Neurons are nerve cells and the basic unit of the CNS (neurons are also the basic unit of the PNS). Each neuron has: 1.) a soma (body), 2.) dendrites (receive messages), and 3.) axons (send messages). Neurons are the building blocks of our brain along with the neurotransmitters and brain receptors. A half billion years ago we have the first nerve cells that coordinate movement. It was sea anemone and jellyfish that had the original nerve cells (another example of our tie to the Sea). In the pregnant female womb neurons are amazingly being created at the rate of 15 million per hour. That is, for 50 days after conception our embryonic brain goes through a massive explosion of neuronal growth where neurons are increasing by many millions per day. In infancy these nerve cells intertwine into various networks and by the age of four or five the fundamental brain structural networks are in place. The brain has approximately 100 billion neurons stretched through 100,000 miles of blood vessels. There are as many nerve cells as the 100 billion Stars in the Milky Way. Neuronal cells control senses, movement, thought, moods, and various behaviors. Each healthy neuron is linked to tens of thousands of other neurons.
Synapses – Each neuron has about 2,000 synapses. Synapses are the junction between neurons where messages are sent (axons), and messages are received (dendrites). Astonishingly, there is an estimated 100 trillion synapses in our brain. In the formation of synapses, the prefrontal brain is one of the last brain structures to stop forming synapses. For me, this explains some of the immaturity and impulsivity that still takes place for us in our late teens and early twenties. Dendrites are extensive bundles of nerve fiber with a huge number of branching connections (dendrite is from the Latin for “tree”). Dendrites receive micro messages coming from the axon when the synaptic junction is jumped. A neuronal axon transmits electro-chemical messages from neuron to neuron as rapidly as 1,000 impulses a second and somehow these electro-chemical messages allow for consciousness. Neuronic consciousness allows for awareness, comprehension, and useable knowledge (review CACK Model in previous posts).