© 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko PowerPoint Lectures for Campbell Biology: Concepts & Connections, Seventh Edition Reece, Taylor, Simon, and Dickey Chapter 28 Nervous Systems

AN OVERVIEW OF ANIMAL NERVOUS SYSTEMS © 2012 Pearson Education, Inc.

 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. The evolution of animal nervous systems reflects changes in body symmetry Nerve net Neuron Hydra (cnidarian) Eyespot Brain Nerve cord Transverse nerve Brain Ventral nerve cord Ganglia Insect (arthropod)

 In the vertebrates, the central nervous system (CNS) –consists of the brain and spinal cord and Vertebrate nervous systems are highly centralized © 2012 Pearson Education, Inc.

Figure 28.11A Central nervous system (CNS) Peripheral nervous system (PNS) Spinal cord Cranial nerves Ganglia outside CNS Spinal nerves Brain

Figure 28.11B Brain Cerebrospinal fluid Meninges Gray matter White matter Dorsal root ganglion (part of PNS) Spinal nerve (part of PNS) Central canal Spinal cord (cross section) Ventricles Central canal of spinal cord Spinal cord

THE HUMAN BRAIN © 2012 Pearson Education, Inc.

Cerebral cortex (outer region of cerebrum) Cerebrum Thalamus Hypothalamus Pituitary gland Midbrain Forebrain Hindbrain Pons Medulla oblongata Cerebellum Spinal cord Cerebellum Coordinates body movements; motor coordination; hand-eye coordination

Cerebral cortex (outer region of cerebrum) Cerebrum Thalamus Hypothalamus Pituitary gland Midbrain Forebrain Hindbrain Pons Medulla oblongata Cerebellum Spinal cord Brainstem Involuntary functions Medulla breathing, circulation, digestion Pons breathing Midbrain coordinates input of sensory data to higher brain centers

Cerebral cortex (outer region of cerebrum) Cerebrum Thalamus Hypothalamus Pituitary gland Midbrain Forebrain Hindbrain Pons Medulla oblongata Cerebellum Spinal cord Thalamus Serves as input/output center for sensory data and motor responses Hypothalamus Homeostatic control center; controls hormone secretion by pituitary gland and many other endocrine glands

Cerebral cortex (outer region of cerebrum) Cerebrum Thalamus Hypothalamus Pituitary gland Midbrain Forebrain Hindbrain Pons Medulla oblongata Cerebellum Spinal cord Cerebrum Higher order brain functions

Figure 28.14B Left cerebral hemisphere Right cerebral hemisphere Thalamus Basal nuclei Medulla oblongata Corpus callosum Cerebrum Cerebellum

 The cerebrum is –the largest and most complex part of the brain. –Most of the cerebrum’s integrative power resides in the cerebral cortex The human brain © 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 Frontal lobeParietal lobe Occipital lobeTemporal lobe Frontal association area Speech Smell Speech Motor cortex Hearing Reading Vision Visual association area Somatosensory association area Auditory association area Somatosensory cortex

LE Frontal lobeParietal lobe MOTOR CORTEX SOMATOSENSORY CORTEX Genitalia Tongue Jaw Lips Face Neck Eye Brow Shoulder Trunk Hip Wrist Hand Fingers Thumb Forearm Elbow Knee Tongue Jaw Lips Face Eye Head Hand Fingers Thumb Forearm Elbow Abdominal organs Toes Pharynx Gums Teeth Nose Upper arm Neck Trunk Hip Leg

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.

Cerebrum Hippocampus Formation of memories and their recall Amygdala Emotion center Olfactory bulb Thalamus Hypothalamus Prefrontal cortex Smell

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.

 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) The peripheral nervous system of vertebrates is a functional hierarchy © 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 Brain Parasympathetic division Eye Constricts pupil Lung Constricts bronchi Stimulates saliva secretion Stimulates stomach, pancreas, and intestines Salivary glands Sympathetic division Dilates pupil Inhibits saliva secretion Relaxes bronchi Accelerates heart Heart Liver Stomach Adrenal gland Stimulates epinephrine and norepi- nephrine release Pancreas Intestines Bladder Stimulates glucose release Inhibits stomach, pancreas, and intestines Inhibits urination Slows heart Stimulates urination Spinal cord Genitalia Promotes erection of genitalia Promotes ejacu- lation and vaginal contractions