Brain Disorders Scientific Facts Overview

Because the brain controls almost all of the functions of the human body, injury to the brain can affect many different parts of the body. Brain disorders, which may be inherited or caused by infections, and head injuries can affect the way the brain works and upset the daily activities of the rest of the body.

The nervous system is the body's communication center. The central nervous system (CNS) includes the brain and the spinal cord while the peripheral nervous system (PNS) is composed of nerves. Together, the CNS and PNS control every function of the body, from breathing and blinking to memorizing facts for a test. Nerves from the spinal cord branch outward to the rest of the body. Sensory nerves gather information from the environment and send that information to the spinal cord, which then speeds the message to the brain. The brain makes sense of that message and fires off a response. Motor neurons deliver instructions from the brain to the rest of the body.

The brain is composed of three main parts: the forebrain, midbrain, and hindbrain. The forebrain consists of the cerebrum, thalamus, and hypothalamus (part of the limbic system). The midbrain consists of the tectum and tegmentum. The hindbrain is composed of the cerebellum, pons, and medulla.
The cerebrum or cerebral cortex is the largest part of the human brain. The cerebrum is associated with higher brain function, such as thought and memory. The cerebral cortex is divided into four sections, including the frontal lobe, parietal lobe, occipital lobe, and temporal lobe.

The frontal lobe is associated with reasoning, planning, parts of speech, movement, emotions, and problem solving. The parietal lobe is associated with movement, orientation, recognition, and perception of stimuli. The occipital lobe is associated with visual processing. The temporal lobe is associated with perception, memory, speech, and recognition of auditory stimuli.

A deep furrow divides the cerebrum into two halves, the left and right hemispheres. The corpus callosum is a bundle of axons that connects these two hemispheres. The two hemispheres look symmetrical but are proven to function slightly differently. The right hemisphere is associated with creativity while the left hemisphere is associated with logic abilities.

Nerve cells make up the gray surface of the cerebrum. White nerve fibers underneath carry signals between the nerve cells and other parts of the brain and body.
The neocortex occupies the bulk of the cerebrum. This is a six-layered structure of the cerebral cortex that is only found in mammals. It is believed that the neocortex is a recently evolved structure and that it is associated with "higher" information processing among more evolved animals (such as humans and other primates).

The cerebellum, or "little brain," is similar to the cerebrum in that it has two hemispheres and a highly folded surface or cortex. This structure is associated with regulation and coordination of movement, posture, and balance.

The limbic system, often referred to as the "emotional brain," is found buried within the cerebrum. The lymbic system contains the thalamus, hypothalamus, amygdala, and hippocampus.

Underneath the limbic system is the brain stem. The brain stem is composed of the midbrain, pons, and medulla. This structure is responsible for basic vital functions such as breathing, heartbeat, and maintenance of blood pressure. Scientists describe the brain stem as the "simplest" part of the human brain. In some animals that appeared early on the evolutionary scale (such as reptiles), the entire brain resembles a human brain stem.
Disorders of the brain can occur as the result of infection, such as meningitis and encephalitis, or traumatic head injury, such as a concussion or contusion.
 

Related Terms
Amygdala, bacterial meningitis, brain inflammation, brain injury, cerebellum, cerebral cortex, cerebral edema, cerebrum, chickenpox, closed head injury, computerized tomography, concussions, contusions, corpus callosum, CT, EBV, encephalitis, Epstein-Barr virus, ethylmalonic encephalopathy, forebrain, herpes simplex, hindbrain, hippocampus, hypothalamus, ICP, ICP monitor, intracranial pressure, laceration, limbic system, Lyme disease, magnetic resonance imaging, measles, medulla, meningitis, midbrain, MRI, mumps, neocortex, photophobia, pons, Rocky mountain spotted fever, rubella, TBI, thalamus, traumatic brain injury, varicella zoster, viral encephalitis, West Nile virus.

Natural Standard Monograph (www.naturalstandard.com).
Copyright © 2008 Natural Standard Inc. Commercial distribution or reproduction prohibited.
The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.
Natural Standard Monograph, Copyright © 2008 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.