Topic 7: Nervous System Part 2: Peripheral Nervous System

• How many pairs of cranial nerves are there?

  12 pairs
• What are the two types of nerves in the peripheral nervous system?

  Cranial nerves and spinal nerves
• How many pairs of spinal nerves are there?

  31 pairs
• What are the two main divisions of the peripheral nervous system?

  • Somatic Nervous System (voluntary)
  • Autonomic Nervous System (involuntary)
• What does the somatic nervous system do?

  Transmits signals from receptors to CNS
• What is the role of the autonomic nervous system?

  Regulates involuntary responses
• What are the two divisions of the autonomic nervous system?

  Sympathetic and parasympathetic
• What is the function of the sympathetic nervous system?

  Prepares the body for stress responses
• What does the parasympathetic nervous system do?

  Promotes rest and digestion
• What is the primary neurotransmitter released by sympathetic neurons?

  Norepinephrine
• What are the four conditions needed for a sensation to occur?

  A stimulus, sensory receptor, nerve impulses, brain integration
• What type of receptors are Meissner's corpuscles?

  Light touch receptors
• What do Pacinian corpuscles detect?

  Heavy pressure and vibration
• How many receptors for smell does the nose contain?

  10–100 million
• What are the five primary tastes in gustation?

  Sour, sweet, bitter, salty, umami
• What is the role of the external ear?

  Collects sound waves and channels them
• How does the nervous system contribute to homeostasis?

  • Monitors internal and external conditions
  • Sends impulses to restore norms
  • Regulates muscle contractions and responses
• What happens to the brain as a person ages?

  Decline in brain mass and function
• What is a stroke?

  Blood supply to the brain is cut off
• What is Alzheimer Disease associated with?

  Ongoing decline of brain functioning
• What is the function of the vagus nerve?

  Carries 75% of parasympathetic fibers
• What is the role of the hypothalamus in the autonomic nervous system?

  Regulates the autonomic nervous system
• How do the sympathetic and parasympathetic divisions of the autonomic nervous system interact?

  They provide dual innervation to most organs
• What is the primary function of skin receptors?

  Register changes in temperature and pressure
• What is the primary function of the olfactory epithelium?

  Contains receptors for the sense of smell
• What is the function of the gustatory pathway?

  Conducts taste impulses to the brain
• What are the three main regions of the ear?

  External, middle, internal ear
• What is the role of the middle ear?

  Conveys sound vibrations to the oval window
• What is the primary role of the internal ear?

  Houses receptors for hearing and equilibrium
• What are the effects of aging on the nervous system?

  • Rapid brain growth in early life
  • Decline in brain mass with age
  • Fewer synaptic contacts
  • Decrease in brain function
• What are common disorders that affect the nervous system?

  • Stroke
  • Cancer
  • Alzheimer Disease