The brain is made up of billions of cells, of which two types are the most common: neurons and glia cells. Neurons are the specialized nerve cells that are responsible for brain functions like thinking. The brain can be seen as a network of neurons, which are nourished, protected and supported by glia cells. All physical and mental functioning depends on the establishment and maintenance of neural networks. A person’s habits and skills become embedded within the brain in frequently activated neural connections.
The thought processes are actually electrical impulses: an impulse at one end of a neuron triggers the production of neurotransmitters, which are released at the other end into a space shared by other neurons. Neurons communicate not only with thousands of other neurons, but also with other tissues such as muscles, skin and digestive organs. Part of the high metabolic needs of the brain is from the energy needed to keep the electrical impulses firing.
Different brain functions are localized into specific sections of the brain. The largest part (“cerebrum”) controls language, speech, emotions, voluntary movement, and is the place where memories are stored and processed as well as where calculations are done. In addition, it comprehends sounds and images, and generates music and art. The “brain stem” connects the cerebrum with the spinal cord. It regulates critical body functions like breathing, swallowing, blood pressure, heartbeat and pulse rate, digestion and posture. Movement and coordination start in the “cerebellum,” which also stores memories of practiced movements. Memory formation occurs in the “hippocampus.” This part of the brain continues to produce nerve cells even during adulthood.