The brain is a major part of the central nervous system. In vertebrates, the brain is connected to the spinal cord. In invertebrates' nervous systems, the brain can be a decentralized collection of neurons or a single ganglion. In the vertebrates, the brain is much more complex and is divided into three separate areas, the forebrain, the midbrain, and the hindbrain. The brain is involved in higher functioning such as decision-making, speech, and processing of the senses.
In adult humans, the brain weighs about 3 lbs., with 100 billion neurons, and up to 100 trillion connections.
Investigations using new techniques such as fMRI are expanding knowledge on the relationship between the brain and behavior.
The medulla is located near the top of the spinal column. It is the part of the hindbrain where nerves cross from one side of the body to the opposite side of the brain. It controls life-sustaining functions such as breathing, swallowing, and the beating of the heart. (Ciccarelli & White, 70)[1]
The cerebellum is located at the base of the skull. It is a part of the hindbrain that controls balance and maintains muscle coordination. It controls all involuntary motor movement, such as sitting upright. It also coordinates in voluntary movements that happen in rapid succession, such as walking, dancing, swimming, and even the movements of speech. Learned reflexes and skills are stored here, allowing them to be more automatic. (Ciccarelli & White, 70)[1]
The thalamus is a part of the forebrain that relays information from sensory organs to the cerebral cortex. It is a round structure in the center of the brain. The thalamus performs some processing of sensory information before sending the it to its specific part of the cortex. (Ciccarelli & White, 71)[1]
The hypothalamus is a small structure located below the thalamus and above the pituitary gland. It is responsible for motivational behavior such as sleep, hunger, thirst, and reproduction. It also regulates body temperature, emotions, and hormone regulation.
The hippocampus is named as such due to the fact that it looks like a seahorse. The hippocampus forms long-term memories that are stored elsewhere in the brain.[2]
The amygdala is located near the hippocampus. These two structures are responsible for fear responses and memory of fear.
See also: Atheism and free will
Many liberal scientists believe that modern neuroscience is a subversion of free will, and that the brain is all there is to personality. This is to the direct exclusion of the soul and God's will. For instance, if someone was to commit a crime, that person could be exonerated on the basis of his neurological abnormalities, which are not his fault. Descartes attempted to avoid this issue by placing the soul at the helm of the individual, stating that it was our spirits that truly drive us. The soul attached to the brain via the pineal gland, communicating with the corporeal matter by squeezing the central gland, and pumping cerebrospinal fluid through the body. However, his atheism left no place for communion of the soul with God, and Descartes was also mistaken in the belief that only humans have pineal glands. Many conservative scientists are now taking into account the soul, when they factor in free will, which allows for much more variation among individuals.
See also: Atheism and irrationality
Categories: [Brain] [Anatomy] [Neuroscience] [Nervous Systems]