THE BRAIN THE MIRACLE OF THE BRAIN-YOUTUBE

OVERVIEW--NERVOUS SYSTEM Nervous System Central Nervous System Brain Spinal Cord (connects brain with PNS) Peripheral Nervous System (carries info to and from CNS)

THE BRAIN Hypothalamus Thalamus Pons Reticular Formation Spinal Cord Medulla Brain stem

Spinal Cord “Old” Brain “New” Brain

“OLD” BRAIN 1-Cerebellum: located at the rear of the brain & controls coordination, posture, balance, muscle tone, & control over body movement 2-Reticular Activating System (a.k.a. formation): monitors the general level of activity in the hindbrain & maintains a state of consciousness; Essential for the regulation of waking & sleeping Part of brain stem; alerts cerebral cortex to sensory input 3-Thalamus: relays & translates information from all of the senses, except smell, to higher levels in the brain Relays sensory impulses to cerebral cortex 4-Hypothalamus: plays a major role in the regulation of motivated behavior (hunger, thirst) & controls homeostasis (internal conditions/body temperature) 5-Medulla: the oblong structure at the top of the spinal cord that controls many vital life-support functions such as breathing, waking, heart rate, & blood pressure 6-Pons: located above the medulla; connects spinal cord with lower brain, & lower brain with higher brain regions Helps regulate sensory information & facial expressions

“NEW” BRAIN Cerebrum: regulates higher cognitive & emotional functions Cerebral cortex: outer gray covering of the cerebral hemispheres Cerebral Hemispheres: right & left halves of the cerebrum, covered by the cerebral cortex & connected by the corpus collosum Hemispheric lateralization: specialization of one of the cerebral hemispheres to handle a particular function Left hemisphere: controls right side of body; coordinates complex movements; speech & language in 95% of right handers & in 62% of lefties Right hemisphere: controls left side of body; visual-spatial perception; nonverbal behavior Corpus Callosum: mass of nerve fibers that connect the right & left cerebral hemispheres Split-brain operation: corpus callosum is cut, separating cerebral hemispheres (done in cases of severe epilepsy to reduce frequency of grand mal seizures)

“NEW” BRAIN Left Handedness Right hemisphere more developed Corpus callosum 11% thicker with 25 million more nerve cells 12 times more likely to stutter & have learning disabilities (esp. dyslexia) 2.5 times more likely to have allergies & migraines lefties overrepresented in the following professions: art, music, engineering, math, major-league baseball player

Split-brain operation = corpus collosum is cut, separating cerebral hemispheres (done in cases of severe epilepsy to reduce frequency of grand mal seizures)

Contains four major lobes: Frontal lobe: controls voluntary movement & includes the motor cortex Broca’s area: controls physical production of speech sounds Parietal lobe: contains the primary somatosensory area that manages skin senses Somatosensory cortex Occipital lobe: located in the back of the head & contains the visual cortex Temporal lobe: located on each side of the head above the temples & contains the auditory cortex Wernicke’s area: comprehend spoken word; formulate (cognitively) speech & written language

OTHER PARTS Limbic System = group of structures in the brain that are collectively involved in emotion, memory, & motivational urges Amygdala: emotion, aggression, formation of emotional memory Hippocampus: acquisition of explicit (conscious) memory * #

BRAIN MONITORING PET Scanning (positron emission tomography): creates a visual image of functioning in various parts of the brain by tracing radioactivity emitted by cells MRI (magnetic resonance imaging): provides clear pictures of the structural anatomy & chemistry of the brain by passing a strong magnetic field & radio waves through the person’s head CAT (computerized axial tomography) scan: presents a picture of the human brain by passing X-ray beams through the head at various angles EEG (electroencephalograph): records the electrical activity of the brain How Einstein’s Brain is different than yours-youtube Do men and women have different brains-youtube