Cranial Nerves

Question 1

When you learn about _____, you’re really learning about how the external world enters your mind.

Answer 1

cranial nerves

Question 2

What are cranial nerves?

Answer 2

• Nerves emerging directly from brain
• Part of the PNS (except CN I (olfactory) and II (optic))
• Largely serve motor and sensory systems of head & neck
• –> Some (CN X (vagus) and XI (spinal accessory) reach further into periphery.

Question 3

CN 1 (I)

Answer 3

• Olfactory

- Sensory

Question 4

CN 2 (II)

Answer 4

• Optic

- Sensory

Question 5

CN 3 (III)

Answer 5

• Oculomotor

- Motor

Question 6

CN 4 (IV)

Answer 6

• Trochlear

- Motor

Question 7

CN 5 (V)

Answer 7

• Trigeminal
• Both
• Receives sensory info about:
  
  • touch on face and jaw position
  • pain and temperature on face
• Innervates muscles for chewing (motor)

Question 8

CN 6 (VI)

Answer 8

• Abducens

- Motor

Question 9

CN 7 (VII)

Answer 9

• Facial
• Both
• Closes the eyelids (motor)
• Controls facial muscles for expressions (motor)
• Involved in taste (sensory)

Question 10

CN 8 (VIII)

Answer 10

• Acoustic (Vestibulocochlear)
• Sensory
• Sensory information from vestibular system (semicircular canals of the inner ear)
  
  • Fluid-filled canals that aid in balance

Question 11

CN 9 (IX)

Answer 11

• Glossopharyngeal
• Both
• Innervates the posterior 1/3 of the tongue
• Involved in gag reflex and swallowing (motor) and taste (sensory)

Question 12

CN 10 (X)

Answer 12

• Vagus
• Both
• Part of the autonomic nv. system (Parasympathetic)
  
  • enhances energy storage
  • decreases cardiac output and blood press.
  • increases salivation
  • bladder contraction
  • involved in gag reflex
  • “Rest & digest”

Question 13

CN 11 (XI)

Answer 13

• Spinal Accessory
• Motor
• Innervates pharynx and larynx (vocal cords)
• Controls muscles of neck (motor)

Question 14

CN 12 (XII)

Answer 14

• Hypoglossal
• Motor
• Responsible for some tongue movements (motor)