It’s a big week for made-for-TV movies about sex, greed, terror, all the usual stuff. But one of the movies, Silence of the Heart, about a teenager’s suicide, is the product of two big and beneficial trends on the tube: movies made to illuminate serious, sad issues, and movies starring actors willing to make themselves look like hell for their roles. Consider Farrah Fawcett, battered in The Burning Bed, Jane Fonda, poor and pudgy in The Dollmaker and James Garner, sick enough to die in Heartsounds. Now Mariette Hartley and Howard Hesseman let themselves look like leftover death as they grieve for their son in Silence. Looking awful is nothing new in movies, but it is new on TV. As for issues: The Burning Bed tried to teach us about wife abuse, Adam about missing children, Something About Amelia about incest, Heartsounds about doctors with sterile souls. These movies, educating us about the problems of the day, fill a need that used to be taken care of by sitcoms: Norman Lear’s All in the Family, Maude, One Day at a Time, et al. It’s a necessary job and one that fits well on TV, for who wants to pay $5 to go to a theater and see movies on these subjects? On TV, we’ll watch them, and in big numbers: The Burning Bed was the fifth highest rated TV movie ever. There is danger in such ratings, if TV tries too hard for tears. But what we have so far is a series of fine, responsible movies that have their place on the airwaves alongside simple entertainment, the novocaine for the brain that dominates much of the schedule this week.