What constitutes the basic unit of the nervous system?

The basic unit of the nervous system is the neuron. Neurons are specialized cells responsible for transmitting information throughout the nervous system via electrical and chemical signals. This is fundamental to the functioning of the brain and the entire nervous system, enabling processes such as sensation, thought, movement, and the coordination of bodily functions.

Neurons are unique in their structure, equipped with dendrites to receive signals from other neurons, a cell body that processes this information, and an axon that sends signals to other neurons or target cells. This intricate design allows for complex communication networks within the nervous system.

While glial cells play supportive roles, such as maintaining homeostasis, forming myelin, and providing protection and support for neurons, they do not transmit signals in the way that neurons do. Synapses are the connections between neurons where communication occurs, but they are not units themselves—they depend on the presence of neurons to function. Plasma cells, which are derived from B lymphocytes and produce antibodies, are part of the immune system and unrelated to the structural and functional organization of the nervous system. Thus, neurons are rightly recognized as the fundamental units that enable the entire structure and functionality of the nervous system.