Nervous System Day 1 Functions of the Nervous

Nervous System Day 1

Functions of the Nervous System § Sensory input—gathering information § Receiving stimuli = sensory function § Changes = stimuli § To monitor changes occurring inside and outside the body § Integration § Deciding about stimuli = integrative function § To process and interpret sensory input and decide if action is needed Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

Functions of the Nervous System § Motor output § A response to integrated stimuli § The response activates muscles or glands Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

Functions of the Nervous System Figure 7. 1 Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

Functions of Nervous System • Sensory Function • Sensory receptors gather information • Information is carried to the CNS • Integrative Function • Sensory information used to create: • Sensations • Memory • Thoughts • Decisions • Motor Function • Decisions are acted upon • Impulses are carried to effectors 5

Structural Classification of the Nervous System § What is the brain made out of? How much does it weigh? § _____ nervous System (CNS) § _____ § Spinal ______ § _____ nervous system (PNS) § Nerves outside the brain and spinal cord § Spinal ______ § _______ nerves Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

Divisions of the Nervous System Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

Functional Classification of the Peripheral Nervous System § Sensory (afferent) division § Nerve fibers that carry information to the _______ nervous system § Picks up sensory information and delivers it to the CNS § Motor (efferent) division § Nerve fibers that carry impulses away from the central nervous system § Carries information to muscles and ____ Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

Functional Classification of the Peripheral Nervous System § Motor (efferent) division (continued)- motor functions of the peripheral nervous system fall into two categories voluntary or _______. § Two subdivisions § Somatic nervous system = motor functions under voluntary control involve this system. (Skeletal muscle) § carries information to skeletal muscle § Autonomic nervous system = involuntary § carries information to smooth muscle, cardiac muscle, and glands Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

Organization of the Nervous System Figure 7. 2 Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

Divisions Nervous System Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Central Nervous System (brain and spinal cord) Brain Peripheral Nervous System (cranial and spinal nerves) Cranial nerves Sensory division Spinal cord Sensory receptors Spinal nerves Motor division Somatic Nervous System Skeletal muscle Autonomic Nervous System Smooth muscle Cardiac muscle Glands 11 (a) (b)

10. 3: Description of Cells of the Nervous System • Cell of the nervous system- Neuron • Neurons vary in size and shape • They may differ in length and size of their axons and dendrites • Neurons share certain features: • Dendrites • A cell body • An axon 12

Nervous Tissue: Neurons § Processes (arm-like) outside the cell body § Dendrites—conduct impulses toward the _______ body § Axons—conduct impulses away from the _______ body Copyright © 2009 Pearson Education, Inc. , publishing as Benjamin Cummings

Neuron Structure Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Chromatophilic substance (Nissl bodies) Dendrites Cell body Nucleus Nucleolus Neurofibrils Axonal hillock Impulse Axon Synaptic knob of axon terminal Nodes of Ranvier Myelin (cut) Axon Nucleus of Schwann cell Portion of a collateral 14