2The Nervous SystemIt starts with an individual nerve cell called a NEURON.
3Neuroanatomy Synapse Synapse Neurotransmitters (chemicals held in terminal buttons that travel through synaptic gap)
4How does a Neuron fire?Threshold: level of stimulation needed to trigger a neural impulseAction Potential: electrical charge that travels down the axonAll-or-none response: neuron either fires or it doesn’t, nothing in beteween!Neurotransmitters: chemical messengers that cross synaptic gap b/w neuronsINFLUENCES EVERYTHING WE DO!!! Move, feel…everything!Reuptake: sending neuron reabsorbs some of the neurotransmitter
5Types of NeuronsSensory Neurons (Afferent): carry sensory information to brain & spinal cord (central nervous system)Motor Neurons (Efferent): carry information from brain & spinal cord to muscles & glandsInterneurons: in bran & spinal cord that communicate b/w sensory & motor
7Acetylcholine (ACH) Deals with learning, memory, & muscle movement At every junction b/w motor neurons & musclesWhen released to our muscles the muscle contractsWhen it is blocked muscles are paralyzed & cannot contractAnesthesia?Black widow spider?Is involved in autonomic nervous systemLack of has been linked to Alzheimer’s disease
8DopamineInvolved in movement & posture, alertness, & leveling out moodCocaine (and other drugs) blocks dopamine reuptake=highLack of dopamine has been linked to Parkinson’s diseaseToo much has been linked to schizophrenia (overstimulated brain)
9Serotonin Involved in mood, appetite, arousal Low levels have been linked to clinical depression, suicide, loss of appetite (anorexia)
10GABA (gamma amino-butyric acid) In Central Nervous SystemInduces relaxation & sleepBalances the brainToo little = insomnia, anxiety, epilepsy
11Glutamate Involved in memory & learning Low levels = interferes with memory & learning, sluggish, difficulty concentratingHigh levels = must be “reuptook?” or it can destroy neurons
12Endorphins Natural pain killers Feeling of euphoria, pleasurable emotionsOpiates (morphine, codeine…) bind to receptorsMany of our most addictive drugs deal with endorphinsProduced during exercise“gym rats”
13Drugs can be….. Agonists- make neuron fire Antagonists- stop neural firingReuptake Inhibitors- block reuptake
15Central Nervous System The Brain and spinal cordCNS
16Peripheral Nervous System Peripheral: sensory & motor neurons that connect the Central NS to the rest of the bodyIt’s how the brain & spinal cord communicate w/ sensory receptors, muscles & glandsTravel through nerves (bundled axon cables that connects cns to eveything)Is divided into two categories….somatic and autonomic
17Somatic Nervous System Controls voluntary muscle movementUses motor neuronsLet’s make a list!
18Autonomic Nervous System Controls the automatic functions of the bodyGlands, organs, heartbeat, digestion, etc…Think AUTOMATICDivided into two categories…the sympathetic and the parasympathetic
19Sympathetic Nervous System When you are stressed:Automatically accelerates heart rate, breathing, raises blood sugar, sweat to cool you down…Fight or Flight Response!You body feels “sympathy” for you b/c it thinks you are about to die so it gets you ready to fight or run
20Parasympathetic Nervous System Automatically slows the body down after a stressful eventHeart rate and breathing slow down, lowers blood sugar, etc…Think PARACHUTE
21Reflexes Automatic response to stimuli Normally, sensory neurons take info up through spine to the brainSome reactions occur when sensory neurons reach just the spinal cord (interneurons)Survival adaptation?
22Brain Structures Some scientists divide the brain up into three parts. HindbrainMidbrainForebrainLet’s talk first about the brainstem (hindbrain)
23Medulla Oblongata “Central Office”=keeps your whole body working Located where spinal cord enters the skullControls heart rate, breathing & blood pressure
24Pons Located above medulla Communicates between cerebellum & other parts of brainInvolved in sleep & arousal (awake)Some think involved in dreaming
25SPINAL CORD (the nerves) interneurons that carry signals protected by vertebrae & spinal fluid (cushions the nerves)
26Thalamus Located in Forebrain “Brain’s Sensory Switchboard” 2 egg shaped structuresreceives information from all the senses (except smell) & routes it to the brain regions that deal with vision, hearing, taste & touchit’s the main traffic hub en route to other destinations
27Reticular Formation (reticular activating system) Located between your earsFinger-shaped network of neurons located between spinal cord & thalamusSensory info travels from spinal cord to thalamus & some passes thru RF which filters info & relays it to other areas of the braincontrols arousal (alert)Stimulate that cat! Or put in in a coma
28Cerebellum means “little brain” located in the back of our head Coordinates muscle movements, balance, & emotions
29Limbic System EMOTIONAL CONTROL CENTER of the brain Linked to emotions (fear, anger…), memory & motivation (food, sex…)The 4 “F”sFeedingFightingFearF (sex )Made up of:*Hypothalamus *Hippocampus*Amygdala *Cingulate Gyrus
30Hypothalamus “the brain’s thermostat” perform specific bodily maintenance duties (eating, drinking, body temperature, sex drive…), takes orders from the other parts of the brain“pleasure center”Orchestrates the sympathetic nervous & endocrine systemsinterplay b/w endocrine & nervous systems, both influence each otherEX: thinking about sex can trigger your body to secrete hormones
31Hippocampus and Amygdala Hippocampus is involved in memory processing (creating new memories)Think lost on campus as a freshmen on first dayShaped like a seahorseDamage to this area will prevent you from forming new memoriesAmygdala is vital for our basic emotionsExpressions of Fear & Aggression/Frustration
32Cingulate Gyrus Latin for “belt” emotional responses to pain regulates aggressive behaviorHelps predict negative consequences
33The Brain Made up of neurons and glial cells Glial cells are the “housekeepers” that support & provide nutrition to neural cellsMy husband is my glial cell. He takes care of me (and cleans the house)!!!
34Cerebral Cortex The wrinkled outer layer of our brain Laid out it would be about the size of a large pizza (yum!)YOUR BODY’S ULTIMATE CONTROL & INFO PROCESSING CENTERThinking, perceiving, speakingThis part of our brain separates us from all other animals
35Areas 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 areasDeal with higher mental functions like learning, remembering, thinking & speaking
36Frontal Lobe Deals with higher level thought & reasoning Making plans, forming judgments, performing movementsMotor Cortex: controls voluntary movementsPrefrontal Cortex: problem solving & emotionBroca’s Area: left hemisphere in frontal lobe, controls ability to speak (muscles)Broca’s Aphasia: damage to Broca’s area will impair speaking
37Parietal Lobes Located at the top of our head Receives sensory info about temperature, pressure, texture, & painSomato-sensory cortex: registers and processes touch and movement sensations
38Temporal Lobes Located above the ears Process sound sensed by ears Wernicke’s area: processes the words we hear spokenWernicke’s Aphasia: impairs your ability to understand wordsAngular Gyrus: responsible for understanding written language
39Occipital Lobes Located in the back of our head Handles visual input from eyesRight half of each retina goes to left occipital lobe and vice versa (seriously!!!)
40Corpus Callosum & Basil Ganglia Corpus Callosum: a large band of neural fibers that connect the 2 hemispheres of the brain (we’ll talk about what happens when you cut this this soon)Basil Ganglia: group of neurons that learns, remembers, & coordinates voluntary movement (Williams in Zumba!!!!)
41Hemispheres 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.
42Split-Brain PatientsCorpus Collosum attaches the two hemispheres of cerebral cortex.When removed you have a split-brain patient.
43Brain PlasticityThe ability for our brains to form new connections after the neurons are damaged.The younger you are, the more plastic your brain is.
44Ways to study the Brain!!!Accidents: Phineas Gage.
45Lesions Cutting into the brain and looking for change. Brain tumors also lesion brain tissue.
46Less Invasive ways to study the Brain Electroencephalogram (EEG)Computerized Axial Tomography (CAT)Magnetic Resonance Imaging (MRI)Positron Emission Tomography (PET)Functional MRICHECK OUT LINK ON WEBSITE FOR MORE INFO!
47Endocrine System System of glands that secrete hormones. Controlled by the hypothalamus.Pituitary=“master gland”Ovaries and Testes.Adrenal Gland