Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Organization of the CNS I
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Phrenology
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Review of the Nervous System MAJOR FUNCTION: COMMUNICATION
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Neuronal Morphology
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Neuronal Synapse
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Glia – the Particular Role of Astrocytes
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Astrocyte
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Astrocytes Help Form the Blood Brain Barrier Basal lamina of the astrocytes + the astrocytic endfeet produce help maintain the BBB. Notice how astrocytes send processes to the external surface of the CNS where the endfeet form the glia limitans externa, which separate the pia mater from the nervous tissue. Gap junctions and desmosomes join the endfeet to form a space between neurons and vascular endothelial cells (Fig. 2.2).
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Schwann cells surrounding a (myelinated) axon:
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings General Orientation Terms Rostral Caudal Posterior Anterior Dorsal Ventral Sagital Horizontal Coronal
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Terms of Orientation:
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Planes of Section: HorizontalTransverse (Coronal) Saggital
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Six regions in the adult brain Cerebrum Diencephalon Mesencephalon Pons Cerebellum Medulla oblongata Brain contains extensive areas of neural cortex Layer of gray matter on the surface of the cerebellum and cerebrum Major regions and landmarks
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Adult Brain
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Adult Brain
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Adult Brain
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings 7 Major Divisions of the CNS
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings A. Spinal Cord Conduit for flow of information from PNS to CNS. Participates directly in body movement control. Processes sensory information from limbs, trunk, and internal organs. Has segmental organization (most like primitive or early developmental NS). Each segment has a pair of nerve roots.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings B. Brainstem and Cerebellum 1.Brainstem = medulla + pons + midbrain. a.‘spinal cord’ for the head (sensory, motor control). -use of cranial nerves in place of spinal nerves. b. Transmission of information between brain and SC. c.Regulation of arousal (via reticular formation at the core of brainstem). d.Regulation of important visceral functions (e.g., bp and respiration).
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Brain Stem: Ventral Surface
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Brain Stem: Dorsal Surface
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings B. Brainstem and Cerebellum 2.Cerebellum – regulation of movement, maintenance of posture and balance. -Works closely in concert with pons (derived from same embryonic brain division).
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Adjusts postural muscles and tunes on-going movements Cerebellar hemispheres Anterior and posterior lobes Vermis Flocculonodular lobe Superior, middle and inferior cerebellar peduncles link cerebellum with brain stem, diencephalon, cerebrum, and spinal cord Interconnects the two cerebellar hemispheres The Cerebellum
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Cerebellum
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Cerebellum
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cerebellum:
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings C. Diencelphalon Diencephalon – 2 nd only to cerebrum as the most highly developed division. 1.Thalamus – key for transmitting information to cerebral hemispheres. 2.Hypothalamus – integrates functions of the ANS – controls endocrine hormone release from pit.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Final relay point for ascending sensory information Coordinates the activities of the cerebral cortex and basal nuclei The Thalamus
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Thalamus Part of diencephalon – relay nuclei through which sensory and motor information pass to and from the cortex. E.g., in the 2 1° systems we have discussed: - from sc 1° sensory cortex - from 1° motor cortex sc. This is also the case for neural signals controlling other functions, such as learning and memory and emotions – and projecting to other parts of the cortex. A. Relay Nuclei have distinct roles, transmitting info from particular subcortical inputs to a specific portion of the cerebral cortex.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Thalamus
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Thalamus:
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Diencephalon and Brain Stem
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Diencephalon and Brain Stem
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings D. Cerebral Hemispheres These structures mediate the most complex and sophisticated human behaviors. 1.Cerebral cortex – highly convoluted to accommodate large surface area: gyri, sulci, fissures – deeper grooves – often separate major divisions. 4 lobes:
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Frontal Motor behavior The 1° cortex at precentral gyrus. -nearby premotor areas -prefrontal asociation cortex -cingulate gyrus - important for reasoning and emotional control.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Parietal Sensory areas. The 1° cortex at postcentral gyrus. -Superior parietal lobule -spatial perception, self-image -Inferior parietal lobule -integrating sensory information for speech and perception
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Occipital The 1° cortex within calcarine fissure on medial surface. Surrounding association cortex elaborates the sensory message so that we can see and integrate forms and colours. Situated at the division of parietal and occipital lobes is an area important for recognizing faces.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Temporal Sensory functions, plus memory and emotions. The 1° auditory cortex: on superior temporal gyrus – speech centre. Much integration with nearby areas: -inferior temporal gyrus – perception of visual forms and colours. - works with nearby occipital. -temporal pole + medial temporal areas – mediate emotions along with nearby frontal cortical areas.
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Central passageway of the brain enlarges to form ventricles Contain cerebrospinal fluid (CSF) Ventricles of the Brain
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Ventricles of the Brain
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Continuous with the three layers of the spinal cord Folds of dura mater help stabilize the position of the brain Falx cerebri Tentorium cerebelli Falx cerebelli The Cranial Meninges
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Meninges of the CNS 3 layers: 1.Dura - thickest 2.Arachnoid – “spider-like” 3.Pia – delicate, adheres to surface. Protective Circulating function (contain blood vessels) – many veins and arteries in subarachnoid space. Dural sinuses are major venous areas carrying blood away from the brain.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Meninges:
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Medulla Oblongata and Pons
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Medulla Oblongata and Pons
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The tectum (roof) contains the corpora quadrigemina Superior and inferior colliculi The mesencephalon contains many nuclei Red nucleus Substantia nigra Cerebral peduncles RAS headquarters The Mesencephalon
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Mesencephalon
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithalamus Hypothalamus Thalamus The Diencephalon is Composed of
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Internal Capsule White matter underling the cortex (seen as a band over the thalamus in sagital section). Path of transmission of info immediate to and from the cortex.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Internal Capsule
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Internal Capsule In the following horizontal section, it lies between the thalamus and the caudate and other basal ganglia (putamen and globus pallidus).
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Controls somatic motor activities at the subconscious level Controls autonomic function Coordinates activities of the endocrine and nervous systems Secretes hormones Produces emotions and behavioral drives Coordinates voluntary and autonomic functions Regulates body temperature Coordinates circadian cycles of activity The Hypothalamus
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Hypothalamus in Sagital Section
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Hypothalamus in Sagital Section
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hypothalamus:
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Caudate nucleus Globus pallidus Putamen Control muscle tone and coordinate learned movement patterns The Basal Nuclei
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Limbic System
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Brain in Section
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Brain in Section
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Surface contains gyri and sulci or fissures Longitudinal fissure separates two cerebral hemispheres Central sulcus separates frontal and parietal lobes Temporal and occipital lobes also bounded by sulci The Cerebral Cortex
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Laminar Organization of the Cerebral Cortex All cortical regions are organized in layers. A.Most cortical regions in humans are the most advanced form (neocortex, isocortex). B.Allocortex – phylogeneticaly older, has fewer layers: 2 types: i. Paleocortex – sense of smell, emotions (olf bulb). ii. Archicortex – memories (hipp, 3 layers)
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Laminar Organization of the Cerebral Cortex C. Brodmann’s Areas – Thickness of each of the 6 layers varies between these areas, which are also distinct functionally. Areas that subserve sensation have a thick layer IV (thalamic n. project here) 1° motor areas have a thick layer V.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The White Matter of the Cerebrum
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Cerebral Hemispheres PLAY
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Control our ability to understand sensory information and coordinate a response Somatic sensory association area Visual association area Somatic motor association area Association areas
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings General interpretive area Receives information from all sensory areas Present only in left hemisphere Speech center Regulates patterns of breathing and vocalization General Interpretive and Speech Areas
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Prefrontal cortex Coordinates information from secondary and special association areas Performs abstract intellectual functions Hemispheric differences Left hemisphere typically contains general interpretive and speech centers and is responsible for language based skills Right hemisphere is typically responsible for spatial relationships and analyses Cortex Functions and Hemispheric Differences
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hemispheric Lateralization PLAY
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings 12 pairs of cranial nerves Each attaches to the ventrolateral surface of the brainstem near the associated sensory or motor nuclei Focus: Cranial Nerves
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Origins of the Cranial Nerves PLAY
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Origins of the Cranial Nerves PLAY
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Origins of the Cranial Nerves PLAY
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Amygdaloid body Cingulated gyrus Parahippocampal gyrus Hippocampus Fornix Functions of the limbic system involved emotions and behavioral drives The Limbic System or Motivational System includes
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Surface contains gyri and sulci or fissures Longitudinal fissure separates two cerebral hemispheres Central sulcus separates frontal and parietal lobes Temporal and occipital lobes also bounded by sulci The Cerebral Cortex
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Contains association fibers Commissural fibers Projection fibers White Matter of the Cerebrum
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Control our ability to understand sensory information and coordinate a response Somatic sensory association area Visual association area Somatic motor association area Association Areas
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings General interpretive area Receives information from all sensory areas Present only in left hemisphere Speech center Regulates patterns of breathing and vocalization General Interpretive and Speech Areas
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Prefrontal cortex Coordinates information from secondary and special association areas Performs abstract intellectual functions Hemispheric differences Left hemisphere typically contains general interpretive and speech centers and is responsible for language based skills Right hemisphere is typically responsible for spatial relationships and analyses Cortex Functions and Hemispheric Differences