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THE CENTRAL NERVOUS SYSTEM Central Nervous System Brain Made up of: • Brain • Spinal Cord Spinal Cord Meninges • Cover the brain and spinal cord 3 Layers • Duramater • Arachnoid mater • Pia mater Gross Anatomy of the Spinal Cord https://www.youtube.com/watch?v=5B87zsAKmWc Gross Anatomy of the Spinal Cord • Anterior median fissure and posterior median sulcus • Divide spinal cord in to right and left halves • Central canal • Contains spinal fluid Gross Anatomy of the Spinal Cord Posterior roots • Axons of sensory neurons Anterior roots • Axons of motor neurons Gangalion • Contain sensory neurons Gray Matter Vs White Matter Gray matter • Divided into Horns • Name based on location White matter • Organized into Tracts • Common origin or destination Spinal Cord Functions White Matter • Sensory impulses travel towards brain • Send out motor impulses Gray Matter • Receives and integrates reflex info Components of a Reflex Arc http://www.youtube.com/watch?v=wLrhYzdbbpE 1. Sensory receptor • Responds by sending nerve impulse 2. Sensory neuron • Sends msg to . . . 3. Integrating center • Processes info Components of a Reflex Arc http://www.youtube.com/watch?v=wLrhYzdbbpE 4. Motor neuron • Pass msg to effector 5. Effector • Responds to stimulus The Reflex Arc Brain Hieroglyphics • Create your own Hieroglyphic B + Rain = Brain Reflex Arc Example • Using the components of the reflex arc, explain why you feel pain Plexuses • Where bunches of nerves meet • Describe regions the nerves supply or course the nerves take • E.x Pinched nerve Which plexus has been damaged? Image for Analysis Question The Patellar Reflex 1. Sensory neuron sends info through the dorsal root ganglion into the spinal cord 2. Signal splits in two • motor neuron to the quadriceps • Interneuron sends message to motor neuron in the hamstring ***The signals work together Did you Know . . . . • The brain uses 20% of the body’s oxygen • Brain damage may occur if brain neurons are deprived of O2 for more than 4 minutes • If blood entering the brain has low glucose levels mental confusion, dizziness convulsions and loss of consciousness may occur Tour De Brain • What are the four major parts of the brain? • Brain stem, diencephalon, cerebrum, and cerebellum • What does the brain stem consist of? • Midbrain, pons, and medulla oblongata Tour De Brain • What is the limbic system made up of? • Amygdala and hippocampus • What does the diencephalon consist of? • Thalamus, pineal gland and hypothalamus Anatomy of the Brain a) Cerebrum b) Thalamus c) Pineal Gland d) Hypothalamus e) Pituitary Gland f) g) h) i) j) k) Pons Spinal Cord Cerebellum Medulla Oblongata Corpus Callosum Midbrain Brain Stem Midbrain • Startle reflex, conducts nerve impulses Pons • Relays sensory info, respiration, chewing, consciousness Medulla Oblongata • Heartbeat, circulation, swalllowing, vomiting, etc. The Brain Stem • https://www.youtube.com/watch?v=snO68aJTOpM Diencephalon Pineal Gland • Produces melatonin, associated with sleep Thalamus • Relay station for sensory impulses Hypothalamus • Maintains homeostasis, body temp and appetite Limbic System (Emotional Brain) Hippocampus • Memory, spatial navigation Amygdala • Fear, aggression, deciphers potential impact of an event Olfactory System • Process smell Anatomy of the Brain Pituitary Gland • Releases hormones Corpus Callosum • Connects two hemispheres of the brain Reticular Formation • Maintains consciousness, arouses from sleep Anatomy of the Brain Cerebellum • Equilibrium, balance, posture Spinal Cord • Integrates spinal reflexes Cerebrum • Divided into four lobes How to Remember the Parts of the Brain • http://www.thepsychfiles.com/200 8/09/episode-72-video-memorizethe-parts-of-the-brain/ The Medulla Oblongata • https://www.youtube.co m/watch?v=cu7A8LIzL1 o • Based on what you learned yesterday, is the clip accurate? Why or why not? What Protects the Brain? 1. Cranium 2. Cranial meninges 3. Blood brain barrier • Allows lipid soluble and anesthetics Cerebrospinal Fluid Flows through brain and spinal cord Carries • O2 • Glucose Removes • Wastes • Toxins Hypothalamus Regulates: 1. Hormones 2. Emotion and Behavior 3. Appetite and Thirst 4. Body Temp 5. Circadian rhythms Cortisol Stress Hormone • Regulates breathing, pulse, blood pressure and arousal Which part of the brain releases it? • Hypothalamus Why do you think the rat acted this way? • When the rat turns a wheel, it receives an electrical stimulus to the medial forebrain bundle, which is rewarding. The rat will continue to do this indefinitely and pass up food, sex, and other “natural” rewards for the artificial stimulus. Hippocampus What happens if it is damaged? • Can not form new long-term memories Amygdala Associated with fear, aggression and pleasure • Positive correlation between size and aggression • Shrinks upon castration What happens when it is removed? • Person becomes tame indifferent and Lobes of the Brain https://www.youtube.com/watch? v=9UukcdU258A The Lobes of the Brain Lobe Frontal Temporal Parietal Occipital Function The Lobes of the Brain Lobe Function Frontal • Motor cortex, voluntary body movements • Reasoning, thinking • Planning, decision making • Language expression Temporal • • • • • Occipital • Vision/visual perception • Object and recognition Parietal • Sense of touch, taste, tactile and temperature • Spatial awareness • Perception (uses the senses) Hearing/Distinguish sounds Visual and verbal memory Understand speech Emotional memory Facial recognition Spatial Awareness https://www.youtube.com/watch?v=sYKI4A3uhc Phineas Gage • http://www.youtube.com /watch?v=kR7_oMSUB FE • https://www.youtube.co m/watch?v=FrULrWRlG BA Phineas Gage 1. Which areas of his brain were damaged during the accident? 2. Why do you think Phineas’ behavior changed after the accident? 3. Based on what you have learned which lobe of the brain controls personality? Lateralization of the Brain Does each hemisphere of the brain have a specific job? Verbal left hemisphere Nonverbal right hemisphere Split Brain Experiments Performed by Dr. Sperry on people with Epilepsy • Excessive nerve signaling Corpus Callosum was severed • Hemispheres can’t communicate Mr. Split Brainy Analysis 1. How would you describe the abilities of the left hemisphere? What leads you to think this? Use data from the experiment to support your answer. 2. How would you describe the abilities of the right hemisphere? What leads you to think this? Use data from the experiment to support your answer. 3. Based on the data you collected during the experiments, which abstract should you send to be published? What leads you to think this? Split Brain Research • The brain isn’t like a computer with specific sections of hardware charged with specific tasks. It’s more like a network of computers connected by very big, busy broadband cables. The connectivity between active brain regions is turning out to be just as important, if not more so, than the operation of the distinct part. Research Findings During the experiment: The right hemisphere is experiencing is own aspect of the world that it can no longer express, except through gestures of the left hand. Morality Question: • Accidentally or intentionally poisoning your boss • Patients reasoned that both scenarios were morally equal • Research suggests that both sides of the brain are necessary for this type of reasoning task W.J. (WWII Paratrooper) • Responded with stimuli sent to left side • No response with stimuli sent to right BUT His left side kept pressing a button when an image appeared • Why? What came out of the Split Brain Experiments? Hemispheres have specialized tasks Right: • Space perception, music, art, facial recognition, emotional context to language. Left • Analytical, verbal processing, speaking/language Provides a good example: http://physics.weber.edu/carroll/ho nors-time/split_brain.htm Continued Some functions lateralized • Certain functions controlled by a specific hemisphere • Never 100% Left Brain vs Right Brain • Do you consider yourself a right brained person or a left brained person? Why? • • Go to the website listed to the right and take the quiz print out your results and paste them in your NB • When you get to the page with the drop down menu answer I don’t want to answer to all questions. • http://testyourself.psycht ests.com/testid/3178 Memory Acquired info is stored and retrieved How is a memory formed? • Structural and functional changes occur Which areas of the brain are involved in memory? • All areas Types of Memory http://thebrain.mcgil.ca/flash/i/i_07/i_07_p/i_07_p_tra/i_07_p_tra.html Sensory Memory • No conscious attention • Perceive stimuli • Lasts about 1 second Short Term Memory • Records limited info • Lasts less than 1 minute • Repetition increases retention Long Term Memory • Permanent storage of short term memory Optical Illusions (AKA Visual Illusions) • They way your perceives and interprets and image