Anatomy of the Brain 1 Nervous System o Central CNS brain and spinal cord o Peripheral PNS nerves connect CNS to muscles organs skin Somatic Somatosensory skeletal motor Cranial and spinal nerves Autonomic Glands and organs Sympathetic Parasympathetic o Two kinds of nerves CNS to body Afferent Sensory go toward CN from receptors May may not be myelinated Motor go out from CNS to Efferent muscles organs Always myelinated Skull and Meninges o Protect brain Packing o Meninges contain blood vessels Dura Mater Arachnoid Pia Mater in PNS too o Pathologies of Meninges Meningitis Inflammation cause by bacteria virus swell in subarachnoid space INCR intracranial pressure Brain Injuries Blood collect b t meningeal layers Epidural Subdural hematoma Subarachnoid hemorrhage INCR intracranial pressure Sulci and Gyri o Sulci sulcus grooves o Gyri gyrus bumps ridges o Form between brain regions o WHY During develop tension pulls regions w many connections into gyri Explain why gyri have specific functions Sulci form where there are fewer connect Deeper fissure o Central sulcus b t frontal parietal lobes o Lateral fissure b t ant frontal temporal lobe post temp parietal lobe o Parietooccipital fissure sup b t parietal occipital and inferior b t temporal occipital o Intrahemispheric fissure b t RT LT lobes Frontal Lobe o Phineas Gage 3ft metal rod through frontal lobes Personality changed to rude profane Unable follow through with plans Loss of prefrontal cortex o Frontal lobe is one of last things to activate PET scan at 5 cool at 30 hot o More moral social control more active frontal lobe more developed prefrontal cortex o Frontal lobe not fully on until late teens early twenties Show schizophrenia at this time Cannot separate two rules First sort shape then Sort color unable to do o Prefrontal cortex Functions Planning Decision making Introspection correlated w size Organize thoughts action carry out goals Social control Morality Personality Superior Frontal Gyrus Locate LT sup frontal lobe contains part of prefrontal cortex top gyrus Activated during introspection Important planning movement Middle Frontal Gyrus Part of prefrontal cortex Complex behavior attention and lying Inferior Frontal Gyrus Part of prefrontal cortex More developed better control over Imp for controlling impulsivity impulsivity low risk behavior Broca s Area Part of inf frontal gyrus next to temporal lobe language center Imp for speech production Named for Dr Paul Broca who studied it Broca s Aphasia speech Loss of ability understand or express Cause when area is damaged neurons die high stroke susceptibility Speech labored disjointed non fluent Word comprehend okay grammar lost depends of depth if deep lose ability to understand others themselves o Primary Motor Cortex Located at pre central gyrus frontal lobe Moves muscles in the body Amt of cortex devoted to a function is related to complexity of function o Pre Motor Cortex Anterior to primary motor Mirror Neurons visualization neurons Discovered in macaque monkey Activates when does an action or when another does same action Observed in neurons of humans as well using epilepsy patients Implications understand intentions learning and empathy Mannerisms personality etc stem from mirror neurons and genetics o Primary Sensory Cortex Located at post central gyrus parietal Receive all sensory input Inputs to cortex are organized systemically Segregated into dermatomes on spinal cord Sensory Homunculus Areas w finer sensory discrimination have more cortex Dermatome spread out over large areas are smaller on the homunculus Cortical Processing has limits Just listen while driving statistically impaired Auditory process supersede thinking capabilities while driving Occipital Lobe o Posterior inferior cerebral hemisphere o Visual functions o Primary Visual Cortex Receives input from eyes via limbic areas Damage to this area causes blindsight No perception of sight but can navigate mazes and perform other visual tasks Temporal Lobe o Important for hearing memories obj recognition language and emotion o Wraps around to ventral medial surfaces of brain Fusiform gyrus complex obj recognition Recognition of face Prosopagnosia Inability recog faces cause by brain damage inherited 2 5 pop Lost ability to put context to things recognize Parahippocampal gyrus memory form o Superior Temporal Gyrus Inf border of temporal fissure Primary Auditory Cortex Tonotopic map Damage to this area removes awareness of sound Patients still respond reflexively to startling noises o Wernicke s Area Language comprehension area lang abilities usually focused on left side of brain Damage to area causes Wernicke s Aphasia Patients language has normal rhythm doesn t make sense Different from Broca s aphasia Massive connect b t Broca s and Wernicke s Often children read aloud when learning Damage to one likely cause damage to other o Middle Temporal Gyrus Important for sensory integration plus language and semantic memory Associated w auditory verbal hallucinations in schizophrenia Bring together occipital and temporal auditory o Inferior Temporal Gyrus Important for complex visual processing Nothing to do with auditory only visual processing Cortical thickness changes as function of IQ level Born with more neuron there process more info as become smarter area become more involved Parietal Lobe o Posterior superior part cerebrum o Integrates sensory systems into a single world view that is unique to each person Sensation of temp touch pressure pain from skin o Most recent evolved takes in primary auditory visual sensory input and gives a world view o Integration center seems seamless to you Where in brain do distinct areas arise Look homogenous but many diff areas Phrenology o Develop in 1796 by Franz Joseph Gall o Pseudoscience base on skull measurement o Each faculty of mind must have its own organ in brain o Based on ripples in bone Brodmann Areas o Developed by Korbinian Brodmann in 1909 o Based on distinct organize of neurons in each area Cell staining microscopy o Functionally distinct each gyri do something diff b c look diff under microscope Each wired to do something vastly different o Still in use today How determine functions of different brains areas Patients with brain injuries or abnormalities Normal humans o Functional neuro image EEGs fMRI and PET helpful in look at what areas active in use can be highly misleading Studies with animal models o Lesion studies o Electrophysiology Why do we