Cranial Nerves (Ch. 15) Flashcards

1
Q

Cranial Nerves: Overview

A

Part of PNS

Sensory, motor, and parasympathetic nerve fibers that innervate the head and viscera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where do cranial nerves originate?

A

Brain or brainstem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How are the cranial nerves named?

A

Named in order, from anterior to posterior, where they emerge from the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How many cranial nerve (pairs) are there?

A

12 pairs (CN 1 - CN 12)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How many sensory, motor, and mixed nerve pairs exist?

A

3 pairs of sensory nerves
5 pairs of motor nerves
4 pairs of mixed nerves (both sensory and motor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

List all 12 cranial nerves in order (CN 1 - CN 12)

A
  1. Olfactory (CN 1)
  2. Optic (CN 2)
  3. Oculomotor (CN 3)
  4. Trochlear (CN 4)
  5. Trigeminal (CN 5)
  6. Abducens (CN 6)
  7. Facial (CN 7)
  8. Vestibulocochlear (CN 8)
  9. Glossopharyngeal (CN 9)
  10. Vagus (CN 10)
  11. Spinal Accessory (CN 11)
  12. Hypoglossal (CN 12)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the mnemonic for the cranial nerves?

A
On [Olfactory (CN 1)]
On [Optic (CN 2)]
On [Oculomotor (CN 3)]
They [Trochlear (CN 4)]
Traveled [Trigeminal (CN 5)]
And [Abducens (CN 6)]
Found [Facial (CN 7)]
Voldemort [Vestibulocochlear (CN 8)]
Guarding [Glossopharyngeal (CN 9)]
Very [Vagus (CN 10)]
Secret [Spinal Accessory (CN 11)]
Horcruxes [Hypoglossal (CN 12)]
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which 2 cranial nerves attach to the forebrain?

A

Olfactory (CN 1) and Optic (CN 2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where do the rest of the cranial nerves attach?

A

At the brainstem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which is the only cranial nerve to extend past the head and neck?

A

Vagus nerve (CN 10)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 3 axons cranial nerves can carry?

A
Sensory axons (S)
Motor axons (M)
Both axons (B)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which 3 cranial nerves carry sensory axons?

A

Olfactory (CN 1)
Optic (CN 2)
Vestibulocochlear (CN 8)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which 5 cranial nerves carry motor axons?

A
Oculomotor (CN 3)
Trochlear (CN 4)
Abducens (CN 6)
Spinal Accessory (CN 11)
Hypoglossal (CN 12)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which 4 cranial nerves carry both sensory and motor axons?

A

Trigeminal (CN 5)
Facial (CN 7)
Glossopharyngeal (CN 9)
Vagus (CN 10)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What’s the mnemonic for determining which cranial nerves carry S, M, or B axons?

A
Some [Olfactory (CN 1)]
Say [Optic (CN 2)]
Money [Oculomotor (CN 3)]
Matters [Trochlear (CN 4)]
But [Trigeminal (CN 5)]
My [Abducens (CN 6)]
Brother [Facial (CN 7)]
Says [Vestibulocochlear (CN 8)]
Big [Glossopharyngeal (CN 9)]
Brains [Vagus (CN 10)]
Matter [Spinal Accessory (CN 11)]
Most [Hypoglossal (CN 12)]
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

3 Sensory Cranial Nerves

A

Olfactory (CN 1), Optic (CN 2), Vestibulocochlear (CN 8)

Innervation for special sensory structures (smell, vision, equilibrium, and hearing)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Olfactory Nerve (CN 1) [S]

A

Sensory: olfaction (smell)
Origin: olfactory epithelium of nose (terminate in posterior olfactory cortex)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Optic (CN 2) [S]

A

Technically not a nerve but a brain tract (we still call it a nerve)

Sensory: vision
Origin: retina of eye (terminal in primary visual cortex [posterior part of occipital lobe])

19
Q

Vestibulocochlear (CN 8) [S]

A

Sensory: hearing and balance (equilibrium)
Origin: inner ear, enters brain stem at pons

20
Q

5 Motor Cranial Nerves

A

Oculomotor (CN 3), Trochlear (CN 4), Abducens (CN 6), Spinal Accessory (CN 11), and Hypoglossal (CN 12)

Somatic motor fibers to skeletal muscles of eye, neck/back, and tongue

21
Q

Oculomotor (CN 3), Trochlear (CN 4), Abducens (CN 6) [M]

A

Oculomotor (CN 3):

  • -origin: midbrain
  • -also parasympathetic

Trochlear (CN 4):
–origin: midbrain

Abducens (CN 6):
–origin: pons

Fxn: all of these are primarily motor nerves to extrinsic eye muscles

22
Q

Problems with Eye Innervation

A

When the nerve(s) that control the muscles that move the eye are damaged, lots of potential issues. Conditions include strabismus (eyes not parallel), ptosis (drooping eyelids), and diplopia (double vision)

23
Q

Spinal Accessory Nerve (CN 11) [M]

A

Motor nerve to trapezius and sternocleidomastoid muscles

Origin: rootlets at cervical region of spinal cord

24
Q

Hypoglossal (CN 12) [M]

A

(Hypo = below; global = tongue)

Motor to tongue muscles
Origin: medulla oblongata

25
Q

4 Mixed Cranial Nerves (sensory and motor)

A

Trigeminal (CN 5), Facial (CN 7), Glossopharyngeal (CN 9), and Vagus (CN 10)

Mixed nerves: sensory innervation to face, mouth, and viscera and also motor innervation to pharyngeal arch muscles (chewing, facial expression)

26
Q

Trigeminal (CN 5) [B]

A

3 branches: V1 (ophthalmic), V2 (maxillary), V3 (mandibular)

Motor: V3 only
–muscles of mastication

Sensory: V1, V2, and V3
–somatic sensory for face, oral cavity, nasal cavity, anterior 2/3 of tongue (NOT taste)

Origin: sensory receptors to pons

27
Q

Facial (CN 7) [B]

A

Somatic motor: muscles of facial expression (5 major motor branches)

Visceral Motor (parasympathetic)
--lacrimal gland (tears), submandibular and sublingual salivary glands (digestion), + nasal and palatine glands

Sensory: anterior 2/3 of tongue, small patch at ear for somatic sensory

Origin: pons

28
Q

Glossopharyngeal (CN 9) [B]

A

Somatic motor: stylopharyngeas muscle (swallowing)

Visceral motor (parasympathetic): parotid salivary gland (involved with digestion)

Sensory: general visceral sensory, taste posterior 1/3 of tongue

Origin: medulla oblongata

29
Q

Vagus (CN 10) [B]

A

Somatic motor: larynx and pharyngeal muscles

Visceral motor (parasympathetic): thoracoabdominal viscera through 2/3 of the intestines, regulates HR, breathing, and digestive system activity

Sensory: external auditory meatus (EAM) and laryngopharynx. Also visceral sensory form most thoracoabdominal viscera

Origin: medulla oblongata

Vagus (aka the wanderer) is the only cranial nerve to extend beyond head/neck!

30
Q

Summary: Cranial nerves

A

3 sensory: olfactory (CN 1), optic (CN 2), vestibulocochlear (CN 8)
5 motor: oculomotor (CN 3), trochlear (CN 4), abducens (CN 6), spinal accessory (CN 11), and hypoglossal (CN 12)
4 mixed (sensory and motor): trigeminal (CN 5), facial (CN 7), glossopharyngeal (CN 9), and vagus (CN 10)

Know where they come from and where they innervate!

31
Q

Innervation of Tongue

A

Taste: vagus (CN 10), glossopharyngeal (CN 9), facial (CN 7, via chorda tympani)

Somatic Sensation: vagus (CN 10), glossopharyngeal (CN 9), mandibular and lingual nerves (CN V3)

Note: posterior 1/3 of tongue all glossopharyngeal (CN 9)

32
Q

Visceral Motor (parasympathetic)

A

Oculomotor (CN 3): pupils (eye)
Facial (CN 7): lacrimal and salivary glands
Glossopharyngeal (CN 9): salivary glands (parotid)
Vagus (CN 10): thoracoabdominal organs

33
Q

What’s the CN 1 nerve?

A

Olfactory

34
Q

What’s the CN 2 nerve?

A

Optic

35
Q

What’s the CN 3 nerve?

A

Oculomotor

36
Q

What’s the CN 4 nerve?

A

Trochlear

37
Q

What’s the CN 5 nerve?

A

Trigeminal

38
Q

What’s the CN 6 nerve?

A

Abducens

39
Q

What’s the CN 7 nerve?

A

Facial

40
Q

What’s the CN 8 nerve?

A

Vestibulocochlear

41
Q

What’s the CN 9 nerve?

A

Glossopharyngeal

42
Q

What’s the CN 10 nerve?

A

Vagus

43
Q

What’s the CN 11 nerve?

A

Spinal Accessory

44
Q

What’s the CN 12 nerve?

A

Hypoglossal