PSY 100 1st Edition Lecture 9 Outline of Last Lecture X. Review of the BrainA. New vocabularyOutline of Current LectureXI. The Nervous System: Guest LectureA. CNS versus PNSB. More on the brainCurrent LectureXI. The Nervous System: Guest LectureAnatomy of a neuron: dendrite, soma (body), axon and terminal. The flow of information is electrical and always goes dendrite to terminal never visa versa.Synapse: presynaptic nerve (first) and postsynaptic nerve- neurotransmitters transmit different chemicals such as dopamine, serotonin etc.The electrical signal moves down axon towards synapse.At the synapse neurons communicate chemically (electrically inside nerves and chemically between nerves).Think of the nerve as a tube, there are different concentrations of ions on the outside and inside of the tube. Ions move across the tubes membrane causing electricity.Action potential: part of the neural tube opens to allow positive ions in the cell and negative ions out.The amplitude of the action potential cannot be changed but the frequency can.Threshold: point reached where enough ions are moving across the membrane that the electricity cannot be stopped. Analogy- firing a gun, once the bullet is released it cannot be retracted.Serotonin can float away, be broken down by enzymes or presynaptic nerves can take it back up and re-use it.Alcohol:These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.1. Lowers the starting point of the action potential2. Makes it difficult to reach threshold3. Decreases rate at which nerves fireA. CNS versus PNSThe nervous system can be divided into two parts: 1. Central nervous system-Brain: center of the nervous system, controls all functions-Spinal cord: connects brain to PNS, simple reflexes that do not reach consciousness-Retina2. Peripheral nervous system-Motor and sensory nerves-Cranial nerves: bilateral, 12 pairs of cranial nerves, responsible for sensory, motor and special senses.The peripheral nervous system can be divided into two parts:1. Somatic: controls body’s skeletal muscles2. Autonomic: controls the glands and muscles of internal organs.Autonomic can be divided into two parts:1. Parasympathetic: “rest and digest”2. Sympathetic: fight or flight, moves blood to muscles, hormones released etc.Spinal cord tracts are bundles of nerves that run up the spinal cord.New VocabularyProprioception: sense of self in spaceNociception: painThermoreception: heatFine touch: ability to feel detail, can distinguish two different point of touchCrude touch: unable to distinguish detail, cannot feel two separate pointsB. More on the brainThe brain makes up about 2% of our body weight and uses approximately 20% of our blood supply.Cerebral spinal fluid: there to help protect and cushion the brain, goes down the spinal cord and also behind the retina.Motor cortex: arch shaped region at the back of the frontal lobe, directs muscular outputSensory cortex: posterior to motor cortexPlasticity: brains ability to change by building new pathways or reorganizing based on experience. Parts of the brain that are not used will “shut off”.Agnosia: disorder of recognition, not issue of eyes but of the brainProsopagnosia: face blindness, cannot recognize faces. All visual systems in tact, damageto the inferior aspect of the temporal lobeHemispatial neglect syndrome: brain damage causes person to only see half of their visual fieldThe dominant eye (side of the brain) sees both visual fields while the non-dominant seesonly one side of the visual field. This makes it possible for a person to damage one side of their brain (if the non-dominant) and still see the entire visual