September 2 2014 o Thinking perceiving big part of emotion and memory drive related behaviors o Cortex folded stuff structures deep to cortex thalamus and hypothalamus hippocampus The more folds in the brain the more intellectual the being The folds in the brain are used to maximize surface area Gross Anatomy of the Brain 4 1 4 2 Humans vs Other Mammals Same o Brain areas o Chemicals neurotransmitters0 o Proteins channels and receptors Different o Overall brain size o Size of individual parts Neocortex primates Olfactory bulbs rodents Auditory cortex bats Muscles and sense organs of forelimbs monkeys 3 Primary Divisions of the Brain Forebrain and amygdala basal ganglia o Humans have a very large forebrain very highly developed o Sensory pathways visual and auditory processing reflexes o Top portion of brainstem o Some motor control reflexes breathing heart rate etc o Bottom of brainstem pons medulla and cerebellum Midbrain Hindbrain Brainstem Medulla pons and midbrain in order from bottom to top o Medulla meDULLa Controls vital reflexes Damage to medulla can be fatal Trauma drugs etc can cause damage Controls heart rate and breathing o Pons bubble in the brainstem o Midbrain Intrinsic descending pain control Reflexive orienting to visual and auditory stimuli Ability to not feel pain And more Substantia nigra Parkinson s Disease Cranial Nerves 12 pairs Most enter exit the ventral surface of the brainstem Sensory and motor for head and face Important in neurological exams Some have autonomic component pupil constriction tearing salivating cardiovascular functions Cerebellum Movement o Rate range force direction o Well learned movements o Sensory timing o Balance and postural control Forebrain Cortex Thalamus Hypothalamus o Relay station filter for sensory info on its way to the cortex o Involved in man other systems motor emotional memory etc o Communicates with pituitary gland to alter hormone release o Involved in drive related behaviors and maintenance of homeostasis Feeding drinking temperature regulation sexual behavior fighting arousal activity level sleep wake rhythms o Makes and secretes melatonin o Daily and seasonal rhythms o Under the right side of the corpus callosum Pineal gland Pituitary gland Basal ganglia o Several interconnected structures deep to cortex o Facilitate or inhibit cortical activity o Motor control damage leads primarily to movement disorders but also memory and emotional expression o Lose substantia nigra Parkinson s Disease o Lose caudate and putamen Huntington s Chorea uncontrollable movements Limbic system o Several interconnected structures most importantly Amygdala emotion and Hippocampus spatial and declarative memory Cortex 2 Hemispheres 4 lobes o Frontal o Parietal o Temporal o Occipital Hemispheres communicate mainly corpus callosum Also communication between parts of cortex within a hemisphere Conscious awareness of sensory stimuli High level of brain activity Gross Anatomy of the Brain 4 1 4 2 September 4 2014 The Lobes of the Cortex Frontal Parietal Temporal Occipital Frontal Lobe Prefrontal cortex executive functions o Planning o Working memory o Socially appropriate behavior o Foresight o Insight o Impulse control o This is called association cortex o Highly evolved in humans Motor Cortex o Voluntary movement o Somatotopic organization homunculus how of the cortex is given to each individual part of body little man o Other motor areas between this and prefrontal cortex Language Broca s area o Much more in one hemisphere than in the other o Motor production of language writing speaking signing Parietal Lobe Somatosensory Cortex much the o First cortex to process somatosensory touch temperature pain info Proprioception too body sense Where the limbs are in space o Somatotopic organization homunculus again Parts of the bodies that feel more get more space on the sensory cortex o Spatial organization understanding where I am to the rest of the world Especially in non dominant hemisphere side where language is not or is less Contralateral neglect Can occur in people that have damage to the parietal lobe Ignore the other side of their world If damage is in the right side they do not see the left side of their world Where pathway for visual info visual information from occipital lobe comes in and it is the job of the parietal lobe to interpret WHERE the visual stimulus is Homunculus Temporal Lobe Auditory cortex Spoken language comprehension o Wernicke s Area Visual association cortex o Face recognition what pathway signals to the temporal lobe to explain WHAT something is i e a bird song means a bird A tumor in temporal lobe can lead to elaborate visual or auditory hallucinations Occipital Lobe Vision The binding problem single self o Primary and secondary visual cortex o Damage causes cortical blindness How do all of these brain and behaviors produce integrated behavior and the experience of a Binding occurs if you perceive 2 sensations happening at the same time and in the same place Used to think associating cortex now not so sure because few cells actually respond to multiple sensory modalities Homework try the mirror thing Meninges 3 layers Stabilize and protect the o Dura mater o Arachnoid o Pia matter o Mechanical o CSF fluid within arachnoid and Cushions Ventricles CNS cerebrospinal meninges b t pia for buoyancy the brain fluid CFS ventricles Contain cerebrospinal CSF is made in walls of CSF then circulates around the brain CSF finally reabsorbed into blood vessels so continuous turnover Protective Reservoir for hormones nutrients Ventricle Size Can indicate Problems Enlarged ventricles as in Alzheimer s patients and other neurodegenerative disease schizophrenia as well Lack of ventricles due to tumors etc Bell Magendie Law The entering dorsal roots carry sensory information to the brain and the exiting ventral roots carry motor information to the muscles and the glands The Spinal cord organizes reflexes Involuntary stereotyped response to the sensory input Stretch reflex o Muscle contraction in response to stretch o Monosynaptic Structures of the Vertebrate Nervous System Chapter 4 1 Terminology to Describe the Nervous System Central nervous system the brain and the spinal cord Peripheral nervous system connects the brain and spinal cord to the rest of the body o Somatic nervous system part of the PNS consists of the axons conveying messages from the sense organs to the CNS and from the CNS to the muscles o Autonomic nervous system
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