Final answer:
Naegleria fowleri enters the CNS by traveling along the olfactory or trigeminal cranial nerves.
Step-by-step explanation:
The brain-eating amoeba, Naegleria fowleri, enters the central nervous system (CNS) by traveling along the olfactory or trigeminal cranial nerves. These nerves are responsible for the sense of smell and transmit information from the nasal passages to the brain. The amoeba initially enters through the nasal passages, reaches the sinuses, and then moves along these cranial nerves to reach the subarachnoid space in the CNS.