Answer to Question 1
filtration
Rationale: Filtration serves to remove the lower energy radiation from the emerging beam to prevent it from reaching the patient.
Answer to Question 2
dolicocephalic
Rationale: A mesocephalic skull is a head shape that is proportional in its AP and lateral dimensions. A dolicocephalic head is longer front to back and narrow across. Brachycephalic head shape is described as round.