O neuron, the cell common to any nervous system in the Animalia kingdom, resembles, in its function, a conductor of electricity.
A typical neuron has three distinct parts: cell body, dendrites and axon.
- At the cell body, the bulkiest part of the nerve cell, are located the nucleus and most cytoplasmic structures.
- The dendrites (from Greek dendron, tree) are thin and usually branched extensions that drive the stimuli captured from the environment or from other cells towards the cell body.
- O axon It is a thin extension, usually longer than the dendrites, whose function is to transmit to the other cells the nerve impulses from the cell body.
The network of neurons
The neurons that make up the nervous system form an intricate network, comparable in some ways to the telephone system of a large city. The nerve network is formed by axons and dendrites, which act as nerve impulse transmission cables, and by neuron cell bodies, which act as processing and information transmission stations.
In vertebrates, cell bodies of neurons are concentrated in the central nervous system, ie in the brain and spinal cord, and also in small globular structures scattered throughout the body, the nerve ganglia. Dendrites and axons, often called nerve fibers, extend throughout the body, connecting neuron cell bodies to each other and to sensory, muscle, and glandular cells.
In vertebrates, in addition to neurons, the nervous system is made up of glial cells or glial cells. The function of these cells is to support the neurons and assist their functioning. Glial cells make up about half the volume of our brain.
There are several types of glial cells. The astrocytesFor example, they are arranged along the brain's blood capillaries, controlling the passage of substances in the blood to cells of the nervous system. The oligodendrocytes and the Schwann cells they wrap around the axons of certain neurons, forming insulating wraps.