Description
Neurons are the functional units of the nervous system.
- They are one of the most active cell groups in our body -- consuming a lot of energy (the brain uses up to 20% of daily energy usage) in the form of glycogen, however, they do not store it.
- Neurons have the characteristics of protein-producing cells, therefore, their nucleus is euchromatic and they contain a lot of ribosomes -- both free and bound to rER.
- Usually, a large nucleolus will also be visible.
- Neurons cannot divide, however, in some areas of the brain, neuronal stem cells are capable of replacing damaged cells.
Parts
- The cell body is the major part of the neuron, containing basophilic aggregations called Nissl bodies that are clusters of ribosomes in the rER.
- Extending from the cell body there are several processes that usually include one or more dendrites and a single axon that forms a synapse at its end.