Nervous System

• Nervous System


  Controls mental and physical activities, whether they are voluntary or involuntary
• Nervous System


  • Sends electrical signals around the body, allowing the body to react to its surroundings quickly
• Transmission of signals

  From one neuron to the next and within the neuron itself
• Without the nervous system, we would not be able to function normally
• Basic functions of the Nervous System

  • Sensory
  • Motor
  • Integrative or mixed
• Sensory neurons


  Carry impulses from sensory organs to the brain (Afferent Neurons)
• Motor neurons


  Carry impulses from the brain to certain muscles and glands, and signals for them to carry out actions (Efferent neurons)
• Relay neurons or Interneurons


  Carry impulses between sensory and motor neurons
• Parts of the Nervous System

  • Central Nervous System (CNS)
  • Peripheral Nervous System (PNS)
• Central Nervous System (CNS)


  • Serves as the processing area of the nervous system
  • Composed of the brain and spinal cord
  • The brain processes and interprets the signals transmitted to it
  • The spinal cord connects the brain to the rest of the body
• Parts of the Brain


  • Cerebrum
  • Cerebellum
  • Brain stem

  
• Cerebrum


  • The main part of the brain, divided into 4 lobes, controlling conscious functions
• Lobes of the Cerebrum

  • Frontal lobe
  • Parietal lobe
  • Temporal lobe
  • Occipital lobe
• Cerebellum


  • Controls body movement or body coordination of skeletal contractions, for posture and balance
• Parts of the Brain Stem


  • Medulla oblongata
  • Midbrain
  • Pons
• Peripheral Nervous System (PNS)


  • All the neurons and sensory organs in the body not included in the central nervous system
  • Connected to the CNS by nerves
  • Divided into the sensory (sends information to the central nervous system) and motor (sends Information to muscle and glands) systems
• Divisions of the PNS

  • Somatic Nervous System
  • Autonomic Nervous System
• Autonomic Nervous System (ANS)


  Controls all involuntary actions, functions independently and is not consciously controlled
• Divisions of the ANS


  • Sympathetic Division
  • Parasympathetic Division
• Sympathetic Division


  • Puts the body in "fight or flight mode", activated during physical or emotional stress, stimulated by fear, embarrassment or anger
• Parasympathetic Division


  • Functions whenever the body is at rest and recovery, controls non-emergency bodily functions such as digestion
• Effects of Sympathetic and Parasympathetic Divisions

  • Heart
  • Arteries
  • Eyes
  • Sweat Glands
  • Salivary Glands
• Somatic Nervous System (SNS)


  Controls all voluntary and conscious actions, also controls reflexes
• Components of the SNS

  • Motor Nerves
  • Spinal Nerves
  • Cranial Nerves