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Chapter 28 Nervous Systems PowerPoint Lectures for Campbell Biology: Concepts & Connections, Seventh Edition Reece, Taylor, Simon, and Dickey © 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko AN OVERVIEW OF ANIMAL NERVOUS SYSTEMS © 2012 Pearson Education, Inc. The evolution of animal nervous systems reflects changes in body symmetry Radially symmetrical animals exhibit a nerve net. Most bilaterally symmetrical animals evolved – cephalization, the concentration of the nervous system at the head end – centralization, a CNS distinct from a PNS. Eyespot Brain Brain Ventral nerve cord Nerve cord Nerve net Neuron Hydra (cnidarian) Transverse nerve Ganglia Insect (arthropod) 28.11 Vertebrate nervous systems are highly centralized In the vertebrates, the central nervous system (CNS) – consists of the brain and spinal cord and © 2012 Pearson Education, Inc. Figure 28.11A Central nervous system (CNS) Brain Spinal cord Cranial nerves Ganglia outside CNS Spinal nerves Peripheral nervous system (PNS) Figure 28.11B Gray matter Brain Cerebrospinal fluid Meninges White matter Central canal Ventricles Central canal of spinal cord Spinal cord Dorsal root ganglion (part of PNS) Spinal nerve (part of PNS) Spinal cord (cross section) THE HUMAN BRAIN © 2012 Pearson Education, Inc. Cerebral cortex (outer region of cerebrum) Cerebrum Forebrain Thalamus Hypothalamus Pituitary gland Midbrain Cerebellum Coordinates body movements; motor coordination; hand-eye coordination Hindbrain Pons Medulla oblongata Cerebellum Spinal cord Cerebral cortex (outer region of cerebrum) Cerebrum Forebrain Thalamus Hypothalamus Pituitary gland Brainstem Involuntary functions Midbrain Hindbrain Medulla breathing, circulation, digestion Pons Medulla oblongata Cerebellum Pons breathing Midbrain coordinates input of sensory data to higher brain centers Spinal cord Cerebral cortex (outer region of cerebrum) Cerebrum Forebrain Thalamus Hypothalamus Thalamus Serves as input/output center for sensory data and motor responses Pituitary gland Midbrain Hindbrain Hypothalamus Homeostatic control center; controls hormone secretion by pituitary gland and many other endocrine glands Pons Medulla oblongata Cerebellum Spinal cord Cerebral cortex (outer region of cerebrum) Cerebrum Forebrain Thalamus Hypothalamus Pituitary gland Cerebrum Higher order brain functions Midbrain Hindbrain Pons Medulla oblongata Cerebellum Spinal cord Figure 28.14B Left cerebral hemisphere Right cerebral hemisphere Thalamus Cerebrum Cerebellum Basal nuclei Corpus callosum Medulla oblongata The human brain The cerebrum is – the largest and most complex part of the brain. – Most of the cerebrum’s integrative power resides in the cerebral cortex © 2012 Pearson Education, Inc. The cerebral cortex The cerebral cortex – is less than 5 mm thick and – accounts for 80% of the total human brain mass. Specialized integrative regions of the cerebral cortex include – the motor cortex – somatosensory cortex – centers for vision, hearing, taste, and smell. © 2012 Pearson Education, Inc. Figure 28.15 Frontal lobe Parietal lobe Frontal association area Speech Somatosensory association area Reading Speech Hearing Smell Auditory association area Visual association area Vision Temporal lobe Occipital lobe LE 48-28 Frontal lobe Parietal lobe Toes Lips Jaw Tongue MOTOR CORTEX Genitalia SOMATOSENSORY CORTEX Pharynx Abdominal organs 28.19 The limbic system is involved in emotions, memory, and learning The limbic system is – a functional group of integrating centers in the – cerebral cortex, – thalamus, – hypothalamus – involved in – emotions, – Long-term memory, – learning. © 2012 Pearson Education, Inc. Thalamus Cerebrum Hypothalamus Prefrontal cortex Smell Olfactory bulb Amygdala Emotion center Hippocampus Formation of memories and their recall Changes in brain physiology can produce neurological disorders Many neurological disorders can be linked to changes in brain physiology, including – schizophrenia, – major depression, – Alzheimer’s disease, and – Parkinson’s disease. © 2012 Pearson Education, Inc. 28.12 The peripheral nervous system of vertebrates is a functional hierarchy The PNS can be divided into two functional components: 1. the motor system, mostly voluntary, and 2. the autonomic nervous system, mostly involuntary. © 2012 Pearson Education, Inc. 28.12 The peripheral nervous system of vertebrates is a functional hierarchy The motor nervous system – carries signals to and from skeletal muscles and – mainly responds to external stimuli. The autonomic nervous system – regulates the internal environment and – controls smooth and cardiac muscle and organs – (digestive, cardiovascular, excretory, and endocrine systems) © 2012 Pearson Education, Inc. Figure 28.12A Peripheral nervous system (to and from the central nervous system) Motor system (voluntary and involuntary; to and from skeletal muscles) Autonomic nervous system (involuntary; smooth and cardiac muscles, various glands) Parasympathetic division (“Rest and digest”) Sympathetic division (“Flight and fight”) Enteric division (muscles and glands of the digestive system) Figure 28.12B Sympathetic division Parasympathetic division Brain Eye Dilates pupil Constricts pupil Salivary glands Stimulates saliva secretion Inhibits saliva secretion Lung Relaxes bronchi Constricts bronchi Slows heart Accelerates heart Heart Adrenal gland Spinal cord Liver Stomach Stimulates stomach, pancreas, and intestines Pancreas Stimulates epinephrine and norepinephrine release Stimulates glucose release Inhibits stomach, pancreas, and intestines Intestines Bladder Stimulates urination Inhibits urination Promotes erection of genitalia Promotes ejaculation and vaginal contractions Genitalia