulgar? It will be interesting to see if penis is bleeped out during the entirety of the show, and would certainly send the wrong message to young viewers in that it makes naming genitalia somehow shameful and dirty by the omission of the word.
Also, this is the only preview clip of the show that is up – notice that it is focused on the penis of Lorena’s husband, and not the events that led up to what caused her to cut off his genitalia.