Nervous System]

• The Nervous System is the body's most complex system, consisting of cells, tissues, and organs that regulate the body's responses to internal and external stimuli
• Together with the endocrine system, the brain controls the organism
• The Nervous System is divided into two major divisions: the central (brain and spinal cord) and the peripheral (nerves of the spinal cord and cranium)
• The Central Nervous System (CNS) serves as the main processing center, consisting of the brain and spinal cord
• The Brain is the body's control center, using one fifth of the oxygen inhaled and is one of the most protected parts of the body
• Cerebrum is the largest portion of the brain responsible for intelligence and reasoning
• Limbic System controls posture, balance, coordination, visual and auditory reflexes
• Brainstem connects the brain to the spinal cord and controls automatic functions like breathing, digestion, heart rate, and blood pressure
• The Spinal Cord channels signals between the brain and the body and performs reflex actions
• The Peripheral Nervous System (PNS) provides information to the central nervous system and coordinates movements
• The Sensory division informs the central nervous system about external and internal changes detected by the senses
• The Motor division sends instructions for conscious movement of muscles and is associated with voluntary control of body movements
• The Autonomic division automatically controls the functioning of internal organs, associated with involuntary control of body movements
• Sympathetic division prepares the body for action in dynamic roles or stress, known as "fight or flight"
• Parasympathetic division maintains body functions and restores the body to a normal or relaxed mode, known as "rest and digest"
• Area affected by Parasympathetic (rest and digest) and Sympathetic (fight or flight) responses:

  • Eye: Constricts pupils (Parasympathetic) / Dilates pupils (Sympathetic)
  • Salivary gland: Stimulates saliva production (Parasympathetic) / Inhibits (Sympathetic)
  • Lungs (bronchioles): Constricts (Parasympathetic) / Dilates (Sympathetic)
  • Heart rate: Decrease (Parasympathetic) / Increase (Sympathetic)
  • Gastrointestinal tract: Stimulates digestion (Parasympathetic) / Inhibits (Sympathetic)
  • Urination: Stimulate (Parasympathetic) / Inhibit (Sympathetic)
• The Nervous System is the body's most complex system, consisting of cells, tissues, and organs that regulate the body's responses to internal and external stimuli
• Together with the endocrine system, the brain controls the organism
• The Nervous System is divided into two major divisions: the central (brain and spinal cord) and the peripheral (nerves of the spinal cord and cranium)
• The Central Nervous System (CNS) serves as the main processing center, consisting of the brain and spinal cord
• The Brain is the body's control center, using one fifth of the oxygen inhaled and responsible for rapid and intellectual activities like memory, emotions, and will
• Cerebrum is the largest portion of the brain, responsible for intelligence and reasoning
• Limbic System controls posture, balance, coordination, visual and auditory reflexes
• Brainstem connects the brain to the spinal cord and controls automatic functions like breathing, digestion, heart rate, and blood pressure
• The Spinal Cord channels signals between the brain and the rest of the body and performs reflex actions
• The Peripheral Nervous System (PNS) provides information to the central nervous system and coordinates movements, connecting the CNS to organs and limbs
• The Sensory Division informs the CNS about external and internal changes detected by the senses
• The Motor Division sends instructions for conscious movement of muscles and is associated with voluntary control of body movements
• The Autonomic Division automatically controls the functioning of internal organs, associated with involuntary control of body movements
• Sympathetic division prepares the body for action in dynamic roles or stress, while the Parasympathetic division maintains body functions and restores the body to a normal or relaxed mode
• Area affected by Parasympathetic (rest and digest) and Sympathetic (fight or flight) responses:

  • Eye: Constricts pupils (Parasympathetic) / Dilates pupils (Sympathetic)
  • Salivary gland: Stimulates saliva production (Parasympathetic) / Inhibits (Sympathetic)
  • Lungs (bronchioles): Constricts (Parasympathetic) / Dilates (Sympathetic)
  • Heart rate: Decrease (Parasympathetic) / Increase (Sympathetic)
  • Gastrointestinal tract: Stimulates digestion (Parasympathetic) / Inhibits (Sympathetic)
  • Urination: Stimulate (Parasympathetic) / Inhibit (Sympathetic)