Bridge between the lower higher levelslayers involved in sleepingwakefulness

Bridge between the lower higher levelslayers involved

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: “Bridge” between the lower & higher levels/layers; involved in sleeping/wakefulness & respiration (damage is often fatal)2.Cerebellum: “little brain” attached to brain stem; balance, coordination, fine motor movements, walking & certain types of learning & memorya.Does NOT initiate movement, but helps to coordinate the timing of the muscles involved (ballet dancers, cats have well-developed)b.Alcohol intoxication affects cerebellum àinability to walk a straight line, touch your nose, etc…c.Damage:jerky, uncoordinated movements; lurchingThe Midbrain (2)Connects hindbrain & forebrain Contains sensory & motor pathwaysRelay center for visual & auditory infooCollects nerve impulses from visual & auditory systems & passes them on to forebrain (thalamus) Involved in eye movementsoMotion in peripheral vision àmidbrain directs gaze toward itocoordinates body movements & eye movement1.Reticular formation: extends from hindbrain all the way up through the forebraina.Involved in sleep/wake cycles & acts like a gate-keeper to help attention
i.Sends messages up to the forebrain that there is some input (ascending portion), then receives orders to ‘let it through’ or to ‘block it’ (descending portion)ii.Also allows us to consciously register other signals (i.e. pain)The Forebrain (3)A.k.a cerebrum; consists of two halves (cerebral hemispheres); includes cerebral cortexComplexity of the forebrain distinguishes humans from other animalsWith mostforebrain structures, there are really two of them, one on each side1.Thalamus: relay station for sensory input (switchboard)a.Specific areas of thalamus deal with a specific sense; send signals on to specific sensory areasb.Abnormal thalamus: garbled sensory info (schizophrenia)2.Basal ganglia: group of structures involved in initiatingvoluntary movements (B.G. >cerebellum)3.Hypothalamus: connects to the pituitary gland (master gland), controlling many hormones (regulate stress, metabolism, & sexual development/activity)a.Basic biological urgesb.Electrical stimulation of this area >pleasure4.Limbic system:a.Nucleus accumbens:reward & motivation; connections from hypothalamusi.Sex, drugs, favorite foods activate this area >release of dopamine (predictive cues can cause dopamine release)b.Amygdala: emotional response (aggression, fear)i.Can produce emotions without higher brain areas “knowing”ii.May basis for “unconscious” fears or other emotional responsesc.Hippocampus: forming & retrieving memories; critical to processing spatial infoi.Damage: can’t form long-term memoriesThe Cerebral CortexCerebral cortex: thin, wrinkly layer on the very outside of the brainwhat reallysets us apart from animals, we don’t have largest brain, but a LOT more cortexour cortex contains about 80% of the neurons in our entire brainAnatomyAll people’s brains have basically the same foldsLongitudinal fissure: divides brain into right & left hemispheresCentral sulcus: divides brain into front & rear portionsLateral fissure: divides upper portion from lower portionFunction

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