CLASS TWO Handout #5 The Brain Structure

The brain is made up of about 100 billion nerve cells call neurons and trillions of “support cells” called “glia”.

These nerve cells communicate using chemicals called neurotransmitters.

NEUROTRANSMITTERS THAT INFLUENCE BEHAVIOR

 Serotonin – helps regulate mood, assists in transmission of neural messages

 Adrenaline: Epinephrine – gets the body moving instantly

Norepinephrine gets the brain’s attention

 Dopamine – controls physical movement  Endorphin – the body’s morphine  Cortisol – produced by long term stress

1. Cerebral Cortex – This is a sheet of tissue that makes up the outer layer of the brain. The word “cortex” comes from the Latin word for “bark” (of a tree). The thickness of the cerebral cortex varies from two to six millimeters. The right and left sides of the cerebral cortex are connected by a thick band of nerve fibers called the corpus callosum. The cerebral cortex controls functions that include thought, voluntary movement, language, reasoning, and perception. Malfunction of this area in the brain could cause symptoms that include poor judgment, impulsivity, delusions, hallucinations, and language disorders. 2. Cerebellum – The word “cerebellum” comes from the Latin word for “little brain.” This region of the brain controls cognitive functioning, movement, balance, and posture. 3. Thalamus – The thalamus receives sensory information and relays the information to the cerebral cortex. This area also transmits information from the cerebral cortex to other areas of the brain and spinal cord. The thalamus is involved with the functions of sensory and motor integration.

4. Hypothalamus – The hypothalamus controls behavioral responses such as feeding, drinking, sexual response, aggression, and pleasure. This area is involved in almost all aspects of behavior including our biological clock that is linked to the daily cycle.

5. The Limbic System – This is a group of structures that includes the amygdala and the hippocampus and is located within the brain. This area of the brain is important for controlling the emotional response. It is also responsible for memory.

6. Hippocampus – The hippocampus is one part of the limbic system that is important for memory and learning.