Cerebral Cortex

1. Cerebral Cortex CerebralCortex Cerebral Cortex - The outermost layer of the brain containing gray matter. Responsible for many "higher-order" functions like language and information processing.

2. Layers of the Cerebrum • Gray Matter • Outer layer of the brain • Composed of neuron cell bodies (site of nucleus) • Includes regions of the brain involved in muscle control, sensory perceptions, like seeing and hearing, memory, emotions, speech and critical thinking/problem solving Cell Body of Neuron

3. White Matter Contains mainly long, myelinated axons Involved in the relay of sensory information from the rest of the body to the cerebral cortex Layers of the Cerebrum Myelin = fatty outer covering of axons. Allows for faster transmission of message. Axon of Neuron

4. Limbic System • set of evolutionary primitive brain structures • involved in emotions and motivations, like the ones related to survival • fear, anger, sexual behavior • also involved in feeling of pleasure • eating and sex

5. Limbic System Structures • Amygdala – linked to both fear responses and pleasure. Anxiety, autism, depression, post-traumatic stress disorder, and phobias are linked to abnormal functioning • Hippocampus – sends memories out to the appropriate part of the brain for long-term storage and retrieves them when needed. • damage to hippocampus can cause an inability to form new memories Amygdala shrinks by more than 30% in males upon castration – minimizes pleasure

6. Diencephalon – “Interbrain” • Sits on top of the brain stem • Enclosed by the cerebral hemispheres; well-hidden brain region • Made of three parts • Thalamus • Hypothalamus • Epithalamus

7. Thalamus • The relay station for sensory impulses (switchboard) • Transfers impulses to the correct part of the cerebrum for interpretation • All incoming impulses get sorted here first and identified as pleasant or non-pleasant

8. Under the thalamus Controls organs by maintaining homeostasis Important autonomic nervous system center Helps regulate body temperature Controls water balance Regulates metabolism Hypothalamus • The pituitary gland is attached to the hypothalamus. It releases hormones which affect growth, sexual development, metabolism and reproduction.

9. Helps to regulate the sleep/wake cycle by releasing hormones like melatonin from pineal gland Controls some parts of emotions and mood Epithalamus Epithalamus

10. Brain Stem • Attaches to the spinal cord; primitive “rat brain” • Controls automatic behaviors necessary for survival (breathing) • Parts of the brain stem each about an inch long • Midbrain • Pons • Medulla oblongata

11. Brainstem • Midbrain = Smallest region of the brain which relays auditory and visual information. • Alsocontrolseye movements, like blinking • Pons = “bridge” of the brainstem. Controls Breathing. • Medulla Oblongata = The lowest part of the brain stem • Merges into the spinal cord • Contains important control centers • Heart rate control • Blood pressure regulation • Breathing • Swallowing • Vomiting

12. Cerebellum • contains ~70% of all the brain's neurons; yet is only 10% of the volume of the brain! • contributes to precise timing of skeletal muscle activity (i.e. walking, running or standing on your hands) • controls our balance and equilibrium • Doesn’t function well under influence of alcohol • Works like ‘auto pilot’ – monitors body position and amount of tension in body parts

13. Cerebellum and other brain parts Meninges = three connective tissue membranes covering and protecting brain Dura Mater: outermost meninges; tough and thick. Can restrict movement of the brain within the skull. Protects the brain from movements that may stretch and break brain blood vessels.

14. Central Nervous System Disorders • Meningitis = inflammation of meninges. Serious threat since bacteria or viruses can spread to brain. • Concussion = injury is slight; dizzy, see stars, or lose consciousness briefly but no permanent damage. • Stroke = blood circulation to a brain area is blocked from ruptured blood vessel or blood clot.

15. More Brain Disorders • Hemorrhage = bleeding from ruptured blood vessels. • Aneurysm= dilation, bulging or ballooning out of part of the wall of a vein or artery in the brain • Can get larger over a lifetime • Pushes on brain regions causing symptoms like blurred vision, stutter, etc. • Can hemorrhage

16. What brain structures can you see?