What is the large mass of closely packed bundles of nerve cells?

The large mass of closely packed bundles of nerve cells is known as a nerve or neural tissue. In the context of the central nervous system, this refers to structures such as the brain and spinal cord, where neurons are densely packed to facilitate communication and processing of information. In peripheral nerves, bundles of axons (the long projections of nerve cells) are organized together within protective sheaths, enabling efficient signal transmission throughout the body.