The lowdown on med school from a young (27) physician/writer (Recombinations; I Am Having An Adventure). Compiled from essays written while at Harvard Med School and published in the New York Times, Discover, and elsewhere, Klass' highly personalized, irreverent account proceeds chronologically, covering ""pre-clinical"" instruction (first year: classroom and lab), then ""clinical"" (second year: in-hospital). In addition to providing short, bemused pieces on two factors distinguishing her from many of her colleagues--being female, and becoming a mother while in reed school--Klass displays sharp commercial savvy in offering pieces that concentrate on the more sensational and secretive aspects of a physician's training: cadaver dissection (""The skin, after long soaking in formaldehyde, is quite leathery""); the thrills of surgery (""the bigger the operation, the more awesome the whomp, the more fun it is""); medical jargon (""Baseball metaphor is pervasive. A no-hitter is a night without any new admissions""); dangerous medical students (""007s--licensed to kill""). Following these arched-eyebrow reports, she examines ""Issues"": in essays predominantly serious or sentimental, she explores whether an M.D. should tell a child he might have AIDS; the morality of prescribing drugs with potentially dangerous side-effects; whether to resuscitate patients suffering from terminal, pain-wracked ailments; etc. Wrapping things up, Klass offers a long, self-sanctifying essay that points up the emotional and physical strain of internship by depicting a typically grueling weekend's rotations. An aura of smugness clings to Klass' self-appointed mission to lift the curtain on med school; still, this often funny, unusually frank expose' delivers the goods, with great panache.