Step 1 : Introduction to the question "4. A is for what part of the neurone that carries impulses away from the cell body?"
...1. Axon 2. Aneurysm 3. Aqueduct 4. Arachnoid Axons are usually coated in a white fatty substance called the myelin sheath which helps to speed the passage of impulses. They are sometimes called axones. An aqueduct is a canal or passage. There are two in the brain: the Sylvian aqueduct and the Cerebral aqueduct. The arachnoid is the delicate middle layer of the meninges. Its fine web-like appearance gives rise to its name. An aneurysm is a sac formed by a dilation in a vessel wall, usually an artery.