2: The Peripheral Nervous System

Question 1

CN: 1. Olfactory

Answer 1

• Sensory

- Smell

Question 2

CN: 2. Optic

Answer 2

• Sensory

- Vision

Question 3

CN: 3. Oculomotor

Answer 3

• Motor

- Eye movements, pupil constriction, raising eyelids

Question 4

CN: 4. Trochlear

Answer 4

• Motor

- Eye movements (superior oblique muscle)

Question 5

CN: 5. Trigeminal

Answer 5

• Sensory and motor

- Sensation to head and face, including gums and teeth, movement of muscles of mastication

Question 6

CN: 6. Abducens

Answer 6

• Motor

- Eye movements (lateral rectus muscle)`

Question 7

CN: 7. Facial

Answer 7

• Sensory and motor

- Taste from anterior 2/3 of the tongue, movement of muscles of facial expression

Question 8

CN: 8. Vestibulocochlear

Answer 8

• Sensory

- Hearing and balance

Question 9

CN: 9. Glossopharyngeal

Answer 9

• Sensory and motor

- Taste from posterior 1/3 of the tongue, swallowing, salivary secretion

Question 10

CN: 10. Vagus

Answer 10

• Sensory and motor

- S&M supply to most organs

Question 11

CN: 11. Accessory

Answer 11

• Motor

- Movement of neck muscles, voluntary swallowing and vocal cords

Question 12

CN: 12. Hypoglossal

Answer 12

• Motor

- Tongue movements

Question 13

Smell (Olfaction)

Answer 13

• 5000 different scents
• Our sense of smell deteriorates over time
• Need to smell for food, mates, friends, foe, etc.
• Chemical sense

Question 14

Vision

Answer 14

• Extremely high acuity colour vision

- Binocular vision gives us depth perception

Question 15

Taste

Answer 15

• Chemical sense
• 5 tastes:
  > Bitter - potentially poisonous
  > Salty - important electrolyte content
  > Sweet - energy content
  > Umami (savoury) - amino acid content
  > Sour - potentially poisonous

Question 16

Hearing and Balance

Answer 16

• Cochlear: hearing
• Semi-circular canals: balance
• Auditory nerve: sensitive information up to the brain regarding balance and hearing
• Eustachian tube: connects the back of the throat to the ear

Question 17

Spinal Nerves: Dermatomes

Answer 17

• Cervical nerves: upper limb, neck, and back of head
• Thoracic nerves: parts of the torso, posterior aspects of the arm
• Lumbar nerves: lower limbs (anterior mainly), hips, and buttocks

Question 18

Spinal Nerves: Myotomes

Answer 18

The skeletal muscles supplied by the motor nerve fibres in each spinal nerve.

Question 19

Proprioception

Answer 19

• Our sense of body position
• Provided by two types of receptors: muscle spindles and golgi tendon organs
• Allows us to monitor movements and position without needing to look at ourselves