The Brain

Made up of neurons 23 billion nerve cells and 300 trillion synapses Glial cells – support, nourish (soma) and protect interneurons (provide insulating myelin) My husband is my glial cell. He takes care of me!!! Whose yours?

Ways we Study the Brain Accidents Lesions CAT Scan PET Scan MRI Functional MRI

Accidents Phineas Gage Story Personality changed after the accident. What this this tell us? That different part of the brain control different aspects of who we are.

Lesions Removal or destruction of some part of the brain. Frontal Lobotomy

Electroencephalogram EEG Detects brain waves through their electrical output. Used mainly in sleep research.

Computerized Axial Tomography CAT Scan 3D X-Ray of the brain. Quick views of brain injury, tissue damage due to trauma Shows tumors

Magnetic Resonance Imaging MRI Uses magnetic fields and radio waves to produce images of brain structures Does not provide info about how actively the brain in functioning

Positron Emission Tomography PET Scan Measures the concentration of glucose in active areas of the brain Limited to monitoring short tasks Still pictures

Functional MRI Identifies most active areas of the brain during a specific mental task Measures oxygen levels and blood flow to the brain Structures and functions of the brain

Brain Structures Scientists divide the brain up into three parts. Brain Stem Limbic System Cerebral Cortex

Brain Regions Brainstem – medulla, pons, reticular formation, thalamus, cerebellum Limbic System – Hippocampus, Amygdala, Hypothalamus Cerebral Cortex – frontal lobe, parietal lobe, temporal lobe, occipital lobe,

Brain Stem Part of the brain with the oldest ancestry 5 Regions: – Medulla – Pons – Reticular formation – Thalamus – Cerebellum Controls involuntary muscles Routes nerves from left side of brain to the right side

Medulla Oblongata Brain’s Autopilot - works with nervous systems…. Autonomic nervous system Controls:

Pons Acts as a bridge between the brain stem and cerebellum Involved in forming facial expressions. Coordinates functions between left and right side of brain

Cerebellum “little brain” attached near brain stem Coordinates muscle movements - Like tracking a target. Controls balance Relies on visual information to coordinate voluntary movement

Reticular Formation Responsible for arousal and ability to focus attention. If stimulated If destroyed

Thalamus Receives sensory information and routes it to appropriate areas of the brain. - all sensory information accept smell. Like a switchboard.

Limbic System EMOTIONAL CONTROL CENTER of the brain. Located between the brainstem and cerebral hemispheres Made up of Hypothalamus, Amygdala and Hippocampus.

Hypothalamus Controls the 4 F’s. Fight (endocrine system) Flight Food (hunger & thirst) Fornication (sex drive) Endocrine System – Pituitary Gland Maintains homeostasis Brain’s Reward system – what neurotransmitter?

Hippocampus Hippocampus is involved in memory formation, processing, and storage.

Amygdala Amygdala is vital for our basic emotions. Fear and Aggression

Cerebral Cortex Cerebral cortex - thin layer of interconnected neural cells Glial cells Fissures – folds that increase the surface area of the brain. – Laid out it would be about the size of a large pizza.

Areas of the Cerebral Cortex Divided into eight lobes, four in each hemisphere (frontal, parietal, occipital and temporal). Any area not dealing with our senses or muscle movements are called association areas.

Parietal Lobes Located at the top of our head. Receives sensory input for touch

Sensory Cortex Registers and processes body touch and movement sensations More sensitive the body region, the larger the area devoted to it

Frontal Lobe Planning, emotional control abstract thought, logic, Moral Reasoning personality development.

Motor Cortex Controls Muscle Movement Body areas requiring precise control occupy the greatest space

Temporal Lobes Process sound sensed by ears. Receive info from the opposite ear.

Occipital Lobes In the back of our head. Handles visual input from eyes. Right half of each retina goes to left occipital lobe and vice versa.

Language Development Aphasia – impairment of language Frontal Lobe – Broca’s Area – directs muscle movements involved in speech Temporal Lobe – Wernicke’s Area – language comprehension and express

Hemispheres Divided into a left and right hemisphere. Contralateral controlled- left controls right side of body and vice versa. Brain Lateralization. Lefties are better at spatial and creative tasks. Righties are better at logic.

Split-Brain Patients Corpus Collosum attaches the two hemispheres of cerebral cortex. Removed in patients with severe epilepsi When removed you have a split-brain patient.

Brain Plasticity The ability for our brains to form new connections after the neurons are damaged. The younger you are, the more plastic your brain is.