THE HUMAN BRAIN

The Human Brain

The central nervous system is one of the fundamental parts of the human anatomy . It is responsible for the overall function of the human body The most vital part of the nervous system is the brain . The human brain is divided into several parts , but all of these parts are connected to each other . The parts of the brain are the following : the cerebrum cerebellum , brain stem , reticular formation , as well as thalamus and hypothalamus (Toga , 2008

The first part of the brain is the cerebrum . The word cerebrum

' was derived from the Latin word for brain (Toga , 2008 . The cerebrum is very important as majority of the high-level brain functions ' occur in this part of the brain (Toga , 2008 ,

.1 . It is the part of the brain which obtains all information from the senses , and forwards motor commands to the brain and other parts of the body . The cerebrum consists of two hemispheres , both of which account for most of the weight of the human brain . The hemispheres are detached from each other by a fold identified as the longitudinal fissure . Despite being detached , the hemispheres are linked by commissures the biggest commissure is called the corpus callosum (Toga , 2008

The cerebral cortex is the outer surface of the cerebrum it consists of creased layer of cells called gray matter (Toga , 2008 . Underneath the gray matter lies the white matter , a cluster of fibers . The creases of the cerebral cortex consist of gyri , sulci and fissures . It is the gyri and sulci which distinguish the cerebrum into five lobes . These are the frontal , parietal , temporal and occipital lobes , as well as the insula (Toga , 2008 ,

.1

The second part of the brain is the cerebellum (Toga , 2008 . It is responsible for the organization of the actions of the body . It manipulates voluntary actions , as well as sustains both balance and posture through muscle control and limb positioning . The cerebellum is situated in the lower part of the brain below the occipital lobes . Just like the cerebrum , the cerebellum is also divided into two . The cerebellum consists of two lobes linked by white fibers known as vermis The cerebellum is connected to another part of the brain - the brain stem (Toga , 2008

The brain stem is the part of the brain that it considered the most primeval from the evolutionary point of view (Toga , 2008 . The brain stem is in charge of the basic functions of man , like breathing . It consists of three key parts : the midbrain , pons and medulla oblongata The midbrain is located on top of the brain stem . It has relay stations ' to allow neurons to send signals to the cerebral cortex (Toga , 2008 ,

. 2 . It also has reflex centers ' which serve as routes to gather information from the senses as well as motor commands (Toga , 2008 ,

. 2 . The top portion of the midbrain carries both relay and reflex posts for functions of the eyes and ears , while the lower...