Nerves of the Head and Neck

[Continued from above] . . . the white matter and grey matter. However, this chief organ of the nervous system is, as you would expect, extremely complex. The jelly-like substance of the brain is divided into three parts and two sides. The two sides of the brain, called hemispheres, are different in size, shape, and the roles they play. Within those divisions lie others. These hemispheres have areas, called lobes, which perform specific functions. For instance, the motor cortex controls voluntary muscles. The somatosensory cortex receives and analyzes sensory impulses from all parts of the body. Speech and writing are controlled by the area in the frontal lobe of the dominant hemisphere.

Also within the head, major nerve bundles serving the senses (including the eyes, the ears, the smell receptors of the nose, and the taste buds of the tongue) issue out within the head from the brain, sending and receiving electrical signals. The associated limbic system, which lies at the base of the frontal brain, connects to the spinal cord and is the emotional brain, controlling all our instincts of survival. Below the cranium, lying half within the skull and half within the neck, the brain stem extends with the roots of all the major nerves that serve the body. Inside the protective enclosure of the spinal column's cervical vertebrae, the brain stem evolves into the nerves of the spinal cord, where certain nerves exit the spine regularly from between foramina of those vertebrae. Damage to any part of the spinal cord may cause a loss of sensation and/or motor function below the injury; however, such injuries are most dangerous within the neck as they are likely to affect a greater area of the body and are more likely to result in death.

Together, the brain and spinal cord make up the central nervous system, and through these uppermost components of the central nervous system of the head and neck, we are able to think, reason, love, forgive, create and remember, as well as to survive through automatic processes such as breathing and digesting.