Cranial and Spinal Nerves

Question 1

How many pairs of Cranial Nerve are there?

Answer 1

12

Question 2

How many pairs of Spinal Nerve are there?

Answer 2

31

Question 3

List the 12 Cranial Nerves in order.

Answer 3

• Olfactory (I) – Smell
• Optic (II) – Vision
• Oculomotor (III) – Eye movement
• Trochlear (IV) – Eye movement
• Trigeminal (V) – Facial sensation & chewing
• Abducens (VI) – Eye movement
• Facial (VII) – Facial expressions & taste
• Vestibulocochlear (VIII) – Hearing & balance
• Glossopharyngeal (IX) – Taste & swallowing
• Vagus (X) – Controls heart, lungs, digestion
• Accessory (XI) – Neck & shoulder movement
• Hypoglossal (XII) – Tongue movement

Question 4

List the 5 Groups of Spinal Nerves.

Answer 4

• Cervical (C1-C8): Neck, shoulders, arms, hands
• Thoracic (T1-T12): Chest, upper abdomen
• Lumbar (L1-L5): Lower back, hips, legs
• Sacral (S1-S5): Pelvis, lower limbs
• Coccygeal (Co1): Tailbone sensation

Question 5

Which cranial nerve is responsible for detecting smell?

Answer 5

Olfactory Nerve (CN I)

Question 6

A patient comes to the clinic complaining that they can’t smell their food or perfume. Which cranial nerve might be affected?

Answer 6

Olfactory Nerve (CN I)

Question 7

Which cranial nerve transmits visual information to the brain?

Answer 7

Optic Nerve (CN II)

Question 8

A person has difficulty reading signs from a distance and reports blurry vision. Which cranial nerve is likely involved?

Answer 8

Optic Nerve (CN II)

Question 9

Which cranial nerve controls most eye movements?

Answer 9

Oculomotor Nerve (CN III)

Question 10

A patient has trouble opening their eyes and their pupils remain dilated. Which cranial nerve might be damaged?

Answer 10

Oculomotor Nerve (CN III)

Question 11

Which cranial nerve controls the superior oblique muscle of the eye?

*eye downward and inward

Answer 11

Trochlear Nerve (CN IV)

Question 12

A person is unable to look downward while reading a book or walking downstairs. Which cranial nerve is affected?

Answer 12

Trochlear Nerve (CN IV)

Question 13

Which cranial nerve is responsible for eyes, facial, mouth sensation and chewing?

Answer 13

Trigeminal Nerve (CN V)

Question 14

A patient complains of numbness in their face and has difficulty chewing. Which cranial nerve is most likely involved?

Answer 14

Trigeminal Nerve (CN V)

Question 15

Which cranial nerve controls lateral eye movement?

sideways and inward

Answer 15

Abducens Nerve (CN VI)

Question 16

A patient’s eye stays in the middle when they try to look sideways. Which cranial nerve might be damaged?

Answer 16

Abducens Nerve (CN VI)

Question 17

Which cranial nerve controls facial expressions and taste?

Answer 17

Facial Nerve (CN VII)

Question 18

A patient has trouble smiling, raising their eyebrows, and tasting sweet foods on the front of their tongue. Which cranial nerve is affected?

Answer 18

Facial Nerve (CN VII)

Question 19

Which cranial nerve is responsible for hearing and balance?

Answer 19

Vestibulocochlear Nerve (CN VIII)

Question 20

A person reports feeling dizzy and has trouble maintaining balance. They also have difficulty hearing. Which cranial nerve might be affected?

Answer 20

Vestibulocochlear Nerve (CN VIII)

Question 21

Which cranial nerve controls taste, swallowing, and blood pressure regulation?

Answer 21

Glossopharyngeal Nerve (CN IX)

Question 22

A patient has difficulty swallowing and cannot taste bitter foods on the back of their tongue. Which cranial nerve is likely involved?

Answer 22

Glossopharyngeal Nerve (CN IX)

Question 23

Which cranial nerve regulates autonomic functions such as digestion, heart rate, and respiratory processes as well as saliva production?

Answer 23

Vagus Nerve (CN X)

Question 24

A patient experiences difficulty breathing and has an unusually slow heart rate. Which cranial nerve might be affected?

Answer 24

Vagus Nerve (CN X)

Question 25

Which cranial nerve controls shoulder and neck movements?

Answer 25

Accessory Nerve (CN XI)

Question 26

A patient cannot shrug their shoulders or turn their head against resistance. Which cranial nerve is damaged?

Answer 26

Accessory Nerve (CN XI)

Question 27

Which cranial nerve controls tongue movement which plays a role in speaking, eating and swallowing?

Answer 27

Hypoglossal Nerve (CN XII)

Question 28

A patient has difficulty moving their tongue and cannot pronounce words properly. Which cranial nerve is affected?

Answer 28

Hypoglossal Nerve (CN XII)

Question 29

A 65-year-old patient presents with difficulty swallowing, hoarseness in their voice, and an erratic heart rate. A physical exam shows a loss of the gag reflex. Which cranial nerve is most likely affected? | *Explain your answer.*

Answer 29

Vagus Nerve (CN X) ## Footnote * The vagus nerve controls autonomic functions like heart rate and digestion, and it also plays a role in voice control (laryngeal muscles) and swallowing. * The loss of the gag reflex and the hoarseness suggest vagus nerve dysfunction, as it innervates the muscles of the larynx and pharynx.

Question 30

A patient has a drooping eyelid (ptosis), a dilated pupil that does not constrict in response to light, and difficulty moving their eye upward, downward, and inward. Which cranial nerve is affected? | *Explain your answer.*

Answer 30

Oculomotor Nerve (CN III) ## Footnote * CN III controls most extraocular muscles, including those responsible for moving the eye up, down, and inward. * It also controls the levator palpebrae superioris, which lifts the eyelid. * It carries parasympathetic fibers that constrict the pupil, so damage results in pupil dilation.

Question 31

A patient presents with sudden hearing loss in one ear, difficulty maintaining balance, and vertigo. There are no signs of facial muscle weakness. Which cranial nerve is most likely affected? | *Explain your answer.*

Answer 31

Vestibulocochlear Nerve (CN VIII) ## Footnote * CN VIII is responsible for hearing (cochlear branch) and balance (vestibular branch). * Damage results in sensorineural hearing loss and vertigo due to impaired vestibular function.

Question 32

A 50-year-old patient complains of frequent choking while eating, a loss of taste on the posterior third of the tongue, and difficulty elevating the pharynx during swallowing. Which cranial nerve is most likely damaged? | *Explain your answer.*

Answer 32

Glossopharyngeal Nerve (CN IX)

Question 33

A patient reports that they cannot turn their head to the left against resistance and have difficulty shrugging their right shoulder. Upon examination, their right sternocleidomastoid and trapezius muscles appear weak. Which cranial nerve is affected? | *Explain your answer.*

Answer 33

Accessory nerve (CN XI) ## Footnote * CN XI innervates the sternocleidomastoid and trapezius muscles. * Damage to the right CN XI results in weakness of the right trapezius (shoulder shrugging) and the left-turning function of the right sternocleidomastoid.

Question 34

A patient has slurred speech and difficulty moving their tongue from side to side. When they stick out their tongue, it deviates to the right. Which cranial nerve is affected? | *Explain your answer.*

Answer 34

Hypoglossal Nerve (CN XII) ## Footnote * CN XII controls tongue movement. * When damaged on one side, the tongue deviates toward the weaker side because the strong side overpowers it. * Slurred speech (dysarthria) can result from poor tongue control.

Question 35

Cameron presents to the clinic complaining of a **spinning sensation** that started suddenly after getting out of bed this morning. She reports **hearing a ringing sound in her left ear** and feels like her **left ear is full**. She has difficulty **maintaining balance** while walking, and the sensation seems to worsen when she moves her head. Which cranial nerve is likely affected? | *Explain your answer.*

Answer 35

Vestibulocochlear Nerve (CN VIII) ## Footnote The Vestibulocochlear Nerve (Cranial Nerve VIII) is responsible for: * Hearing (via the cochlear branch) * Balance and spatial orientation (via the vestibular branch)

Question 36

Chase has **slurred speech, difficulty chewing,** and a **tongue that deviates to the left when protruded**. Which cranial nerve is most likely responsible for these symptoms? | *Explain your answer.*

Answer 36

Hypoglossal Nerve (CN XII) ## Footnote The Hypoglossal Nerve (Cranial Nerve XII) controls tongue movement and is responsible for: * Coordinating speech (articulation) * Aiding in chewing and swallowing * Controlling tongue protrusion and movement

Question 37

House is always complaining of **numbness around his face** and **difficulty chewing**. He also has a noticeable **weakness in the muscles of his right cheek**. Which cranial nerve is most likely involved in his condition? | *Explain your answer.*

Answer 37

Trigeminal Nerve (CN V) ## Footnote The Trigeminal Nerve (Cranial Nerve V) is responsible for: * Facial sensation (touch, pain, temperature) * Motor control of the muscles of mastication (chewing)

Question 38

Cuddy's grandma, a 58-year-old woman presents with a sudden **loss of vision in the right eye**. Upon examination, the Doctor notice that the **right pupil is dilated and unresponsive to light.** Which cranial nerve might be affected? | *Explain your answer.*

Answer 38

Oculomotor Nerve (CN III) ## Footnote The Oculomotor Nerve (Cranial Nerve III) controls: * Pupillary constriction (via the parasympathetic fibers). * Eye movement (except for lateral movement and downward-outward movement). * Eyelid elevation (levator palpebrae superioris muscle).

Question 39

Foreman has **difficulty swallowing**, a sensation of a **lump in his throat**, and a **dry mouth**. He also experiences a **loss of taste** on the **posterior third of his tongue**. Which cranial nerve is most likely affected? | *Explain your answer.*

Answer 39

Glossopharyngeal Nerve (CN IX) ## Footnote The Glossopharyngeal Nerve (Cranial Nerve IX) is responsible for: * Swallowing (controls part of the pharyngeal muscles) * Taste & sensation from the posterior third of the tongue * Salivation (stimulates the parotid gland for saliva production)

Question 40

Dr. Wilson takes a sip of hot coffee and immediately pulls away because **it burns his tongue**. Which cranial nerve is responsible for detecting the heat and pain from the coffee? | *Explain your answer.*

Answer 40

Trigeminal Nerve (CN V) ## Footnote The Trigeminal Nerve (Cranial Nerve V) is responsible for detecting heat, pain, and touch sensations from the face, mouth, and tongue. Specifically: * The Mandibular branch (V3) of the trigeminal nerve carries sensory information from the anterior two-thirds of the tongue, including pain and temperature sensations (but not taste).

Question 41

Allison suffers from Bell's palsy, causing facial paralysis on one side. Which cranial nerve is affected? | *Explain your answer.*

Answer 41

Facial Nerve (CN VII) ## Footnote Bell's palsy is caused by **damage or inflammation of the Facial Nerve** (Cranial Nerve VII), which controls facial muscle movements. When affected, it leads to sudden weakness or paralysis on one side of the face.

Question 42

# Olfactory Nerve (CN I) Impairment A patient reports that they can no longer smell their favorite foods and perfumes. What condition is this?

Answer 42

Anosmia | – the complete or partial loss of smell.

Question 43

# Olfactory Nerve (CN I) Impairment A person smells burning rubber even though there is nothing burning nearby. What condition might they have?

Answer 43

Dysosmia | – experiencing unpleasant or strange odors that occur spontaneously.

Question 44

# Olfactory Nerve (CN I) Impairment A patient complains that they have trouble detecting faint scents, such as flowers or mild spices. What condition do they likely have?

Answer 44

Hyposmia | – decreased sense of smell, difficulty noticing & knowing odors & scents

Question 45

# Olfactory Nerve (CN I) Impairment A person states that their favorite coffee now smells like rotten eggs. What condition is this?

Answer 45

Parosmia | – a distortion of the sense of smell.

Question 46

# Optic Nerve (CN II) Impairments Which condition causes fluid buildup in the eye, leading to increased pressure that can damage the optic nerve?

Answer 46

Glaucoma

Question 47

# Optic Nerve (CN II) Impairments What are tumors that form on the optic nerve, usually benign, called?

Answer 47

Gliomas

Question 48

# Optic Nerve (CN II) Impairments Which condition involves inflammation of the optic nerve, causing pain and vision loss?

Answer 48

Optic neuritis

Question 49

# Oculomotor Nerve (CN III) Impairments What is the condition called when a person sees double images of a single object?

Answer 49

Diplopia

Question 50

# Oculomotor Nerve (CN III) Impairments What is the condition in which the upper eyelid droops or sags, potentially blocking vision?

Answer 50

Ptosis

Question 51

# Trochlear Nerve (CN IV) Impairments Which rare neurological syndrome affects the eye and surrounding area on one side of the face?

Answer 51

Horner syndrome

Question 52

# Trigeminal Nerve (CN V) Impairments Which condition causes intense, sudden facial pain due to damage or irritation of the trigeminal nerve?

Answer 52

Trigeminal Neuralgia

Question 53

# Abducens Nerve (CN VI) Impairments What is the condition in which one or more eye muscles are paralyzed, causing restricted eye movement and double vision?

Answer 53

Paralytic Strabismus