CHAPTER 12 CENTRAL NERVOUS SYSTEM

1 Copyright 2010 Pearson Education, Inc. CHAPTER 12 CENTRAL NERVOUS SYSTEM Copyright 2010 Pearson Education, Inc. CENTRAL NERVOUS SYSTEM Embryonic Development Copyright 2010 Pearson Education, Inc. Figure Development of the neural tube from embryonic ectoderm (1 of 4). 1 The neural plate forms from surface ectoderm. Head Tail Surface ectoderm Neural plate Copyright 2010 Pearson Education, Inc. Figure Development of the neural tube from embryonic ectoderm (2 of 4). 2 The neural plate invaginates, forming the neural groove, flanked by neural folds. Neural folds Neural groove Copyright 2010 Pearson Education, Inc.

2 Figure Development of the neural tube from embryonic ectoderm (3 of 4). 3 Neural fold cells migrate to form the neural crest, which will form much of the PNS and many other structures. Neural crest Copyright 2010 Pearson Education, Inc. Figure Development of the neural tube from embryonic ectoderm (4 of 4). Surface ectoderm Head Tail Neural tube 4 The neural groove becomes the neural tube, which will form CNS structures. Copyright 2010 Pearson Education, Inc. Neural tube formation involves all of these stages 1)Neural plate 2)Neural ring 3)Neural groove 4)Surface ectoderm 5)Neural tube Copyright 2010 Pearson Education, Inc.

3 Figure Embryonic development of the human brain. (e) Adult neural canal regions (d) Adult brain structures (a) Neural tube (c) Secondary brain vesicles (b) Primary brain vesicles Anterior (rostral) Posterior (caudal) Spinal cord Cerebellum Brain stem: medulla oblongata Brain stem: pons Brain stem: midbrain Diencephalon (thalamus, hypothalamus, epithalamus), retina Cerebrum: cerebral hemispheres ( cortex , white matter, basal nuclei) Myelencephalon Metencephalon Mesencephalon Diencephalon Telencephalon Rhombencephalon (hindbrain) Mesencephalon (midbrain) Prosencephalon (forebrain) CENTRAL canal Fourth ventricle Cerebral aqueduct Third ventricle Lateral ventricles Copyright 2010 Pearson Education, Inc.

4 Which of these adult brain structures is derived from the prosencephalon? 1)Brain stem 2)Cerebellum 3)Cerebrum 4)All of the above Copyright 2010 Pearson Education, Inc. CENTRAL NERVOUS SYSTEM Regions and Organization Copyright 2010 Pearson Education, Inc. Figure Effect of space restriction on brain development. Cerebellum Diencephalon Cerebral hemisphere (d) Birth Brain stem Midbrain Pons Medulla oblongata Copyright 2010 Pearson Education, Inc. Figure Pattern of gray and white matter in the CNS (highly simplified). Cerebrum Cerebellum Migratory pattern of neurons cortex of gray matter Inner gray matter Gray matter Outer white matter CENTRAL cavity CENTRAL cavity Inner gray matter Gray matter Outer white matter CENTRAL cavity Inner gray matter Outer white matter Region of cerebellum Brain stem Spinal cord Copyright 2010 Pearson Education, Inc.

5 CENTRAL NERVOUS SYSTEM Ventricles Copyright 2010 Pearson Education, Inc. Figure Ventricles of the brain. Anterior horn Interventricular foramen Inferior horn Lateral aperture (b) Left lateral view Lateral ventricle Septum pellucidum Third ventricle Cerebral aqueduct (a) Anterior view Fourth ventricle CENTRAL canal Inferior horn Posterior horn Median aperture Lateral aperture Copyright 2010 Pearson Education, Inc. White matter 1)High density areas of neuron cell bodies 2)Muscle 3)Blood vessels 4)High density areas of unmyelinated axons 5)High density areas of myelinated axons Copyright 2010 Pearson Education, Inc. True or false: The CENTRAL canal of the spinal Cord is continuous with the ventricles of the Brain.

6 1)True 2)False Copyright 2010 Pearson Education, Inc. CENTRAL NERVOUS SYSTEM Cerebral Hemispheres: Cerebral cortex Copyright 2010 Pearson Education, Inc. Figure Lobes and fissures of the cerebral hemispheres. Postcentral gyrus CENTRAL sulcus Precentral gyrus Frontal lobe (a) Parietal lobe Parieto-occipital sulcus (on medial surface of hemisphere) Lateral sulcus Transverse cerebral fissure Occipital lobe Temporal lobe Cerebellum Pons Medulla oblongata Spinal cord cortex (gray matter) Fissure (a deep sulcus) Gyrus Sulcus White matter Copyright 2010 Pearson Education, Inc. Figure Lobes and fissures of the cerebral hemispheres.

7 CENTRAL sulcus (b) Frontal lobe Temporal lobe (pulled down) Gyri of insula Copyright 2010 Pearson Education, Inc. Figure Lobes and fissures of the cerebral hemispheres. Parietal lobe Frontal lobe Right cerebral hemisphere Occipital lobe Left cerebral hemisphere Cerebral veins and arteries covered by arachnoid mater Longitudinal fissure Posterior (c) Anterior Copyright 2010 Pearson Education, Inc. Figure Functional neuroimaging (fMRI) of the cerebral cortex . CENTRAL sulcus Longitudinal fissure Left frontal lobe Left temporal lobe Areas active in speech and hearing (fMRI) Copyright 2010 Pearson Education, Inc. Figure Functional and structural areas of the cerebral cortex .

8 Gustatory cortex (in insula) Primary motor cortex Premotor cortex Frontal eye field Working memory for spatial tasks Executive area for task management Working memory for object-recall tasks Broca s area (outlined by dashes) Solving complex, multitask problems (a) Lateral view, left cerebral hemisphere Motor areas prefrontal cortex Sensory areas and related association areas CENTRAL sulcus Primary somatosensory cortex Somatosensory association cortex Somatic sensation Taste Wernicke s area (outlined by dashes) Primary visual cortex Visual association area Vision Auditory association area Primary auditory cortex Hearing Primary motor cortex Motor association cortex Primary sensory cortex Sensory association cortex Multimodal association cortex Copyright 2010 Pearson Education, Inc.

9 Figure Functional and structural areas of the cerebral cortex . Frontal eye field prefrontal cortex Processes emotions related to personal and social interactions (b) Parasagittal view, right hemisphere Olfactory bulb Orbitofrontal cortex Olfactory tract Fornix Temporal lobe Corpus callosum Premotor cortex Primary motor cortex Cingulate gyrus CENTRAL sulcus Primary somatosensory cortex Parietal lobe Parieto-occipital sulcus Somatosensory association cortex Occipital lobe Visual association area Calcarine sulcus Parahippocampal gyrus Uncus Primary olfactory cortex Primary visual cortex Primary motor cortex Motor association cortex Primary sensory cortex Sensory association cortex Multimodal association cortex Copyright 2010 Pearson Education, Inc.

10 Figure Body maps in the primary motor cortex and somatosensory cortex of the cerebrum. Genitals Toes Intra- abdominal Swallowing Tongue Jaw Primary motor cortex (precentral gyrus) Primary somato- sensory cortex (postcentral gyrus) Motor Motor map in precentral gyrus Sensory Sensory map in postcentral gyrus Posterior Anterior Copyright 2010 Pearson Education, Inc. Quiz Q1: All of these are true of the primary motor cortex except 1)Is located anterior to the CENTRAL sulcus 2)Is located on the precentral gyrus 3)Controls voluntary muscle movement 4)Coordinates repeated/learned complex muscle movements Copyright 2010 Pearson Education, Inc.