Slide 1Comparative analysisAnatomical referenceAnatomical referenceprotecting the nervous systemprotecting the nervous systemMajor divisions of the nervous systemThe peripheral nervous systemThe peripheral nervous systemThe Peripheral Nervous system: The Cranial nervesThe peripheral nervous system: Spinal nervesThe peripheral nervous system: Autonomic nervous systemThe peripheral nervous system: Autonomic nervous systemThe peripheral nervous system: Autonomic nervous systemThe CENTRAL nervous systemThe CENTRAL nervous system: The brainThe Central nervous system: The brainThe CENTRAL nervous system: The brainThe CENTRAL nervous system: The brainThe CENTRAL nervous system: The brainThe CENTRAL nervous system: The brainThe Central nervous system: Spinal cordThe Central nervous system: spinal cordSlide 24THE STRUCTURE OF THE NERVOUS SYSTEMNEUR 3000Dr. Joseph J. NormandinCOMPARATIVE ANALYSISANATOMICAL REFERENCEANATOMICAL REFERENCEPROTECTING THE NERVOUS SYSTEMPROTECTING THE NERVOUS SYSTEMMAJOR DIVISIONS OF THE NERVOUS SYSTEM•There are two major subdivisions of the nervous system•The central nervous system (CNS): brain and spinal cord•The peripheral nervous system (PNS): all the nerves of the bodyTHE PERIPHERAL NERVOUS SYSTEM•The peripheral nervous system consist of nerves (bundles of axons) and ganglia (clusters of cell bodies) and has three components•Cranial nerves (somatic nervous system)•Nerves of the head/neck region•Connected to the brain•Spinal nerves (somatic nervous system)•Nerves of the rest of the body•Connected to spinal cord•Autonomic nervous system•Controls glands and internal organsTHE PERIPHERAL NERVOUS SYSTEM•Each component of the peripheral nervous system has both a motor and sensory pathways•Sensory pathways travel from the body to the CNS•Motor pathways travel from the CNS to muscles/glands•Ganglia/nerves•Ganglia: collections of cell bodies•Nerves: bundles of axons in the same orientationTHE PERIPHERAL NERVOUS SYSTEM:THE CRANIAL NERVESTHE PERIPHERAL NERVOUS SYSTEM:SPINAL NERVES•The spinal nerves•31 pairs•Each nerve has two branches•Sensory branch enters spinal cord via dorsal root•Motor branch exits spinal cord via ventral root•Named for the segment of spinal cord to which they are connected •Cervical C1-C8•Thoracic T1-T12•Lumbar L1-L5•Sacral S1-S5•CoccygealTHE PERIPHERAL NERVOUS SYSTEM:AUTONOMIC NERVOUS SYSTEM•The autonomic nervous system•Originally thought to act independently of the brain•Primarily peripheral with a central component•Controls unconscious and visceral function•Modulates breathing, heart rate•Modulates digestion•Genital engorgementTHE PERIPHERAL NERVOUS SYSTEM:AUTONOMIC NERVOUS SYSTEM•The autonomic nervous system•Three subdivisions•Sympathetic nervous system•Readies body for activity•Parasympathetic nervous system•Returns body to rest•Enteric nervous system•A neural network in the gut•Innervated by sympathetic and parasympathetic nervous system•Has spontaneous activityTHE PERIPHERAL NERVOUS SYSTEM:AUTONOMIC NERVOUS SYSTEMTHE CENTRAL NERVOUS SYSTEM•The central nervous system consists of the brain and spinal cord•Important features of the central nervous system•Gray/white matter•Gray matter: cell bodies•White matter: axons (often myelinated)•Nuclei/tracts•Nuclei: discrete collections of cell bodies•Tract: a bundle of axons traveling in the same orientationTHE CENTRAL NERVOUS SYSTEM:THE BRAIN•The brain is the executive control center of the nervous system•Comprised of cortex separated into lobes with gyri/sulci and subcortical structures embedded deep in the brain•Subcortical structures•Often share much in common with other animals•Important influences on all cortical function•Origin of unconscious function•Cortex•Most recently evolved portion of the nervous system •Complex cognition•Neurons are arranged in cortical columns with distinct layers•Each column serves as a unit to process informationTHE CENTRAL NERVOUS SYSTEM:THE BRAINTHE CENTRAL NERVOUS SYSTEM:THE BRAINTHE CENTRAL NERVOUS SYSTEM:THE BRAINTHE CENTRAL NERVOUS SYSTEM:THE BRAINTHE CENTRAL NERVOUS SYSTEM:THE BRAINTHE CENTRAL NERVOUS SYSTEM:SPINAL CORDTHE CENTRAL NERVOUS SYSTEM: SPINAL CORDANY QUESTIONS?NEUR 3000Dr. Joseph J.