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Chapter 1-8 Neurophysiology: Nervous System, Neurons, Glia, Resting Membrane Potential, and Action Potentials

Nerve Cells and Electrical Signaling

Overview of the Nervous System

  • The nervous system is crucial for communication within the body, underpinning all actions, thoughts, and emotions.

  • This communication occurs rapidly, within milliseconds.

  • Two primary types of rapid communication exist:

    • Electrical signals.

    • Chemical signals.

Divisions of the Nervous System (Anatomy Background)

  • Central Nervous System (CNS):

    • Consists of the brain and spinal cord.

  • Peripheral Nervous System (PNS):

    • Comprises everything outside the CNS, primarily nerves.

    • Functions to relay information from the environment (internal or external) to the CNS and transmit information from the CNS to effector cells and organs.

Functions of the Nervous System

  • Sensory Input:

    • The PNS gathers stimuli from the environment and transmits this information towards the CNS.

  • Integration:

    • An integration center (located in the CNS) processes and interprets the sensory input, leading to a decision about the body's response.

  • Motor Output:

    • A signal is sent from the CNS to an effector organ (e.g., muscle or gland) to produce a response to the stimuli.

Organization of the Peripheral Nervous System

  • The PNS is divided into two major portions:

    • Sensory Division (Afferent Division):

      • Carries information at the CNS (towards the CNS). An easy mnemonic is that