Cranial Nerves Worksheet

Question 1

How does the numbering of the cranial nerves differ from that of the spinal nerves?

Answer 1

roman numerals I - XII

Question 2

List the cranial nerves with their numbers and names

Answer 2

I Olfactory, II Optic, III Oculomotor, IV Trochlear, V Trigeminal, VI Abducens, VII Facial, VIII Vestibulo-cochlear, IX Glossopharyngeal, X Vagus, XI Accessory, XII Hyperglossal.

Question 3

Write a mnemonic for remembering the cranial nerves - own or other

Answer 3

On Old Olympus Towering Top A Fin And German Veined Some Hops

Question 4

Are cranial nerves part of the CNS or PNS

Answer 4

PNS - but I, II, V more accurately CNS come directly from the brain

Question 5

Which cranial nerves carry parasympathetics fibres?

Answer 5

Oculomotor, facial, glossopharyngeal, vagus = CN III, VII, IX, X

Question 6

Which cranial Nerves emerge from:

a) Medulla
b) Pons
c) Midbrain
d) Forebrain

Answer 6

a) CN IX, CN X, CN Xi, CN XII - all have “X’s”
b) CN V trigeminal + 3a - Pons to medullary junction = CN VI, CN VII, CN VIII
c) CN III oculo-motor, CN IV Trochlear
d) CN I + II

Question 7

which cranial nerves pass through the jugular foremen?

Answer 7

CN IX glosso-pharyngeal, CN X Vagus, CN XI Accessory

Question 8

a) Which cranial Nerve is involved in Menieres disease
b) What are the 3 diagnostic symptoms of Menieres Disease?

Answer 8

a) CN VIII Vestibular-cochlear - balance, vertigo from inner ear disorders.
b) sensory, neural hearing loss, vertigo, tinnitus, sense of fullness in the ear - etiology - seems to involve oedema in the labyrinth

Question 9

a) If a patient were to present with one side of face drooping, difficulty controlling muscles on that side, crooked smile, saliva dribbling from one side of mouth what condition would you suspect and which CN might be involved?
b) What other more severe conditions might bring on similar symptom?

Answer 9

a) Bell’s Palsy + Facial Nerve CN VII
b) Viral infection, bacterial infection, herpes simplex, HIV, compound immune systems diseases, stroke, surgery - also CN VII / motor branch - pathway through the parotid gland that may be compressed - this can lead to Bell’s palsy. Extreme case of mumps / parotitus.

Question 10

a) which cranial nerve is primary involved in salivary secretion
b) which other cranial nerve contributes a lesser secretion of saliva

Answer 10

a) CN IX - glossopharyngeal
b) minor glands, CN VII Facial, sublingual, sub mandibular

Question 11

Why might a blow to the head contribute to visual disturbances?

Answer 11

From eyes, cross over at the optic chasma, terminates in visual cortex.in located in the back of the head, occiput area

Question 12

Describe the pathway and type of nerve supply involves in pupil dilations

Answer 12

Oculomotor travels from midbrain via Superior Orbital Fissure to the orbit

Sympathetic travels up the neck, synapses at scg and carries on via carotid plexus as ciliary nerve to dilate the pupil

Question 13

Describe the pathway and type of nerve supply involved in pupil constriction?

Answer 13

Oculomotor CN III - is responsible for the efferent limb of the pupillary reflex - it drives the iris muscles that constrict the pupil. Muscles of the iris - intrinsic

Question 14

Why s the Optic Nerve CN II not actually a cranial nerve anatomically?

Answer 14

Technically part of the CNS, rather than PNS - it is desired from, branching out of the diencephalon - optic stalks - during embryonic development.

Question 15

why might mumps lead to a unilateral facial paralysis?

Answer 15

It is an infection from virus/viral infection. Inflammation of CN VII due to mumps parotitus causes swelling of the salivary glands / parotic glands and restriction to CN VII

Question 16

In the absence of mumps, where might be the most likely cause of cranial nerve damage leading to facial paralysis?

Answer 16

CN VII Facial - any constriction, by inflammation or trauma that causes a disturbance

Question 17

What are the symptoms of trigeminal neuralgia?

Answer 17

chronic pain, sudden jolt of pain, severe pain

Question 18

What do you consider to be the most likely causative factors of trigeminal neuralgia?

Answer 18

Irritation or constriction of the nerve pathway, misalignment of the upper skeletal area. Tooth ache, infection. Contact between artery, vein and nerve - pressure

Question 19

What cranial nerve/s may be involved in asthma?

Answer 19

Lungs are innervated by CN X - Vagus - Parasympathetic supply from the Vagus

Question 20

Which cranial nerve is primarily associated with sensation from the face?

Answer 20

Sensation: trigeminal CN V + motor functions, biting and chewing

Question 21

Which cranial nerve is primarily associated with motor function in the face?

Answer 21

CN VII - Facial Nerve

Question 22

Which cranial nerves are involved in swallowing?

Answer 22

1] Glossopharyngeal CN IX, [2] Hypoglossal CN XII - elevates the larynx and pharynx, [3] Vagus CN X

Question 23

The recurrent laryngeal nerve is a branch of which cranial nerve?

Answer 23

Vagus CN X - supplies the intrinsic muscles of the larynx

Question 24

how long is the recurrent laryngeal nerve in a giraffe and why?

Answer 24

2,4 m / 15 feet. It takes an extreme detour for the long neck

Question 25

Which cranial nerve plays a significant part in drainage of CSF?

Answer 25

CN II Olfactory

Question 26

Which cranial nerves might be involved in squint?

Answer 26

Oculo-motor CN III, Trochlear CN IV, Abducent CN VI,

Question 27

if one eye were persistently directed out laterally, what might be likely factors contributing to this?

Answer 27

lateral rectus, CN VI - directs the gaze laterally - opposite pull - disturbance to innervation of the lateral muscle - the disturbance will be to the CN III

Question 28

if one eye were persistently directed out medially, what might be likely factors contributing to this?

Answer 28

Medial rectus, CN III - directs the gaze medially - opposite pull - disturbance to the medial rectus muscle - the disturbance will be to the CN VI

Question 29

If a patient presented with gradually deteriorating tunnel vision, what factors might you consider to be relevant?

Answer 29

Loss or decreasing of peripheral vision, obstruction to the Optic Nerve CN II, disease, glaucoma, hereditary - Retinitis pigmentosa

Question 30

what is the most common cause of blindness in the world?

Answer 30

Cataract - 15% OVER 50 years of age, also diabetes

Question 31

What systemic conditions might affect eyesight?

Answer 31

Diabetes, Multiple Sclerosis, Hypertension, Meningitis, Thyroidism

Question 32

Which nerves or other structures pass through the superior orbital fissure?

Answer 32

III Oculomotor, IV Trochlear, Trigeminal CN V Trigeminal, VI Abducens, Ophthalmic branch of the CN V

Question 33

What structure/s pass through the foramen lacerum?

Answer 33

Carotid Artery, Carotid Nerve + Vein

Question 34

Which nerve/s are involved in raising the upper eyelid?

Answer 34

Occulomotor Nerve CN III + Facial CN VII

Question 35

Which cranial nerves are involved in chewing?

Answer 35

CN V trigeminal, CN VII facial and CN XII hypo-glossal

Question 36

If a young child has a squint, what factors - neurological or other - would you consider relevant to investigate?

Answer 36

Damage to CN VI Abducens - loss of abduction. Consider double vision assoc. with.

Question 37

Name 3 branches of the Trigeminal Nerve

Answer 37

Ophthalmic (forehead) Maxillary (cheeks) Mandibular (jaw) - both sensory and motor

Question 38

Apart from the Vestibulo-cochlear nerve CN VIII, which other nerves might be involved in acuity of hearing? Explain why.

Answer 38

glossopharyngeal (IX) (middle ear) Facial (VII) (sensory, external ear) Trigeminal (V) (small muscles of the ear) Combination of both motor and sensory nerves to the inner and external ear to receive auditory signals and process them for hearing

Question 39

Into which nerve would a dentist inject anaesthetic in order to anaesthetise your upper teeth?

Answer 39

Sub branches of the maxillary; (inferior alveolar) and mandibular; (superior alveolar) of Trigeminal (V). To numb the lower teeth prior to dental work, the dentist must inject anaesthesia into the lateral wall of the oral cavity at a point prior to where this sensory nerve enters the mandibular foramen.

Question 40

Which nerve might be involved in severe pain in the forehead and superior rim of the orbit?

Answer 40

Ophthalmic division of Trigeminal (V) Sub-divisions; Frontal, Supra-orbital and Supra-trochlear

Question 41

What is the pterygopalatine ganglion, what passes through it and what functions do it affect?

Answer 41

Pterygopalatine ganglion located in Pterygopalatine fossa between lateral pterygoid plates of sphenoid & palatine bones Affects parasympathetic supply to lacrimal travels with Facial CN VII through it. Secretions to face: lacrimal, facial, nasal, salivary, and mucosal.

Question 42

Where is the stylo-mastiod foramen located and what passes through it?

Answer 42

Located on the inferior surface of the petrous temporal bone, between the base of the styloid and mastoid process' Main motor branch of Facial (VII) passes through it.

Question 43

Describe the complex pathway and origins of the Spinal Accessory Nerve CN XI.

Answer 43

Two divisions, cranial and spinal, both motor, pass through Foramen Magna and upper spine, descending to divisions. [1] - cranial from Medulla - provides motor supply to sterno-cleido-mastiod & trapezius m. and [2] - spinal C1 - C4 - provides motor supply to pharynx, larynx & palate. passes though, and joins at the jugular foramen

Question 44

If the patient is presented with dizziness and difficulty with balance and equilibrium, which cranial nerve's) might be involved?

Answer 44

Vestibular-cochlear (VIII) hearing & balance

Question 45

What other factors apart from the cranial nerve involvement might contribute to issues with hearing and balance?

Answer 45

Blocked Eustachian tube, ear infection, inadequate blood supply due to lower blood pressure, Meniere's disease, medication, trauma to the head, inhibrihation

Question 46

If a patient were to present with tinnitus, which cranial nerves might be involved?

Answer 46

Various nerve pathways that may be restricted, infected, pressure - incl. Vestibulo-occulear N, stapedius branch of Facial Nerve CN VII, branch of Trigeminal. Many widely distributed branches of SNS.

Question 47

What other factors might contribute to tinnitus?

Answer 47

Teeth clenching, stress, vascular disturbances, neuritis, exposure to noise, TMJ dysfunction.

Question 48

Which cranial nerve/s might be most affected by restriction in the suboccipital upper cervical region?

Answer 48

Cranial nerves en route to the visual cortex, sympathetic pathway to head and eyes pass through this area. Passing through the Foramen Magnum are the CN XI, spinal cord and vertebral arteries. CN XII is in the area, passing through the Hypoglossal Canal

Question 49

Which cranial nerve/s are involved in digestion

Answer 49

Trigeminal (V) - for muscles of mastication - moving jaw up and down Facial (VII) - submandibular and sublingual salivary glands (for secretion of saliva) Glosso-pharyngeal (IX) - sensation of taste Hypo-glossal (XII) - for tongue movement Vagus (X) - regulation of viscera - assisting contraction of muscles in stomach for digestion Digestion starts in the mouth

Question 50

Which cranial nerve/s supply the ascending colon?

Answer 50

Vagus, CN X

Question 51

Which cranial nerve/s supply the descending colon?

Answer 51

None, Vagus CN X NOT - innervation from the sacrum S2, S3, S4 to descending colon.

Question 52

If the patient presents with persistent, itchy, dry nose, mouth and eyes, what factors would you consider to be most relevant and which nerves would most likely be involved?

Answer 52

Disturbances or restrictions to Facial CN VII, Glosso-pharyngeal CNIX, disturbance to parasympathetic div. of Facial CN VII

Question 53

Which nerve's) pass through the Temporal Bone?

Answer 53

Vestibulo-cochlear (VIII) & Facial (VII) within temporal bone petreous ridge

Question 54

What affect does the Vagus Nerve have on the heart?

Answer 54

3 superior cervical cardiac branches + several inferior cervical cardiac providing Parasympathetic supply to the heart - slows the heart rate down.

Question 55

Which cranial nerves pass through the tentorium?

Answer 55

At the location of the border crossing, cranial nerves III and IV pass through toward the lateral wall of the cavernous sinus + CN II Optic Division

Question 56

Which cranial nerves are involved with lens accommodation and pupil constriction?

Answer 56

Ciliary muscles innervated by parasympathetic fibres travelling with CN III. Constriction is enabled by parasympathetic supply travelling CN III - Oculo-Motor N.

Question 57

would you expect the glandular secretions of the face (nasal, lacrimal, sublingual) to be affected by damage to the facial nerve at the stylo-mastiod foramen? Explain your reasons

Answer 57

No - the parasympathetic branches to the glands of the face branch off within the Facial Canal. The main motor branch emerges at the Stylo-mastoid Foramen

Question 58

Which cranial nerves are purely sensory?

Answer 58

The first two cranial nerves, the olfactory nerve (I) and the optic nerve (II), are purely sensory and innervate the nasal mucosa for the sense of smell (olfaction) and the eye for the sense of sight (vision), respectively.

Question 59

Describe in detail the Optic pathway. Drawing

Answer 59

The optic pathway passes from the retina ( visual images received) at the back of the eye, via the optic nerve, R & L optic nerves meet and partially cross over at the optic chasm, medial fibres from each cross to opposite side, lateral continue on same side. Fibres continue postr. on each side of optic tract, below the thalamus they branch into optic radiations, which continue to the visual cortex within the occipital lobe at the back of the brain.

Question 60

Describe the pathway of CN III, IV & VI

Answer 60

They travel along the floor of the MIDDLE CRANIAL FOSSA on EACH SIDE OF SPHENOID BODY \> entering the POSTERIOR OF THE CAVERNOUS SINUS \> CN III and IV closer to the lateral wall and CN III closer medially. EMERGE TOGETHER FROM ANTERIOR WALL OF CAVERNOUS SINUS and PASS INTO THE ORBIT THROUGH SUPERIOR ORBITAL FISSURE (f2f p200)

Question 61

where is the hypoglossal canal?

Answer 61

The canal in which the hypoglossal nerve (XII) (tongue movement) passes is within the foramen magnum

Question 62

In frontal and maxillary sinuses, which nerve/s transmit the pain?

Answer 62

Pain from constriction by inflammation or trauma around the area - Trigeminal and Facial Nerves.

Question 63

Which cranial nerves might be involved with a child presenting with speech and language difficulty? Explain why in each case.

Answer 63

vestibular-cochlear (VIII) - if hearing is impaired. + glosso-pharyngeal (IV), vagus (X), accessory (XI) & hypo-glossal (XII) for balance, swallowing and speech, muscles of the tongue for movement and word formation. Also consider 'tongue tie' - release connective tissue.

Question 64

What is the carotid nerve and what pathway?

Answer 64

Branch of the Glossopharyngeal N., that runs downward, antr., to the internal carotid artery, communicates with the CN X - innervates carotid body and corotid sinus.

Question 65

Which glands are innervated by the facial nerve VII?

Answer 65

Parotid gland and Lacrimal gland - anterior 2/3 of tongue parasympathetic innervation of the glands of the oral cavity

Question 66

Which Nerve's) pass through the cavernous sinuses?

Answer 66

Oculormotor CN III, Ophthalmic CN VI, Abducens, Trochlear CN IV, Maxillary Nerve Vii and some sympathetic plexus

Question 67

What does diplopia mean?

Answer 67

double vision

Question 68

What does strabismus mean?

Answer 68

squint

Question 69

Which cranial nerve's) supply the parotid gland?

Answer 69

Parasympathetic innervation to the parotid comes from the glossopharyngeal nerve (CN IX) and causes secretion of saliva. The parasympathetic fibres of CN IX originate in the inferior salivatory nucleus in the medulla and travel through the jugular foramen to the inferior ganglion.

Question 70

Which cranial nerve also has roots outside the cranium and where are they?

Answer 70

Accessory Nerve (XI) - which controls the sternocleidomastoid and trapezius muscles of the shoulder and neck, has spinal roots between C1 - C4

Question 71

Which nerve 'assists' the Vagus CN X, and in what function does it do so?

Answer 71

CN XI Accessory (spinal accessory) Nerve - (motor) to pharynx, larynx and palate - in assisting the Vagus. I venture to say that the Glosso-pharyngeal nerve CN IX, also 'assists' the Vagus nerve - the Sensory branch to the carotid sinus and carotid body - located at the bifurcation of the carotid artery, receives sensations related to blood pressure, oxygen and carbon dioxide levels on the blood stream, together with pH levels (an indicator of disease in the body - disease cannot thrive in an alkali body). The carotid branch influences breathing and blood pressure. In terms of the polyvagal theory - I sense that CN IX has a significant role to play, in particular breathing and blood pressure. And further, in monitoring blood pressure, O2 and CO2. These functions are closely related to the functions, sensation and responses of the Vagus nerve - IS this another sensation that the Vagus nerves responds to trigger flight or flight? Or restore rest and digest once the appropriate level of O2 is recorded in the blood? Another vicious circle? Another nerve reported to assist the vagus is the trigeminal nerve CN V - in cold water deep dive - it receives sensations from the face and transmits to the vagus to reduce heart rate, conserve oxygen and in so doing kicks the parasympathetic response into play by calming and restoring balance to the ANS.

Question 72

Which extrinsic muscles to the eye are supplied by CN VI

Answer 72

The extraocular muscles are innervated by lower motor neurons that form three cranial nerves: the abducens, the trochlear, and the oculomotor. The abducens nerve (cranial nerve VI) exits the brainstem from the pons-medullary junction and innervates the lateral rectus muscle.

Question 73

Which extrinsic muscles to the eye are supplied by CN IV

Answer 73

The trochlear nerve (IV) exits from the caudal portion of the midbrain and supplies the superior oblique muscle. In distinction to all other cranial nerves, the trochlear nerve exits from the dorsal surface of the brainstem and crosses the midline to innervate the superior oblique muscle on the contralateral side.

Question 74

Which extrinsic muscles to the eye are supplied by CN III

Answer 74

Oculomotor (Motor) - Innervates the majority of the extraocular muscles (levator palpebrae superioris, superior rectus, inferior rectus, medial rectus and inferior oblique). Parasympathetic - Supplies the sphincter pupillae and the ciliary muscles of the eye.

Question 75

Which nerves supply the intrinsic muscles of the eye?

Answer 75

The oculomotor nerve (the third cranial nerve; CN III) has three main motor functions: Innervation to the pupil and lens (autonomic, parasympathetic) Innervation to the upper eyelid (somatic) Innervation of the eye muscles that allow for visual tracking and gaze fixation (somatic)

Question 76

Where is the Vagus nerve most likely to be compressed or disturbed?

Answer 76

Jugular Foramen - back of the head and neck

Question 77

Which nerve emerges through the supraorbital notch?

Answer 77

The supraorbital nerve (which is a direct continuation of the frontal nerve - part of ophthalmic branch of trigeminal (V) Supplies sensory innervation to the nasal and middle two-thirds of the upper eyelid

Question 78

What type of nerve fibres are involved in lacrimal gland secretion and which cranial nerve's carry the nerve supply?

Answer 78

The lacrimal gland is innervated by the lacrimal nerve - smallest branch of the ophthalmic division - trigeminal nerve (CN V) Also receives parasympathetic autonomic nerve fibres from the greater petrosal nerve - branch of facial nerve (CN VII)

Question 79

Why might the eyes be affected by injuries and tension in the upper thoracic spine?

Answer 79

Muscle tension in the upper back, neck and shoulders can lead to headaches or problems with your vision, as the flow of blood is restricted to your eyes. In the upper cervical spine (C1-C2), injuries can cause symptoms such as nerve and tendon irritation and vertebrobasilar insufficiency with associated visual disturbances or motor reflexes of the eyes..

Question 80

Which cranial nerve/s might be involved in torticollis? Explain why.

Answer 80

The accessory nerve -CN XI. It has a purely somatic motor function, innervating the sternocleidomastoid and trapezius muscles. The action of the sternocleidomastoid is to perform contralateral rotation, ipsilateral inclination, and flexion of the head. Other muscles of the region involved in torticollis include the splenius, the trapezius, the scapula, the scalenes, and the platysma. The platysma is innervated by the cervical branch of facial nerve (CN VII)\_.