aksoniin

Aksoniin (Finnish for axon) is the elongated projection of a neuron that conducts electrical impulses away from the cell body toward synapses. The axon typically originates at the axon hillock, a specialized region near the soma, and ends at synaptic terminals where signals are transmitted to other neurons or effector cells. Axons transmit signals through action potentials, all-or-nothing electrical impulses that propagate along the axon membrane.

Internally, the axon contains cytoskeletal elements such as microtubules that support transport and structure. A key feature of many axons is myelination, where insulating glial cells form a myelin sheath around the axon. In the central nervous system, myelin is produced by oligodendrocytes; in the peripheral nervous system, Schwann cells provide insulation. Gaps in the myelin sheath, called nodes of Ranvier, enable saltatory conduction, which increases the speed of signal transmission.

Axonal transport moves cellular components between the soma and the terminals. Anterograde transport, directed away from the soma, uses kinesin motors to deliver vesicles and organelles; retrograde transport, moving toward the soma, uses dynein motors. This transport system is essential for maintaining axon function and signaling.

Axon structure and function vary among neurons; some have long, unbranched axons, while others branch extensively to contact multiple targets. Regeneration after injury is limited in the central nervous system but more robust in the peripheral nervous system, where glial cells and growth factors support repair. Dysfunction or injury of aksoniin underlies many neurological disorders, including neuropathies and neurodegenerative diseases, highlighting its central role in neural communication and nerve health.