Description
A nerve cell, or neuron, is a specialized cell of the nervous system responsible for receiving, processing, and transmitting electrical and chemical signals throughout the body. Neurons form the structural and functional basis of communication in the brain, spinal cord, and peripheral nerves.
Structure of a Nerve Cell
Cell Body (Soma): Contains the nucleus and most of the cell's organelles. It is responsible for maintaining the neuron's health and metabolic activities.
Dendrites: Branch-like extensions from the cell body that receive incoming signals from other neurons. They conduct these electrical impulses toward the cell body, allowing integration of information from multiple sources.
Axon: A single, elongated projection from the cell body that transmits electrical impulses away from the neuron to other cells (neurons, muscles, or glands). The axon may be covered in a myelin sheath, a fatty insulating layer that speeds up signal transmission.
Axon Hillock: The region where the axon joins the cell body and where action potentials (nerve impulses) typically originate.
Axon Terminals (Synaptic Boutons): The branched endpoints of the axon, where the neuron communicates with other cells by releasing neurotransmitters across synapses.
Myelin Sheath: An insulating layer around many axons, produced by oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system. It allows for rapid conduction of nerve impulses.
Nodes of Ranvier: Gaps in the myelin sheath that facilitate the rapid transmission of nerve impulses via saltatory conduction.
Function
Neurons receive signals through dendrites, process those signals in the cell body, and carry outgoing electrical impulses along the axon to synapses, where the signal is transmitted to other neurons or effectors via neurotransmitters. This enables everything from sensory perception and movement to cognition and reflex responses.