Question

Bundles of nerve fibers running through the CNS are called ______, whereas in the PNS they are called ____.

Answer 1

In the CNS, bundles of nerve fibers are called tracts, while in the PNS they are called nerves. An example is the optic nerve in the PNS and the optic tract in the CNS.

Step-by-step explanation:

In the Central Nervous System (CNS), bundles of nerve fibers are called **tracts**. In the Peripheral Nervous System (PNS), they are called **nerves**. It's important to note that the same bundle of axons can be referred to as a nerve in the PNS and a tract in the CNS. For example, the axons that project from the retina into the brain are called the **optic nerve** in the PNS and the **optic tract** in the CNS. This change in name occurs at a specific point called the **optic chiasm**.