The Brain Chapter 3: Module 08

Brainstem Oldest part of the brain Responsible for automatic survival functions Location: where spinal cord swells and the brain begins Rose or tail

Medulla The base of the brainstem Controls life-supporting functions like heartbeat and breathing Damage to this area can lead to death.

Reticular Formation A nerve network extending up and down the spinal cord into the brain. Controls an organism’s level of alertness. Damage to this area can cause a coma.

Thalamus Sits atop the brainstem The brain’s sensory switchboard -- directs messages to the sensory receiving areas in the cortex. All senses except smell! Thalamus is Greek for “inner chamber.”

Cerebellum Latin for the “little brain” Located in the rear of the brain Controls balance, muscle coordination and memories on how to use your body. Walking Playing guitar If damaged, the person could perform basic movements but would lose fine coordination skills.

Limbic System A ring of structures around the thalamus; at the border of the brainstem and cerebral cortex Helps regulate memory, aggression, fear, hunger, and thirst Includes 3 parts: the hypothalamus, hippocampus, and amygdala

Hypothalamus Located under the front of the thalamus Regulates eating, drinking, body temperature, and the fight or flight reaction to stress Plays a role in emotions and pleasure

Hippocampus Wraps around the back of the thalamus Plays a role in processing new memories for permanent storage Looks something like a seahorse Hippo is Greek for “horse.”

Amygdala (ah-MIG-dah-la) Two almond shaped structures Controls emotional responses such as fear and anger

Cerebral Cortex The body’s ultimate control and information processing center Covers the brain’s lower level structures Contains an estimated 30 billion nerve cells Divided into four lobes

Longitudinal Fissure The crevice that divides the brain into two halves or hemispheres This and other fissures in the brain create major divisions in the brain called lobes

Corpus Callosum The large band of neural fibers that connects the two brain hemispheres and carries messages between them Is sometimes cut to prevent seizures

Frontal Lobes The portion of the cerebral cortex lying just behind the forehead Is involved in making plans and judgments Includes the “Motor Strip” Band that controls bodily movements

Parietal Lobes Regions available for general processing, including mathematical reasoning Designated as the association lobes Behind the frontal lobes Includes the “Sensory Strip” Band that registers and provides sensations

Occipital Lobe Interprets visual information Located in the back of the head

Temporal Lobes Major center for hearing and some speech functions. Located roughly above the ears

Hemispheric Differences “Left-brained” and “right-brained” debunked Brain is divided into two hemispheres but works as a single entity. Both sides continually communicate via the corpus callosum.

The Brain’s Left Hemisphere For most people, language functions are in the left hemisphere. For a small percentage of people, language functions are in the right hemisphere. Nobody is quite sure why this is… 2 important parts of left brain: Broca’s area Wernicke’s area

Broca’s Area Located in the left frontal lobe Responsible for expressive language Directs muscle movement used in speech If damaged the person can form the ideas but cannot express them as speech Ex. A stroke

Wernicke’s Area Located in the left temporal lobe Involved in controlling receptive language; our ability to understand what someone else says

The Brain’s Right Hemisphere Houses the brain’s spatial abilities To perceive or organize things in a given space, judge distance, understand geometric objects, etc. Helps in making connections between words

Plasticity The ability of the brain tissue to take on new functions Greatest in childhood Important if parts of the brain are damaged or destroyed