Nervous System Overview

  • Overview of the Nervous System

    • Central Nervous System (CNS): Brain and spinal cord
    • Peripheral Nervous System (PNS): Nerves beyond the brain and spinal cord

  • Functional Organization

    • CNS processes sensory (afferent) inputs and generates motor (efferent) outputs
    • Functions in integration and reflexes

  • Neurons

    • Main cell type in the nervous system that conducts electrical signals
    • Differences between neurons (individual cells) and nerves (bundles of neurons)

  • Supporting Cells

    • Oligodendrocytes (CNS) and Schwann cells (PNS): Produce myelin sheaths
    • Astrocytes: Support and protect neurons; important for integrity of the CNS
    • Microglial cells: Immune function in the CNS
    • Ependymal cells: Produce cerebrospinal fluid (CSF)

  • Brain Structure

    • Divided into four main parts: Cerebrum, Diencephalon, Cerebellum, Brain Stem
    • Cerebrum: Largest part; processes sensory information, voluntary movement
    • Diencephalon: Thalamus (relay station) and Hypothalamus (regulates autonomic functions)
    • Cerebellum: Coordinates fine motor movements
    • Brain Stem: Controls basic life functions (breathing, heart rate)

  • Spinal Cord and Nerves

    • Divided into cervical, thoracic, lumbar, sacral, and coccygeal regions
    • Spinal Nerves: 32 pairs, each connected to specific areas of the body
    • Dorsal (afferrent sensory signals) and Ventral (efferent motor signals) pathways

  • Reflexes

    • Involuntary responses processed at spinal cord level with fast reaction times
    • Involves sensory input, integration, and motor output in a reflex arc

  • Functional Divisions of Peripheral Nervous System

    • Afferent (sensory) division: Carries signals into CNS
    • Efferent (motor) division: Divided into Somatic (voluntary muscle) and Autonomic (involuntary organs)

  • Key Terminology

    • Afferent: Sensory signals entering the CNS
    • Efferent: Motor signals exiting the CNS
    • Cervical, Thoracic, Lumbar, Sacral, Coccygeal: Classifications of spinal nerves
    • Somatic system: Skeletal muscle control
    • Autonomic system: Organ function control

  • Neuron Types and Pathways

    • Neurons are categorized based on location and function (sensory, motor, interneurons)
    • Sensory neurons connect to CNS from sensory receptors, motor neurons connect from CNS to muscles

  • Summary of Brain Functions

    • Cerebrum: Thought, emotion, sensory perception
    • Diencephalon: Sensory relay and hormonal control
    • Cerebellum: Motor coordination and timing
    • Brain Stem: Vital functions control and reflexes

  • Web Resources: Recommendations for further study and review notes for upcoming tests.

  • Additional materials and questions to prepare for the upcoming learning assessments.