The Brain

The brain is a vital part of the central nervous system and serves as the control center for all of the body’s functions including conscious activities such as walking and talking, and unconscious ones such as breathing, heart rate, etc. The brain controls thought, comprehension, speech and emotion. Injury to the brain – whether the result of severe head trauma such as a gunshot wound or a skull fracture, or a closed head injury in which there is no fracture or penetration of the skull – can disrupt some or all of these functions.

Enclosed within the skull, the brain is a gelatinous material that floats within a protective sea of cerebrospinal fluid. This fluid supports the brain and acts as a shock absorber in rapid head movements. Both the brain and the cerebrospinal fluid are protected to some degree within the bony framework of the skull. The outer surface of the skull is smooth, but the inner surface is rough and jagged and can cause significant damage in closed head injuries. In such injuries, the head and body in motion are abruptly stopped, causing the brain to rebound within the skull and move over these rough bony structures.

Areas of the Brain

There are three main areas of the brain:

1. Cortex

The cortex is the largest of the three and is the center where most thinking functions occur. It is divided into four lobes, each of which controls particular functions and skills. Additionally, the cortex is divided into two hemispheres: the right and the left. The left hemisphere is usually the dominant of the two and controls verbal functions such as speaking, writing, reading, and calculating. The right hemisphere usually controls more visual-spatial functions such as visual memory, copying, drawing, and rhythm.

2. Cerebellum

The cerebellum controls coordination, balance and posture.

3. Brain stem (diencephalon)

The brain stem acts as a relay station between incoming sensations and the cortex, which processes and interprets those sensations. The brain stem connects the two hemispheres of the brain to the spinal cord and is also the point of origin for 12 cranial nerves. When incoming stimuli travel through the brain stem and are received by the cortex, a response is generated and then relayed back through the brain stem to the body. Because of its vital role as a relay station and its function in controlling consciousness, alertness and basic bodily functions, the brain stem is perhaps the most critical area in terms of damage to the brain.