Lecture Human anatomy and physiology - Chapter 12: The central nervous system (part a)

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Chapter 12 - The central nervous system (part a), the topics discussed in this chapter are: Central Nervous System (CNS), embryonic development, effect of space restriction on brain development, regions and organization of the CNS, ventricles of the brain,...and other contents.

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Nội dung Text: Lecture Human anatomy and physiology - Chapter 12: The central nervous system (part a)

PowerPoint® Lecture Slides prepared by Janice Meeking, Mount Royal College CHAPTER 12 The Central Nervous System: Part A Copyright © 2010 Pearson Education, Inc.
Central Nervous System (CNS) • CNS consists of the brain and spinal cord • Cephalization • Evolutionary development of the rostral (anterior) portion of the CNS • Increased number of neurons in the head • Highest level is reached in the human brain Copyright © 2010 Pearson Education, Inc.
Embryonic Development • Neural plate forms from ectoderm • Neural plate invaginates to form a neural groove and neural folds Copyright © 2010 Pearson Education, Inc.
Surface Head ectoderm Neural plate Tail 1 The neural plate forms from surface ectoderm. Copyright © 2010 Pearson Education, Inc. Figure 12.1, step 1
Neural folds Neural groove The neural plate invaginates, forming the neural 2 groove, flanked by neural folds. Copyright © 2010 Pearson Education, Inc. Figure 12.1, step 2
Embryonic Development • Neural groove fuses dorsally to form the neural tube • Neural tube gives rise to the brain and spinal cord Copyright © 2010 Pearson Education, Inc.
Neural crest 3 Neural fold cells migrate to form the neural crest, which will form much of the PNS and many other structures. Copyright © 2010 Pearson Education, Inc. Figure 12.1, step 3
Head Surface ectoderm Neural tube Tail 4 The neural groove becomes the neural tube, which will form CNS structures. Copyright © 2010 Pearson Education, Inc. Figure 12.1, step 4
Embryonic Development • Anterior end of the neural tube gives rise to three primary brain vesicles • Prosencephalon—forebrain • Mesencephalon—midbrain • Rhombencephalon—hindbrain Copyright © 2010 Pearson Education, Inc.
(a) (b) Primary brain Neural vesicles tube Anterior Prosencephalon (rostral) (forebrain) Mesencephalon (midbrain) Rhombencephalon (hindbrain) Posterior (caudal) Figure 12.2a-b Copyright © 2010 Pearson Education, Inc.
Embryonic Development • Primary vesicles give rise to five secondary brain vesicles • Telencephalon and diencephalon arise from the forebrain • Mesencephalon remains undivided • Metencephalon and myelencephalon arise from the hindbrain Copyright © 2010 Pearson Education, Inc.
Embryonic Development • Telencephalon cerebrum (two hemispheres with cortex, white matter, and basal nuclei) • Diencephalon thalamus, hypothalamus, epithalamus, and retina Copyright © 2010 Pearson Education, Inc.
Embryonic Development • Mesencephalon brain stem (midbrain) • Metencephalon brain stem (pons) and cerebellum • Myelencephalon brain stem (medulla oblongata) • Central canal of the neural tube enlarges to form fluid-filled ventricles Copyright © 2010 Pearson Education, Inc.
(c) Secondary brain (d) Adult brain (e) Adult vesicles structures neural canal regions Cerebrum: cerebral Lateral Telencephalon hemispheres (cortex, ventricles white matter, basal nuclei) Diencephalon Diencephalon (thalamus, hypothalamus, Third ventricle epithalamus), retina Cerebral Mesencephalon Brain stem: midbrain aqueduct Metencephalon Brain stem: pons Cerebellum Fourth ventricle Myelencephalon Brain stem: medulla oblongata Spinal cord Central canal Copyright © 2010 Pearson Education, Inc. Figure 12.2c-e
Effect of Space Restriction on Brain Development • Midbrain flexure and cervical flexure cause forebrain to move toward the brain stem • Cerebral hemispheres grow posteriorly and laterally • Cerebral hemisphere surfaces crease and fold into convolutions Copyright © 2010 Pearson Education, Inc.
Anterior (rostral) Posterior (caudal) Metencephalon Mesencephalon Midbrain Diencephalon Flexures Cervical Telencephalon Myelencephalon Spinal cord (a) Week 5 Copyright © 2010 Pearson Education, Inc. Figure 12.3a
Cerebral hemisphere Outline of diencephalon Midbrain Cerebellum Pons Medulla oblongata Spinal cord (b) Week 13 Copyright © 2010 Pearson Education, Inc. Figure 12.3b
Cerebral hemisphere Cerebellum Pons Medulla oblongata (c) Week 26 Spinal cord Copyright © 2010 Pearson Education, Inc. Figure 12.3c
Regions and Organization of the CNS • Adult brain regions 1. Cerebral hemispheres 2. Diencephalon 3. Brain stem (midbrain, pons, and medulla) 4. Cerebellum Copyright © 2010 Pearson Education, Inc.
Cerebral hemisphere Diencephalon Cerebellum Brain stem • Midbrain • Pons • Medulla (d) Birth oblongata Copyright © 2010 Pearson Education, Inc. Figure 12.3d