NERVOUS SYSTEM

The nervous system includes the spinal cord and the brain.   

The spinal cord is a thick bundle of nerves.  The brain sends and receives electrical impulses up and down the spinal cord. 

The vertebrae are bony structures that create the spine.  They form a protective shield for the spinal cord.  

If serious injuries occur to the spinal cord, no movement or felling occurs below the injury.  If an injury were to happen at the top of the spinal cord where it attached to the head, death usually occurs. 

The brain consists of 4 basic parts: the cerebellum, cerebrum, brain stem, and hypothalamus.

The cerebrum is the largest section of the brain.  It is divided into two halves, which control language, conscious thought, vision, and personality. 

The left side mainly controls language and speech.  The right side controls math and music.

The cerebellum controls balance, posture, and coordination.  

At the top of the spinal cord is the brain stem.  The brain stem control involuntary actions such as breathing, swallowing, heart contractions, digestion, and movement of blood through various vessels. 

The medulla is an enlarged area of the brain stem.  It controls the function of internal organs.

The hypothalamus controls blood pressure, heart rate, temperature, hunger, thirst, and emotions.

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