The Nervous System Amanda Skipworth Danielle Slagle Jack Harrington Period: 6 What is the Nervous System? Consists of neurons, nerves, nerve impulses, and neuroglial cells Nerves: bundles of axons Nerve impulses: information in electrochemical form Neuroglial cells: provides physical support, insulation, and nutrients for neurons Divided into the central nervous system (CNS) and the peripheral nervous system (PNS) CNS consists of brain and spinal cord PNS consists of other body parts What Are the Functions of the Nervous System? Sensory functions: internal and external changes Integrative functions: decision maker Motor functions: carries out function What is a Neuron? Structural and functional units Transmits information in electrochemical form (nerve impulses) Every neuron includes a cell body, dendrites, and an axon Cell body: rounded area with two extensions Dendrites: receive electrochemical messages Axons: send information in nerve impulse form How are Neurons Classified? Neurons differ in structure, size, and shape of their cell bodies Neurons also vary in function such as: Sensory Interneurons Motor 3 major groups Multipolar Bipolar Unipolar Sensory Neurons Afferent neurons Carry impulses to PNS Dendrites have specialized tips Changes inside or outside body trigger sensory nerves Most unipolar; some bipolar Interneurons Also known as association or internuncial neurons Lie within the brain/spinal cord Multipolar neurons Link to other neurons Transmits impulses from one part of the brain/spinal cord to another Directs incoming sensory impulses Motor Neurons Efferent neurons Multipolar Carry nerve impulses out of the brain/spinal cord to effectors Stimulates muscles and glands Causes reactions What is a Synapse? The junction between any two communicating neurons Not in direct physical contact separated by synaptic cleft Synaptic transmission is a one way process, like a phone call Neurotransmitters carry out synaptic transmission Frontal Lobe Location: Frontal and upper area of the cortex Function: Carries out higher mental processes Thinking Decision making Planning Emotions Parietal Lobe Location: Upper, back part of the cortex Function: Processes sensory information Taste Temperature Touch Occipital Lobe Location: Bottom, back part of the cortex Function: Responsible for processing visual information from the eyes Temporal Lobe Location: Bottom middle part of the cortex; behind the temples Function: Responsible for processing auditory information Cerebellum Location: Lower area of the brain Function: Responsible for balance and coordination of the body Medulla Oblongata Location: Lower part of the brain stem Function: Carries out and regulates life sustaining functions Breathing Swallowing Heart rate The Difference Between CNS and PNS PNS CNS Brain and spinal cord Sensory and motor pathways Involuntary actions Voluntary actions Processes information Carries information to and from CNS and other cells What is the Autonomic Nervous System? Portion of PNS that functions independently without a conscious effort Controls Smooth muscles Cardiac muscle Glands Regulates Heart rate Blood pressure Breathing rate Body temperature What is the Difference Between Sympathetic and Parasympathetic? Sympathetic Fight or flight Controls body’s responses to a threat Sympathetic nerve fibers leave spinal cord Parasympathetic Rest and recover Controls homeostasis Begin in the brainstem What are the Human’s Somatic Senses? Touch and pressure Temperature Free ends of sensory nerve fibers Two sets of free nerve endings Pain Two main types of pain fibers Acute Chronic Relationship Between Sense of Taste and Smell Chemicals in food are detected by taste buds Odorants are detected by sensory neurons located in the nose Olfactory information passes to the orbital cortex, The combination of odor and taste information helps create the perception of flavor Works Cited "Activity: Nervous Energy." Nervous Energy. 1 Jan. 2002. Web. 18 Mar. 2015. "BrainFacts.org." Taste and Smell. 1 Apr. 2012. Web. 18 Mar. 2015. "Led around by Our Noses." The Telegraph. Telegraph Media Group. Web. 18 Mar. 2015. "Neuron to Glia Synapses on Axons?" Pure Pedantry. Science Blogs, 6 Mar. 2007. Web. 18 Mar. 2015. What’s the Difference between a Food’s Taste and Its Flavor?" Web. 18 Mar. 2015.