Cerebral Cortex PDF

Cerebral Cortex Acknowledgement to Dr. Ron Bond and Dr. Corrine Boyea Lindsay Garmirian, PT, DPT, PhD Objectives Locate and describe the function of the cerebral cortex Distinguish lateral hemisphere functions Differentiate functions of the various lobes and structures within the cereb...

Cerebral Cortex Acknowledgement to Dr. Ron Bond and Dr. Corrine Boyea Lindsay Garmirian, PT, DPT, PhD Objectives Locate and describe the function of the cerebral cortex Distinguish lateral hemisphere functions Differentiate functions of the various lobes and structures within the cerebral cortex Compare and contrast normal vs. abnormal function of the brain in relation to structure location External Anatomy of the Central Nervous System Cerebral hemisphere rostral caudal cerebellum pons medulla whole brain – lateral view spinal cord Image design credit Dr. Bon Divisions of the Central Nervous System Cortex (Midbrain) (Medulla) The cortex is the outer layer of the cerebral hemispheres whole brain – medial view  Components of the Brain What is gray matter made up of? What is white matter made up of? 1. Gray Matter 2. White Matter 3. Deep Gray diencephalon midbrain Matter pons 4. Ventricles coronal section of the cerebrum Image design Frontal/coronal view credit  Components of the Brain What is gray matter made up of? Cell bodies What is white matter made up of? 1. Gray Matter Myelinated axons 2. White Matter 3. Deep Gray diencephalon midbrain Matter pons 4. Ventricles coronal section of the cerebrum Image design Frontal/coronal view credit  Components of the Brain 1. cerebral cortex (gray matter) Hemispheres: Grey matter is on 1. Gray Matter outside and white matter is on the inside (for the most 2. White Matter part…) 3. Deep Gray diencephalon 2. Subcortical white matter midbrain Matter pons 4. Ventricles coronal section of the cerebrum Image design cred Frontal/coronal view Dr. Bond  Components of the Brain 1. cerebral cortex (gray matter) 1. Gray Matter 4. ventricle 2. White Matter 3. Deep Gray diencephalon 2. Subcortical white matter midbrain Matter pons 4. Ventricles coronal section of the cerebrum 3. Deep gray matter basal ganglia (basal nuclei) Image design cred Frontal/coronal view Dr. Bond  Basic Organization: Important Landmarks Fig 2.9 Lundy-Ekman Corpus callosum Sagittal view Frontal View diencephalon midbrain pons Internal capsule Frontal view Blumenfeld 6.10 Image design credit Dr. Transverse Basic Organization: Lobes 1. Frontal PARIETAL 2. Parietal FRONTAL 3. Temporal OCCIPITAL 4. Occipital TEMPORAL 5. Limbic 6. Insular whole brain – lateral view Image design credit Dr. Bon Basic Organization: Lobes Limbic system regulates emotion, memory and arousal limbic lobe “limbic PARIETAL FRONTAL system” uuss ccoorrpp uum ss m ccaalllloo OCCIPITAL Limbic lobe “limbic system” TEMPORAL brain hemisphere – sagittal view Image design credit Dr. Bond Figure 2.8 Lundy-Ekman Basic Organization: Lobes sagittal MRI PARIETAL PARIETAL Limbic Limbic FRONTAL FRONTAL OCCIPITAL OCCIPITAL Image design credit Dr. Bon Basic Organization: Lobes PARIETAL FRONTAL Insular lobe helps regulate consciousness, emotion and homeostasis TEMPORAL INSULA (INSULAR LOBE) whole brain – lateral view Image design credit Dr. Bon Basic Organization: Lobes PARIETAL PARIETAL diencephalon diencephalon midbrain midbrain TEMPORAL TEMPORAL pons pons INSULA (INSULAR LOBE) Frontal/coronal view Image design credit Dr. Bon Basic Organization: Sulci & Gyri Gyri (singular gyrus) fissure Sulci (singular sulcus) whole brain – lateral view Image design credit Dr. Bon Basic Organization: Major Sulci of the Cerebrum longitudinal fissure central sulcus PARIETAL FRONTAL OCCIPITAL TEMPORAL lateral fissure whole brain – lateral view Image design credit Dr. Bon Basic Organization: Major Sulci of the Cerebrum parieto-occipital sulcus central sulcus PARIETAL LOBE PARIETAL LOBE FRONTAL LOBE OCCIPITAL FRONTAL LOBE LOBE OCCIPITAL LOBE sagittal MRI calcarine sulcus hemisected brain – sagittal view Image design credit Dr. Bon Basic Organization: Major Gyri of the Cerebrum precentral gyrus central sulcus postcentral gyrus superior parietal lobule r Intraparietal sulcus r io pe su inferior parietal lobule e ddl PARIETAL LOBE i m r FRONTAL LOBE FRONTAL LOBE rio fe in e rior OCCIPITAL OCCIPITALLOBE LOBE sup dle mi d TEMPORAL LOBE fe rior in whole brain – lateral view Image design credit Dr. Bon Basic Organization: Major Gyri of the Cerebrum Superior occipital gyri Lateral/Middle occipital gyri Inferior occipital gyri whole brain – lateral view Image credit: https://en.wikipedia.org/wiki/Occipital_g Basic Organization: Major Gyri of the Cerebrum cingulate gyrus cuneus Cingulate = belt, zone, band cuneus Cuneus = wedge PARIETAL LOBE PARIETAL LOBE Lingula = tongue-like corpus callosum corpus callosum FRONTAL LOBE FRONTAL LOBE OCCIPITAL OCCIPITAL LOBE LOBE calcarine sulcus lingula hemisected brain – sagittal view sagittal MRI calcarine sulcus lingula Image design credit Dr. Bon Basic Organization: Major Gyri of the Cerebrum Uncus = hook uncus parahippocampal gyrus medial medial “hook” “hook” of of parahippocampal parahippocampal gyrus gyrus temporal lobe whole brain= ventral view Image design credit Dr. Bon Cerebral Function: Function of Lobes FRONTAL LOBE Processing visual information Process hearing, memory, emotions, and the PARIETAL LOBE sensory aspects of speech. Functions in sensation; it processes touch, pressure, pain and temperature sensation OCCIPITAL LOBE and proprioception Motor control, cognitive functions, the TEMPORAL LOBE processing of emotions, and the motor aspects of language Cerebral Function: Frontal Lobe In addition to motor control… Restraint Initiative Order (inhibition of inappropriate (motivation to pursue (capacity to correctly behaviors) positive or productive perform sequencing tasks) activities) Judgment Curiosity Abstract reasoning Foresight Motivation Working memory Perseverance Creativity Planning Delaying Shifting cognitive Insight gratification focus Organization Inhibition of Personality Sequencing socially Mental flexibility Temporal order inappropriate behaviors Concentration Blumenfeld, 2010 Cerebral Function: Parietal Lobe Somatosensation: touch, proprioception, vibration, temperature Spatial and visual perception Provide meaning to objects Interpret language and words Discrimination of right vs. left Calculations Body image awareness: naming each finger Written language Complex motor task planning Blumenfeld, 2010 Cerebral Function: Occipital Lobe Visual information Process color, light, shapes Judgment of distances 3D vision Cerebral Function: Temporal Lobe Auditory processing Understanding and production of meaningful speech (Wernicke’s area) Verbal and general memory Olfaction Controlling unconscious and automatic reactions (appetite, thirst, hunger) Aides in maintaining body homeostasis Interpretation of other’s emotions and reactions Formation of visual memories Object recognition Cerebral cortex: Functional Areas Secondar Primary Associati Motor Primary y sensory on planning motor sensory cortex cortex areas cortex cortex Discrimina Performs Controls Organize Provides tes among more behavior, movement descendin different complex interprets s g control intensities analysis of sensation, of motor and sensation processes output qualities of emotions sensory and informatio memories n Cerebral cortex: Functional Areas Primary sensory areas Receive sensory info directly from thalamus Discriminates among different intensities and qualities of one type of input Figure 26.12 Lundy-Ekman Cerebral cortex: Functional Areas Secondary sensory areas Perform more complex analysis of sensation Perception: interpretation of sensation into meaningful forms Stereognosis, Graphesthesia, memory of tactile and spatial environments Stereognosis graphesthesia Figure 26.13 Lundy-Ekman Cerebral cortex: Functional Areas Association areas Control behavior, interpret sensation, processes emotions and memories Higher level information processing Analyze sensory input that results in stimulus being organized into meaningful, recognizable “chunks” Examples Unimodal: somatosensory, visual or auditory association cortex Multimodal: prefrontal cortex, parietal and temporal heteromodal association cortex Lundy-Ekman, Ron Bond, Cerebral cortex: Functional Areas Motor planning areas Primary motor (4) Lesion: Paresis, Organize movement impaired selectivity of movement, dysarthria Movements initiated by external stimuli, visually guided tasks Movements initiated internally, complex tasks, sequences, coordination during bimanual tasks Figure 26.15 Lundy-Ekman Cerebral cortex: Functional Areas Primary motor cortex Primary motor (4) Provides descending control of motor Lesion: Paresis, impaired selectivity of movement, dysarthria output Figure 26.15 Lundy-Ekman Topographical Organization: Homunculus Blumenfeld Figure 2.13 Cortical Information Flow Primary visual Secondary visual Association Premotor Primary motor cortex cortex cortex cortex cortex  Motor Cortex Supplementary motor Premotor Cortex Primary Motor area Cortex Upper motor neuron Alpha motor (Corticospinal tract) neuron Motor Motor Motor Plan Plan ✕ ✕ Plan ✕ Spinal Cord Motor Motor Motor Plan Plan ✕ Plan ✔ ✕ Motor planning Executio n Blumenfeld; image credit cleanpng.com  White matter organization mage credit: https://www.123rf.com Figure 26.7 Lundy-Ekman  Projection, Commissural and Association Fibers Projection Fibers Commissural Fibers Association Fibers Axons that Connect homologous Axons that connect cortical connect cortex areas of cerebral areas within one hemisphere with lower parts hemispheres (cross (don’t cross midline) of brain or spinal midline) Short: connect adjacent gyri cord Ex. Corpus callosum, Long: connect lobes within Ex. Internal anterior and posterior single hemisphere capsule commissures Ex. Cingulum, uncinate Fasciculus, superior and inferior longitudinal fasciculus internal capsule Figure 26.8 Lundy-Ekman Cerebral Function: Brodmann Areas In 1909 Brodmann published a map of the cortex that distinguished 52 histologic areas. Brodmann’s areas continue to be use today to designate cortical locations Lundy-Ekman; Image credit: https://commons.wikimedia.org/ Do not memorize Language: Broca’s and Wernicke’s Areas * Hearing a word and repeating it: Speech production Comprehension of speech Blumenfeld Figure 19.2 Image credit: https://faculty.washington.edu/chudler/lang.htm Broca’s and Wernicke’s Areas: Aphasia * Broca’s / Expressive Wernicke’s / Receptive Aphasia Aphasia Impaired fluency Normal fluency but impaired Comprehension intact meaning Impaired comprehension https://www.youtube https://www.youtube.com/watch?v=J.com/watch?v=3oef WC-cVQmEmY 68YabD0 Apraxia * Deficit in higher order motor planning and execution with intact strength Most often caused by damage to the dominant hemisphere near areas related to motor and language planning (frontal-parietal-temporal) https://www.youtube.com/watch? v=EvOYeqM-6CE Neglect * Inability to register and integrate stimuli and perceptions from one side of the body or environment, which is not due to sensory loss Most often caused by damage to the non-dominant temporoparietal junction or inferior parietal lobe Image credit: https://tactustherapy.com References Course notes, Dr. Ron Bond and Dr. Corrine Boyea Lundy-Ekman L. Neuroscience: Fundamentals for rehabilitation. St. Louis, Mo: Saunders/Elsevier; 2007. Blumenfeld H. Neuroanatomy Through Clinical Cases. Sunderland, Mass.: Sinauer Associates; 2010.  Components of the Brain What is gray matter made up of? Cell bodies What is white matter made up of? Myelinated axons 1. Gray Matter 2. White Matter 3. Deep Gray diencephalon midbrain Matter pons 4. Ventricles coronal section of the cerebrum Image design Frontal/coronal view credit Cerebral Function: Function of Lobes FRONTAL LOBE Processing visual information Process hearing, memory, emotions, and the PARIETAL LOBE sensory aspects of speech. Functions in sensation; it processes touch, pressure, pain and temperature sensation OCCIPITAL LOBE and proprioception Motor control, cognitive functions, the TEMPORAL LOBE processing of emotions, and the motor aspects of language