BIOLOGY CONCEPTS & CONNECTIONS Fourth Edition Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Neil A. Campbell Jane B. Reece Lawrence G. Mitchell Martha R. Taylor From PowerPoint ® Lectures for Biology: Concepts & Connections CHAPTER 28 Nervous Systems Modules – 28.20

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The vertebrate brain evolved by the enlargement and subdivision of three anterior bulges of the neural tube –Forebrain –Midbrain –Hindbrain Cerebrum size and complexity in birds and mammals correlates with sophisticated behavior The vertebrate brain develops from three anterior bulges of the neural tube THE HUMAN BRAIN

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure Embryonic Brain Regions Brain Structures Present in Adult Forebrain Cerebrum (cerebral hemispheres; includes cerebral cortex, white matter, basal ganglia) Diencephalon (thalamus, hypothalamus, posterior pituitary, pineal gland) Midbrain (part of brainstem)Midbrain Hindbrain Pons (part of brainstem), cerebellum Medulla oblongata (part of brainstem) Midbrain Hindbrain Forebrain Cerebral hemisphere Diencephalon Midbrain Pons Cerebellum Medulla oblongata Spinal cord Embryo one month oldFetus three months old

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The structure of a living supercomputer: The human brain Table 28.15

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 28.15A Forebrain Cerebrum Thalamus Hypothalamus Pituitary gland Midbrain Hindbrain Pons Medulla oblongata Cerebellum Spinal cord Cerebral cortex

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Most of the cerebrum’s integrative power resides in the cerebral cortex of the two cerebral hemispheres Figure 28.15B Left cerebral hemisphere Right cerebral hemisphere Corpus callosum Basal ganglia

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The motor cortex sends commands to skeletal muscles The somatosensory cortex receives information about pain, pressure, and temperature Several regions receive and process sensory information (vision, hearing, taste, smell) The cerebral cortex is a mosaic of specialized, interactive regions

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The association areas are the sites of higher mental activities (thinking) –Frontal association area (judgment, planning) –Auditory association area –Somatosensory association area (reading, speech) –Visual association area

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure PARIETAL LOBE OCCIPITAL LOBE TEMPORAL LOBE Frontal association area Speech Motor cortex Somatosensory cortex Speech Taste Smell Hearing Auditory association area Somatosensory association area Reading Visual association area Vision FRONTAL LOBE

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings In lateralization, areas in the two hemispheres become specialized for different functions –“Right-brained” vs. “left-brained”

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Much knowledge about the brain has come from individuals whose brains were altered through injury, illness, or surgery –The rod that pierced Phineas Gage’s skull left his intellect intact but altered his personality and behavior Connection: Injuries and brain operations have provided insight into brain function Figure 28.17A

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings A radical surgery called hemispherectomy removes almost half of the brain –It demonstrates the brain’s remarkable plasticity Figure 28.17B

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Sleep and arousal are controlled by –the hypothalamus –the medulla oblongata –the pons –neurons of reticular formation Several parts of the brain regulate sleep and arousal Figure 28.18A Eye Reticular formation Input from touch, pain, and temperature receptors Input from ears Motor output to spinal cord

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings An electroencephalogram (EEG) measures brain waves during sleep and arousal Two types of deep sleep alternate –Slow-wave (delta waves) and REM sleep Figure 28.18B, C Awake but quiet (alpha waves) Awake during intense mental activity (beta waves) Asleep Delta wavesREM sleepDelta waves

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The limbic system is a functional group of integrating centers in the cerebral cortex, thalamus, and hypothalamus It is involved in emotions, memory (short-term and long-term), and learning –The amygdala is central to the formation of emotional memories –The hippocampus is involved in the formation of memories and their recall The limbic system is involved in emotions, memory, and learning

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure Thalamus Hypothalamus Prefrontal cortex Smell Olfactory bulb Amygdala Hippocampus CEREBRUM

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Memory and learning involve structural and chemical changes at synapses –Long-term depression (LTD) –Long-term potentiation (LTP) The cellular changes underlying memory and learning probably occur at synapses

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure Repeated action potentials Synaptic cleft Ca 2+ Cascade of chemical changes Sending neuron 3 Ca 2+ LTP Receiving neuron 2