Understanding the Brain: Structure, Function, and Complexity
The Brain: A Complex System
V.1. The brain works; much of the complexity lies in the diversity of cerebral structural, functional, and molecular characterization of neurons, coupled with its spectacular plasticity, i.e., the ability of neuronal synapses to weave new networks because of their own brain activity. In this inner universe in constant activity, Ramón y Cajal saw “the mysterious butterflies of the soul, whose flapping wings, who knows if someday will clarify the secret of mental life.”
Our brain is made up of roughly 1 trillion cells, of which about 100,000 million are neurons which weave a network of 100 trillion synaptic connections. The set of connections that each individual gets form will determine how your brain reacts to sensory information, how to generate emotional states, and how to plan their conduct. These connections will be implemented for religious beliefs, moral and scientific for each subject. When a group of individuals sharing a common design or a single neural map, then we say that these individuals belong to the same culture.
Basic Divisions of the Nervous System
A very basic description of the nervous system is usually divided into two groups or components:
- The peripheral nervous system, consisting of groups of neurons called ganglia and peripheral nerves that lie outside the spinal cord and brain.
- The central nervous system, consisting of the brain and spinal cord.
Both systems are anatomically separate but interconnected. Since it is in the central nervous system which produces the processing of information received through the peripheral systems, the central nervous system is divided into seven main regions:
Regions of the Central Nervous System
- The spinal cord extends from the skull base to the first lumbar vertebra. The spinal cord receives sensory information from the skin, joints, and muscles of the trunk and limbs; also, contains the motor neurons responsible for voluntary and involuntary movements.
- The medulla is an extension of the spinal cord and shares with it certain responsibilities. Involved in the regulation of blood pressure and respiration.
- The pons, located near the medulla oblongata, which form a large number of neurons that distribute information from the cerebral hemispheres to the cerebellum.
- The cerebellum receives sensory information from the spinal cord, motor information from the cortex, and information on the balance from the inner ear vestibular organs. The convergence of all of this information enables the cerebellum for coordination and planning of movements.
- The midbrain, above the pons, is involved in controlling eye movements and the movement of skeletal muscles. In turn, is a key relay station for auditory and visual signals.
- The diencephalon; it makes up the thalamus and hypothalamus. The thalamus processes and distributes all sensory and motor information that reaches the cerebral cortex. Apparently also involved in regulating the level of consciousness and emotional aspects of sensation.
- The hypothalamus has the task of regulating the autonomic nervous system and pituitary hormone secretion.
- Finally, the cerebral hemispheres. These two regions of the brain are composed of white matter, nuclei, consisting of a group of neurons that are functionally connected, forming the basal ganglia, the hippocampal formation, and amygdala, and cerebral cortex.