Chapter 13

  1. Neurons

    • Specialized cells sending and receiving electrical impulses.

    • Critical for processing and transmitting information throughout the body.

  2. Glial Cells

    • Support neuron functions: microglia, oligodendrocytes, Schwann cells, astrocytes.

    • Provide structural support, nutritional assistance, and waste removal.

  3. Nervous System Overview

    • Central Nervous System (CNS): Brain and spinal cord, processing information and controlling responses.

    • Peripheral Nervous System (PNS): Links CNS to limbs and organs, divided into somatic (voluntary) and autonomic (involuntary) systems.

  4. Types of Neurons

    • Sensory Neurons: Detect environmental stimuli, convert signals into neural impulses to the CNS.

    • Motor Neurons: Relay signals from CNS to muscles and glands, vital for movement and hormone secretion.

    • Interneurons: Connect sensory and motor neurons, processing signals and performing complex tasks.

  5. Neuron Structure

    • Cell Body: Contains nucleus and organelles for metabolic functions and signal integration.

    • Dendrites: Receive signals, increasing surface area for input.

    • Axon: Conducts signals away from the cell body, ending in synaptic boutons.

    • Myelin Sheath: Insulates axons to speed up signal transmission.

  6. Action Potentials and Membrane Potential

    • Resting Membrane Potential: Typically -60 to -75 mV.

    • Action Potential: Rapid changes in membrane potential through depolarization and repolarization phases.

  7. Ion Concentrations & Channels

    • Potassium (K+): More concentrated inside, contributes to resting potential.

    • Sodium (Na+): More outside, movement causes depolarization.

    • Ion Channels: Voltage-gated, ligand-gated, and leak channels regulate ion flow.

  8. Signal Propagation

    • Continuous Conduction: Gradual depolarization in non-myelinated axons.

    • Saltatory Conduction: Jumping action potentials between nodes of Ranvier in myelinated axons.

  9. Synaptic Transmission

    • Electrical Synapses: Direct connections for rapid communication.

    • Chemical Synapses: Use neurotransmitters for slower, regulated signaling.

  10. Neurotransmitters

  • Types: Amino acids, monoamines, neuropeptides.

  • Function: Can be excitatory or inhibitory, influencing target neuron behavior.

  • Receptors: Ligand-gated and metabotropic receptors mediate responses.

  1. Signal Integration

  • Postsynaptic Potentials (PSPs): Lead to potential action potentials.

  • Temporal Summation: Cumulative effects from rapid signals.

  • Spatial Summation: Multiple signals combine to initiate action potential based on total input.