Sexual Discrimination

You can abuse people in English by referring to them as a sexual organ, though only in the vernacular: calling someone a vagina or a penis will have little impact. The choice between characterizing them as either male or female genetalia does carry significance, however.
Should you choose male abuse, this will reflect on the target's perceived lack of intelligence: a cock or a prick is a stupid person. When choosing a female equivalent, you confirm the target's calculated malevolence: a cunt.
Note that this figurative language seems to apply to these organs specifically. Being a dick is quite different to having balls, while other female organs do not have the same connotations: e.g. a tit (though this may because it is in the singular, as in a camel short of a caravan).
If you doubted that sexual politics and language were interrelated, the above should encourage you to reconsider, you twat.