So far on this journey through the exciting field of neuroscience, we have explored the plasticity of the teenage brain, the anatomy of a neuron and its action potential, neurotransmitters, and glutamate and its implications on studying. Today, we will deviate from our local roads and merge onto the highway: we are finally ready to discuss the overarching central nervous system (CNS), which could be considered the storehouse of these regional neurological concepts. We will investigate the central nervous system and the lobes of the brain.
So what neurological structures are included in the CNS? The central nervous system is the brain and the spinal cord (1). It is called the “central” nervous system because these two organs communicate with sensory receptors, muscles, and glands. The CNS and the peripheral nervous system uses a system of afferent, efferent, and interneurons to transmit neural signals to each other.
The most important organ in the CNS, and arguably, in the entire human body, is the brain. This 3 lb piece of muscle is responsible for our reality, beliefs, dislikes, desires, and actions. The brain consumes 20% of the human body’s oxygen intake and contains about 86 billion neurons listening and talking to each other (2). The brain features grey matter, which is the brain tissue comprised of neuronal bodies and white matter, which is the glial cells that allow for the quick dispatch of neural messages. Another interesting component of the brain are the neural networks, which are a cluster of neurons located in the brain that are strengthened by feedback and lead to a kill. Currently, in my brain, there is a neural network that controls my writing skills.
The brain is comprised of four lobes that have association areas. Association areas are certain areas of the brain that one lobe has dominance in but doesn’t do it alone. While it is not a lobe, the cerebrum, which contains the cerebral cortex, is considered to be the “crown jewel” of cognition. The cortex is where muscle control, spatial skills, and sensory decoding takes place. The four lobes of the brain are the frontal, parietal, temporal, and occipital lobes. The frontal lobe, located in the front of the brain, hence the name, is responsible, to an extent, for executive functions, working memory, personality, behavior inhibition, and regulation of emotions.
Within the frontal lobe is the precentral gyrus, which the brain’s motor center. The parietal lobe near the middle of the brain is the lobe responsible for temperature, touch, pressure, pain, and the sense of having parts of the body in relation to other parts of the body. Within the parietal lobe is the postcentral gyrus, also named the somatosensory cortex, which is associated with sensing heat, cold, and pressure. Underneath the parietal lobe is the temporal lobe, which is associated with hearing. The occipital lobe, at the back of the brain, is the brain’s vision center.
The brain is studded with fissures and sulci that separate various lobes and cortices. The parietocciptical fissure separates the occipital lobe from the two parietal lobes. The central sulcus separates the frontal and parietal lobes. The lateral fissure separates the temporal lobe from the frontal and parietal lobes. The longitudinal fissure is a deep groove that separates the brain into the right and left hemispheres.
Lastly, the spinal cord is the communication highway between the central nervous system and the peripheral nervous system.
In my next article, we will explore the midbrain and limbic systems to complete our tour of the central nervous system.
References and Footnotes
(4) Featured Image Credit: https://www.anatomynote.com/human-anatomy/nerves-system/central-nervous-system/