Study Question Seventeen

• Q17. Distinguish between the sympathetic and parasympathetic nervous systems on the basis of their organization, origin, general innervation, and function.
• The sympathetic and parasympathetic nervous systems are two branches of the autonomic nervous system, each with distinct characteristics.
• Organization

  • Sympathetic Nervous System (SNS): Generally organized into a network of ganglia located close to the spinal cord, known as the sympathetic chain (or trunk). It has a more diffuse organization, allowing for widespread effects on target organs.
  • Parasympathetic Nervous System (PNS): Organized with ganglia located closer to or within the walls of target organs. This allows for more localized control over specific organs.
• Organization

  • Sympathetic Nervous System (SNS): Generally organized into a network of ganglia located close to the spinal cord, known as the sympathetic chain (or trunk). It has a more diffuse organization, allowing for widespread effects on target organs.
  • Parasympathetic Nervous System (PNS): Organized with ganglia located closer to or within the walls of target organs. This allows for more localized control over specific organs.
• Origin

  • Sympathetic Nervous System: Originates from T1 - L2. The preganglionic neurons are short, and they synapse in the sympathetic ganglia.
  • Parasympathetic Nervous System: Originates from cranial nerves III, VII, IX, and X, and sacral spinal nerves S2-S4. The preganglionic neurons are long, extending to ganglia near or within target organs.
• Origin

  • Sympathetic Nervous System: Originates from T1 - L2. The preganglionic neurons are short, and they synapse in the sympathetic ganglia.
  • Parasympathetic Nervous System: Originates from cranial nerves III, VII, IX, and X, and sacral spinal nerves S2-S4. The preganglionic neurons are long, extending to ganglia near or within target organs.
• General Innervation

  • Sympathetic Nervous System: Innervates a wide range of organs, including the heart, lungs, digestive system, and sweat glands. It also affects blood vessels throughout the body.
  • Parasympathetic Nervous System: Primarily innervates organs in the head, neck, thorax, and abdomen, such as the heart, lungs, and digestive organs. Its influence is more focused on specific organs.
• General Innervation

  • Sympathetic Nervous System: Innervates a wide range of organs, including the heart, lungs, digestive system, and sweat glands. It also affects blood vessels throughout the body.
  • Parasympathetic Nervous System: Primarily innervates organs in the head, neck, thorax, and abdomen, such as the heart, lungs, and digestive organs. Its influence is more focused on specific organs.
• Function

  • Sympathetic Nervous System: "Fight or flight". Increasing heart rate, dilating bronchi, inhibiting digestion, and mobilizing energy reserves. It enhances alertness and physical readiness.
  • Parasympathetic Nervous System: "Rest and digest". Decreasing heart rate, constricting bronchi, stimulating digestion, and conserving energy. It is responsible for maintaining homeostasis and promoting recovery.
• Function

  • Sympathetic Nervous System: "Fight or flight". Increasing heart rate, dilating bronchi, inhibiting digestion, and mobilizing energy reserves. It enhances alertness and physical readiness.
  • Parasympathetic Nervous System: "Rest and digest". Decreasing heart rate, constricting bronchi, stimulating digestion, and conserving energy. It is responsible for maintaining homeostasis and promoting recovery.
• Function

  • Sympathetic Nervous System: "Fight or flight". Increasing heart rate, dilating bronchi, inhibiting digestion, and mobilizing energy reserves. It enhances alertness and physical readiness.
  • Parasympathetic Nervous System: "Rest and digest". Decreasing heart rate, constricting bronchi, stimulating digestion, and conserving energy. It is responsible for maintaining homeostasis and promoting recovery.
• In essence, the sympathetic nervous system is geared towards immediate, widespread responses to stress, while the parasympathetic nervous system supports long-term maintenance and recovery processes, highlighting their complementary roles in regulating bodily functions.