Differentiate the components of each division of the central nervous system.

• • Its primary function is to prepare the body for immediate action.
• Parasympathetic Nervous System:
  • This is the "rest-and-digest" system. It predominates during relaxation and normal bodily functions.
  • Physiological effects include:
    • Decreased heart rate and blood pressure.
    • Constricted pupils.
    • Bronchoconstriction (narrowing of airways).
    • Increased digestive activity.
    • Stimulation of salivation.
  • Its primary function is to conserve energy and maintain homeostasis.
  • The neurotransmitter most associated with the parasympathetic nervous system is acetylcholine.

In essence, the sympathetic nervous system mobilizes the body for action, while the parasympathetic nervous system promotes relaxation and restoration.

2. Differentiate the components of each division of the peripheral nervous system.

The peripheral nervous system (PNS) connects the central nervous system (CNS) to the rest of the body. ¹ It's divided into two main divisions:  

• Somatic Nervous System:
  • This division controls voluntary movements of skeletal muscles.
  • It consists of:
    • Sensory neurons (afferent) that transmit information from sensory receptors (e.g., skin, muscles) to the CNS.
    • Motor neurons (efferent) that transmit signals from the CNS to skeletal muscles.
  • It is responsible for conscious control of movement and sensory perception.
• Autonomic Nervous System:
  • This division controls involuntary functions of smooth muscle, cardiac muscle, and glands.
  • It's further divided into:
    • Sympathetic Nervous System: (as described above)
    • Parasympathetic Nervous System: (as described above)
    • Enteric Nervous System: This is sometimes considered a third division of the autonomic, and is responsible for governing the functions of the gastrointestinal system.
  • The autonomic nervous system regulates essential bodily functions like heart rate, digestion, respiration, and glandular secretions.

The key difference lies in the type of control: the somatic nervous system is for voluntary movements, while the autonomic nervous system is for involuntary functions

Differentiate the parasympathetic and sympathetic nervous systems.

The autonomic nervous system, a division of the peripheral nervous system, controls involuntary bodily functions. It's further divided into the parasympathetic and sympathetic nervous systems, which often have opposing effects.

• Sympathetic Nervous System:
  • This is the "fight-or-flight" system. It activates during stress or perceived danger.
  • Physiological effects include:
    • Increased heart rate and blood pressure.
    • Dilated pupils.
    • Bronchodilation (widening of airways).
    • Decreased digestive activity.