Write this down…

 Homework 2 Study Guide (Synapses)  Due at the beginning of lab this week  Front and back  TASS  M&W 1-2pm Willamette Hall 204

Thought Question…

 When you have one of your mandibular teeth worked on at the dentist and he gives you a shot to deaden half of your mouth, what division of the nervous system is being affected by the lidocaine?  What do you think it’s mode of action is?  Hint: Remember Physio-EX in lab?  Is it affecting a cranial or spinal nerve? The Nervous System

THE CENTRAL NERVOUS SYSTEM, T H E B R A I N

Introduction

 Integration  Memory  Learning  Sensation and perception

Neural Tissue - Definitions

 White matter versus Gray matter

 Fiber Bundles  Nerves versus Tracts

 Nerve Cell Bodies  Nucleus versus Ganglion

White and Gray Matter

 Central cavity surrounded by a gray matter core  External white matter composed of myelinated fiber tracts  Brain has additional areas of gray matter not present in spinal cord Central cavity Cortex of gray matter Migratory Inner gray pattern of matter neurons Cerebrum Outer white Cerebellum matter Gray matter Region of cerebellum Central cavity Inner gray matter Outer white matter

Gray matter Brain stem

Central cavity Outer white matter Inner gray matter Spinal cord

Copyright © 2010 Pearson Education, Inc. Figure 12.4 Brain Similar pattern with additional areas of gray matter The Brain

 Conscious perception  Internal regulation

 Average adult male 3.5 lbs Same brain mass  Average adult female 3.2 lbs to body mass ratio!

Brain Regions

 4 Adult brain regions 1. Cerebral hemispheres (cerebrum) 2. Diencephalon 3. Cerebellum 4. Brain stem (midbrain, pons, and medulla) Brain Regions

Figure 12.3d Ventricles

 Four major regions are connected by ventricles and aqueducts

Figure 12.5 Ventricles

 Filled with cerebrospinal fluid  Lined by ependymal cells  Continuous with one another Cerebrum

 Cerebral hemispheres form superior part of brain  About %80 of brain mass  3 tissue layers  Superficial cortex, gray matter  Internal white matter  Basal nuclei, islands of gray matter Anterior

Longitudinal Frontal lobe fissure

Cerebral veins and arteries Parietal covered by lobe arachnoid mater Left cerebral Right cerebral hemisphere hemisphere Occipital lobe (c) Posterior

Figure 12.6c Cerebral Cortex

 Surface layer of cerebrum  ―Executive Suite‖  Convolutions  Gyri – elevated ridges  Sulci – shallow grooves  Fissures – deep grooves, separate larger regions of the brain Cerebrum

 Fissures divide cerebral hemispheres into 4 lobes Functional Areas of the Cerebral Cortex

 The three types of functional areas are:  Motor areas—control voluntary movement  Sensory areas—conscious awareness of sensation  Association areas—integrate diverse information  Contralateral orientation  Hemispheres are functionally specialized  Conscious behavior involves the entire cortex

Cerebral Motor Activity

Motor areas Central sulcus Sensory areas and related Primary motor cortex association areas Premotor cortex Primary somatosensory cortex Frontal eye field Somatic Somatosensory sensation association cortex Broca’s area Gustatory cortex (outlined by dashes) Taste (in insula) Prefrontal cortex Working memory Wernicke’s area for spatial tasks (outlined by dashes) Executive area for task management Working memory for Primary visual cortex object-recall tasks Vision Solving complex, Visual multitask problems association area Auditory association area Hearing Primary auditory cortex (a) Lateral view, left cerebral hemisphere

Primary motor cortex Motor association cortex Primary sensory cortex Sensory association cortex Multimodal association cortex

Figure 12.8a Primary Motor Cortex

 Large pyramidal cells of the precentral gyrus  Long axons  pyramidal (corticospinal) tracts  Allows conscious control of precise, skilled, voluntary movements  Motor homunculi: upside-down caricatures representing the motor innervation of body regions Motor Homunculus Somatotopy of precentral Posterior gyrus (primary motor cortex)

Motor Motor map in Anterior precentral gyrus

Toes

Jaw

Tongue Primary motor cortex Swallowing (precentral gyrus)

Figure 12.9 Premotor Cortex

 Anterior to the precentral gyrus (primary motor cortex)  Controls learned, repetitious, or patterned motor skills  Coordinates simultaneous or sequential actions  Involved in the planning of movements that depend on sensory feedback Broca’s Area

 Anterior to the inferior region of the premotor area  Present in one hemisphere (usually the left)  A motor speech area that directs muscles of the tongue  Is active as one prepares to speak Frontal Eye Field

 Anterior to the premotor cortex and superior to Broca’s area  Controls voluntary eye movements Cerebral Motor Activity

Motor areas Central sulcus Sensory areas and related Primary motor cortex association areas Premotor cortex Primary somatosensory cortex Frontal eye field Somatic Somatosensory sensation association cortex Broca’s area Gustatory cortex (outlined by dashes) Taste (in insula) Prefrontal cortex Working memory Wernicke’s area for spatial tasks (outlined by dashes) Executive area for task management Working memory for Primary visual cortex object-recall tasks Vision Solving complex, Visual multitask problems association area Auditory association area Hearing Primary auditory cortex (a) Lateral view, left cerebral hemisphere

Primary motor cortex Motor association cortex Primary sensory cortex Sensory association cortex Multimodal association cortex

Figure 12.8a Cerebral Vascular Accident (Stroke)

 Types  Ischemic stroke  Hemorrhagic stroke

 Result  Tissue death called an infarct  Effects are determined by where and how large an area is involved

Stroke cont. Stroke cont.

Cerebral Sensory Activity Sensory areas and related Motor areas Central sulcus Primary motor cortex association areas Premotor cortex Primary somatosensory cortex Frontal eye field Somatic Somatosensory sensation association cortex Broca’s area Gustatory cortex (outlined by dashes) Taste (in insula) Prefrontal cortex Working memory Wernicke’s area for spatial tasks (outlined by dashes) Executive area for task management Working memory for Primary visual cortex object-recall tasks Vision Solving complex, Visual multitask problems association area Auditory association area Hearing Primary auditory cortex (a) Lateral view, left cerebral hemisphere

Primary motor cortex Motor association cortex Primary sensory cortex Sensory association cortex Multimodal association cortex

Figure 12.8a Cerebral Sensory Activity

 Widely dispersed  Parietal, temporal, and occipital lobes  Concerned with conscious awareness of sensation Primary Somatosensory Cortex

 In the postcentral gyri, parietal lobe  Stimuli from skin, skeletal muscles, and joints  Capable of spatial discrimination: identification of body region being stimulated Posterior

Sensory Anterior Sensory map in postcentral gyrus

Genitals

Primary somato- sensory cortex Intra- (postcentral gyrus) abdominal

Copyright © 2010 Pearson Education, Inc. Figure 12.9 Somatosensory Association Cortex

 Posterior to the primary somatosensory cortex  Integrates sensory input from primary somatosensory cortex  Integrates and analyzes inputs such as: temperature, size, texture, and relationship of parts of objects being felt  Keys in pocket

Visual Areas

 Primary Visual Cortex  Occipital lobe  Receives visual information from the retinas  Visual Association Area  Surrounds the primary visual cortex  Uses past visual experiences to interpret visual stimuli (e.g., color, form, and movement)  Complex processing involves entire posterior half of the hemispheres

Auditory Areas

 Primary Auditory Cortex  Temporal lobes  Interprets information from inner ear (pitch, loudness, and location)  Auditory Association Area  Located posterior to the primary auditory cortex  Stores memories of sounds and permits perception of sounds Cerebral Sensory Activity

Sensory areas and related Motor areas Central sulcus Primary motor cortex association areas Premotor cortex Primary somatosensory cortex Frontal eye field Somatic Somatosensory sensation association cortex Broca’s area Gustatory cortex (outlined by dashes) Taste (in insula) Prefrontal cortex Working memory Wernicke’s area for spatial tasks (outlined by dashes) Executive area for task management Working memory for Primary visual cortex object-recall tasks Vision Solving complex, Visual multitask problems association area Auditory association area Hearing Primary auditory cortex (a) Lateral view, left cerebral hemisphere

Primary motor cortex Motor association cortex Primary sensory cortex Sensory association cortex Multimodal association cortex

Figure 12.8a Association Areas

 Receive inputs from multiple sensory areas  Send outputs to multiple areas, including the premotor cortex  Allow us to give meaning to information received, store it as memory, compare it to previous experience, and decide on action to take  Multimodal Association Areas Multimodal Association Areas

 Three areas  Prefrontal Cortex  Posterior Association Area (not discussed here)  Limbic Association Area Cerebral Association Activity

Sensory areas and related Motor areas Central sulcus Primary motor cortex association areas Premotor cortex Primary somatosensory cortex Frontal eye field Somatic Somatosensory sensation association cortex Broca’s area Gustatory cortex (outlined by dashes) Taste (in insula) Prefrontal cortex Working memory Wernicke’s area for spatial tasks (outlined by dashes) Executive area for task management Working memory for Primary visual cortex object-recall tasks Vision Solving complex, Visual multitask problems association area Auditory association area Hearing Primary auditory cortex (a) Lateral view, left cerebral hemisphere

Primary motor cortex Motor association cortex Primary sensory cortex Sensory association cortex Multimodal association cortex

Figure 12.8a Prefrontal Cortex

 Most complicated cortical region  Involved with intellect, cognition, recall, and personality  Contains working memory needed for judgment, reasoning, persistence, and conscience  Development depends on feedback from social environment Limbic Association Area

 Part of the limbic system  Provides emotional impact that helps establish memories  Connections with prefrontal cortex regulate emotional expression Cerebral Association Activity

Sensory areas and related Motor areas Central sulcus Primary motor cortex association areas Premotor cortex Primary somatosensory cortex Frontal eye field Somatic Somatosensory sensation association cortex Broca’s area Gustatory cortex (outlined by dashes) Taste (in insula) Prefrontal cortex Working memory Wernicke’s area for spatial tasks (outlined by dashes) Executive area for task management Working memory for Primary visual cortex object-recall tasks Vision Solving complex, Visual multitask problems association area Auditory association area Hearing Primary auditory cortex (a) Lateral view, left cerebral hemisphere

Primary motor cortex Motor association cortex Primary sensory cortex Sensory association cortex Multimodal association cortex

Figure 12.8a Cerebral Lateralization

 Left hemisphere  Right hemisphere  Math  Visual-spatial skills  Logic  Intuition  Language  Emotion  Controls right side of body  Art and music  Controls left side of body Cerebral White Matter

 Projection tracts  Connect cerebrum w/other body locations  Association tracts  Interconnect cerebral cortex (same side)  Commissural tracts  Connect two hemispheres White Matter Tracts

Figure 12.10 Basal Nuclei

 An association of grey matter deep in cerebral hemispheres  Contribute to muscle coordination by excitatory innervation  Ex. Parkinson’s Basal Nuclei Questions?