Final answer:
The principal parts of a neuron include the cell body, dendrites, and axon. The cell body houses the nucleus and organelles, dendrites receive signals, and the axon carries impulses away and communicates with other cells through the synapse.
Step-by-step explanation:
The three principal parts of a nerve cell, also known as a neuron, are:
- The cell body, which contains the nucleus and various organelles necessary for the cell's function.
- Dendrites, which are extensions from the cell body that receive nerve impulses from other neurons.
- The axon, a long projection that transmits nerve impulses to other cells and ends in axon terminals, the points of communication with other cells.
The cell body is the neuron's core, supporting cell life functions with the nucleus and organelles. Dendrites branch out from the cell body, resembling thin extensions, to receive incoming signals. The axon is the neuron's elongated tail, carrying electrical impulses away from the neuron. At its end, the axon may be ensheathed in myelin, an insulating substance produced by accessory cells.
Neurons communicate with each other or with target cells (like muscles or glands) at a junction known as the synapse. Here, neurotransmitters carry the impulse across this gap. Neurons come in several forms, including multipolar, bipolar, and unipolar, depending on the number and arrangement of dendrites and axons.