fix questions

anatomy/models.py

@@ -37,10 +37,10 @@ class BodyPart(models.Model):
 
 
 class Structure(models.Model):
-    bodypart = models.CharField(max_length=200)
+    structure = models.CharField(max_length=200)
 
     def __str__(self):
-        return self.bodypart
+        return self.structure
 
 
 class Modality(models.Model):
@@ -193,7 +193,7 @@ class Answer(models.Model):
 class Exam(models.Model):
     name = models.CharField(max_length=200)
     exam_questions = models.ManyToManyField(AnatomyQuestion,
-                                            related_name="exams")
+                                            related_name="exams", blank="true")
 
     active = models.BooleanField(help_text="If an exam should be available",
                                  default=True)