1 / 21

Essentials of Human Anatomy & Physiology

Essentials of Human Anatomy & Physiology. The Nervous System Chapter 7. Nervous System Functions. 1. Sensory input – gathered information Allows you to monitor changes occurring in & outside of the body (changes = stimuli) 2. Integration

adonai
Télécharger la présentation

Essentials of Human Anatomy & Physiology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Essentials of Human Anatomy & Physiology The Nervous System Chapter 7

  2. Nervous System Functions 1. Sensory input – gathered information • Allows you to monitor changes occurring in & outside of the body (changes = stimuli) 2. Integration • Process and interpret the sensory input and decide if action is needed 3. Motor output • A response to integrated stimuli activates muscles or glands

  3. Structural Classification of the Nervous System • Central Nervous System (CNS) • Brain • Spinal cord • Peripheral Nervous System (PNS) • Nerves that extend from the brain and spinal cord

  4. Functional Classification of the Peripheral Nervous System • Sensory (afferent) division • Nerve fibers that carry information to the central nervous system

  5. Functional Classification of the Peripheral Nervous System • Motor (efferent) division • Nerve fibers that carry impulses away from the central nervous system

  6. Functional Classification of the Peripheral Nervous System • Motor (efferent) division • Two subdivisions • Somatic nervous system = Voluntary • Autonomic nervous system = Involuntary • Sympathetic • Parasympathetic

  7. Organization of the Nervous System

  8. Nervous Tissue: Support Cells • Supporting Cells in the CNS • Lumped together as neuroglia (AKA- glia or glial cells) • “Nerve glue” • Includes many types of cells that support, insulate, & protect the delicate neurons • Each type has specific functions

  9. Nervous Tissue: Neurons • Neurons = Nerve cells • Cells specialized to transmit messages • Nerve impulses • Major regions of Neurons • Cell body – Contains the nucleus and is the metabolic center of the cell • Processes – Fibers that extend from the cell body (dendrites and axons)

  10. Neuron Anatomy • Cell body • Nucleus • Metabolic Center

  11. Neuron Anatomy • Extensions outside the cell body • Dendrites – Conduct impulses toward the cell body • Axons – Conduct impulses Away from the cell body

  12. Axons and Nerve Impulses • Axons end in axonal terminals • Axon terminals contain vesicles that contain neurotransmitters • Axon terminals are separated from the next neuron by a gap • Synaptic cleft – just the space between adjacent neurons • Synapse – junction between neurons; including the membranes of both neurons & the space between them

  13. Nerve Fiber Coverings • Myelin • Covers nerve fibers • Whitish, fatty material • Waxy appearance • Protects & insulates the fibers • Increases the transmission rate of nerve impulses • Schwann cells – produce myelin sheaths in jelly-roll like fashion • Nodes of Ranvier – gaps in the myelin sheath along the axon

  14. Application of Neurons • Multiple sclerosis (MS) • Chronic, potentially debilitating disease that affects the central nervous system, which is made up of the brain and spinal cord. • Myelin sheath is destroyed- It hardens to a tissue called the scleroses • Transmitted nerve impulses are short-circuited • Affected person loses control of his/her muscles and becomes increasingly more disabled • Autoimmune disease • Protein component of the sheath is attacked • No cure • Interferon injections • Hormone like substance released by some immune cells- provides relief • website

  15. Multiple Sclerosis

  16. Neuron Cell Body Location • Most neurons are found in the central nervous system • White matter- dense collections of myelinated fibers • Gray matter – unmyelinated fibers & cell bodies • Nuclei – clusters of cell bodies within the white matter of the central nervous system • Ganglia – collections of cell bodies outside the central nervous system (PNS)

  17. Functional Classification of Neurons • Sensory (afferent) neurons • Carry impulses from the sensory receptors to the CNS • Cutaneous sense organs (Vision, hearing, equilibrium, taste & smell) • Proprioceptors – detect stretch or tension in skeletal muscles, tendons and joints • Pain receptors

  18. Functional Classification of Neurons Motor (efferent) neurons • Carry impulses from the central nervous system to the viscera and/or muscles and glands Interneurons (association neurons) • Connect sensory and motor neurons in neural pathways

  19. Neuron Classification

More Related