• What nerve is indicated?
• What number is it?
• Where does it exit the skull? What bone?
• Is it sensory, motor or both? 
• What would be the result of an injury to this nerve?
• [image]

• The nerve indicated is the OLFACTORY NERVE I
• The olfactory nerve is nerve number 1
• It exits the skull at the cribriform plate of the ethmoid bone.
• It is SENSORY
• Injury would result in ANSOMIA, partial of total loss of the ability to smell. 
• [image]

• What nerve is indicated?
• What number is it?
• Where does it exit the skull, what bone?
• Is it sensory, motor or both? 
• What would be the result of an injury to this nerve?
• [image]

• The Nerve indicated is the OPTIC NERVE
• It is nerve number II
• It exits the skull at the OPTIC FORAMEN/CANAL of the sphenoid bone
• It is SENSORY
• Injury would result in blindness to the eye serviced by that nerve. Damage to distal pathways would result in partial visual loss.

 [image]

• What nerve is indicated?
• What number is it?
• Where does it exit the skull?
• Is it sensory, motor or both? 
• What would be the result of an injury to this nerve?
• [image]

• The nerve indicated is the OCULOMOTOR NERVE
• It is number three III
• It exits the skull at the SUPERIOR ORBITAL FISSURE
• It is a MOTOR nerve
• Injury results in 
• Inability to move the eye up or inward. 
• (innervates medial rectus & superior rectus)
• At rest the eye turns laterally/"lazy eye"
• Double vision
• Upper eyelid droops
• innervates levator muscle for eyelid
• Diffulty with close range focusing due to inability to constrict pupil. 
• [image]

• What nerve is indicated? 
• What number is it? 
• Where does it exit the skull? 
• Is it sensory, motor or both? 
• What would be the result of an injury to this nerve?

 [image]

• The nerve indicated is the TROCHLEAR NERVE
• It is nerve number IV
• It exits the skull at the SUPERIOR ORBITAL FISSURE of the sphenoid
• It is a MOTOR NERVE
• Injury would result in:
• DOUBLE VISON
• Reduced ability to rotate the eye DOWN & OUT
• Remember: Trochlear means pully, the trochlear nerve activates the superior oblique muscle of the eye, which acts like a pulley, pulling the eye down and out. 

[image]

What nerves exit the skull at the superior orbital fissure?

What is the overall function of nerves that exit the skull there?

[image]

• the oculomotor nerve
• the trochlear nerve
• the opthamalic branch of the trigeminal nerve
• the abducens nerve 
• all exit the skull at the superior orbital fissure. 
• THREE CONTROL EYE MOVEMENT (ocolular motor, trochlear, abducens)
• ONE CONTROLS EYE SENSATION (trigeminal)
• [image]

• What nerve is indicated? 
• What number is it? 
• What are its branches?
• Is each part of it sensory, motor or both? 
• Where does each exit the skull? 
• What makes this an easy to identify nerve?
• [image]

• This is the TRIGEMINAL NERVE V
• It is nerve number five
• It's branches are 
• V₁ Opthamalic - Sensory
• V₂ Maxillary - Sensory
• V₃ Mandibular- Mixed
• OVERALL - BOTH SENSORY & MOTOR

• The OPTHAMALIC BRANCH exits the skull at the SUPERIOR ORBITAL FISSURE
• The MAXILLARY BRANCH exits the skull at the FORAMEN ROTUNDUM  
• (Max & Round, both indicate largeness)
• The MANDIBULAR BRANCH exits the skull at the FORAMEN OVALE
•  This nerve is the largest cranial nerve

[image]

• Name each nerve, nerve branch or exit point indicated.
• Indicate whether each nerve is motor/sensory/both.
• We did not review number 12. It is the trigeminal ganglion.
• The nerves are, for the most part, not number in the correct order. 
• You may wish to list them by their cranial nerve order as opposed to the order given. 

[image]

1. Olfactory Nerve NI - Sensory

8. Cribriform plate - exit point of olfactory nerve

2. Optic Nerve NII -Sensory

3. Oculomotor Nerve NIII -Motor

5. Trochlear Nerve (smallest) NIV - Motor

6. Trigeminal - NV -Both

9. Opthamalic Branch V_{1 - S}

10.Maxillary Branch V_{2 - S}

11.Mandibular Branch V_{3 - B}

12. Trigeminal Ganglion

4. Abducens Nerve-NVI-Motor

13. Facial Nerve -NVII - Both

14. Vestibulocochlear Nerve NVIII -Sensory 

15. Glossopharyngeal Nerve  NIX - Both

16. Vagus Nerve NX - Both

7. Accessory Nerve NXI -Motor

17. Hypoglossal Nerve NXII - Motor 

[image]

2

The perisosteal layer is adherant to the brain case. 

The meningeal layer lies closer to the brain.

Falx cerebri

Tentorium cerebelli

Falx cerebelli

note: a falx is a short Roman sword resembling a sickle. It is a pretty good resemblance to the two dural infoldings it names.

 [image]

[image]

Label the dural partitons/infoldings indicated by numbers 1-3.

[image]

1. Falx cereberi

2. Tentorium cerebelli

3. Falx cerebelli

[image]

Which dural partition/infolding is indicated?

[image]

Falx cerebri

[image]

Which dural partiton/infolding is indicated?

[image]

Which dural partition/infolding is indicated?

[image]

What dural strurture is indicated by the question mark?

[image]

Superior Sagittal Sinus

[image]

What dural structure is indicated by the question mark?

[image]

The Straight Sinus

[image]

What sinuses are indicated by letters C, F and H? 

[image]

C: Transverse Sinus

F: Sigmoid Sinus

H: Straight Sinus

[image]

What sinuses converge at the site referred to as the "confluence of sinuses", point E in the illustration below?

[image]

• CONFLUENCE OF SINUSES
• superior sagittal sinus
• straight sinus
• transverse sinuses
• occipital sinus
•  we did not speak about this sinus, but all sources that refer to the confluence of sinuses include it. 
• [image]

It is deoxygenated, hence its blood color

It is enroute to the heart.

Dural Sinuses 

[image]

Into the internal jugular vein

[image]

1. Superior Sagittal Sinus
2. Inferior Sagittal Sinus
3. Transverse Sinus
4. Sigmoid Sinus 
5. Straight Sinus

[image]

• What would be the result of an injury to the trigeminal nerve in each branch?
• [image]

INJURY TO TRIGEMINAL NERVE

[image]

• OPTHALMIC BRANCH: (sensory)
• loss of sensation/pain in the eye, cornea, nasal cavity, skin of forehead, upper eyelid, eyebrow and nose.
• MAXILLARY BRANCH: (sensory)
• loss of sensation/pain of lower eyelid, upper lip, gums, cheek, nose,palate, and pharynx
• Tic douloureux, painful inflammation of the nerve
• MANDIBULAR BRANCH: (both)
• loss of sensation/pain from lower gums, teeth and lip, palate and part of tongue, 
• Tic douloureux, painful inflammation of the nerve
• loss of motor control over muscles of mastication 

Damage to which nerve results in a cross-eyed presentation?

[image]

Abducens Nerve VI

unable to abduct the eye, the eye rotates medially

Injury to which nerve can cause double vision?

[image]

Oculomotor Nerve III

other sources include the Trochlear nerve in this but our text book specifies the oculomotor

Injury to which nerve can lead to partial blindness?

[image]

The Optic Nerve II

Vision loss would not be complete unless boss nerves were injured

Injury to which nerve can cause deafness?

[image]

Vestibulochoclear VIII

the ear has curves like the number 8

Damage to which nerve can cause Bell's Palsy?

[image]

Facial Nerve VII

Picture a number 7 across the face

[image]

Damage to what nerve would impair a person's ability to look at their neighbor's exam?

[image]

Trochlear Nerve IV

because one would be unable to rotate the eye down & out

Damage to which nerve might result in a "lazy eye"

[image]

Damage to which nerve might result in a difficulty focusing on close objects?

[image]

Oculomotor Nerve III

This nerve is responsible for contracting the pupil and that allows focus.

Damage to which nerve may result in a drooping upper eyelid?

[image]

Oculomotor Nerve III

because it innervates the levator palpebrae muscle, the upper eyelid

Which 3 nerves allow us to taste? 

[image]

• Facial VII (anterior 2/3 of tongue)
• Glossopherangeal IX (posterior 1/3)
• Vagus X (pharyngeal taste) 

Which cranial nerve stimulates digestive organs?

[image]

Vagus Nerve X

The vagus nerve is also responsible for sensing "fullness" during or after a meal. 

• What nerve is indicated?
• What number is it?
• Where does it exit the skull?
• Is it sensory, motor or both? 
• What would be the result of an injury to this nerve?

[image]

• Abducens Nerve VI
• Number 6
• It exits the skull at the superior orbital fissure
• It is MOTOR
• INJURY 
• Inability to abduct the eye
• Cross-eyed appearance

• What nerve is indicated?
• What number is it?
• It is sensory, motor or both?
• Where does it exit the skull?
• What would injury to this nerve result in?

[image]

• Vestibulocochlear Nerve VIII
• SENSORY
• It exits the skull at the INTERNAL AUCUSTIC MEATUS
• INJURY to the Vestibulocochlear nerve can results in:
• Deafness or problems with hearing
• Dizziness
• Problems with balance and nausea. 

• What nerve is indicated?
• What number is it? 
• It is sensory, motor or both?
• Where does it exit the skull?
• What would injury to this nerve result in?

[image]

• This is the ACCESSORY NERVE XI (or spinal accessory)
• It is number 11
• MOTOR
• It exits the skull through the JUGULAR FORAMEN
• INJURY:
• Head would turn towards injured side
• Shrugging the shoulders would be difficult
• This nerve controls the sternocleidomastoid and trapezius muscles
• It also aids the vagus nerve by innervating voluntary swallowing muscle
• Vocal cord use might be impaired. 

• What nerve is indicated?
• What number is it?
• It is sensory, motor or both?
• Where does it exit the skull?
• What would injury to this nerve result in?
• [image]

• Facial Nerve VII
• SEVEN
• BOTH SENSORY & MOTOR
• Exits the skull at the STYLOMASTOID FORAMEN via the internal acoustic meatus
• INJURY:
• Bell's Palsy
• Facial muscle paralysis
• inability to "make face"
• drooping of affected side of face 
• difficulty eating and speaking 
• continual "weeping" on affected side
• Inability to completely close eye
• Problems with salvia secretion
• Partial loss of taste sensation

• What nerve is indicated?
• What number is it?
• It is sensory, motor or both?
• Where does it exit the skull?
• What would injury to this nerve result in?
• [image]

• Glossopharyngeal Nerve IX
• note: glosso- tongue; phrayngeal - phraynx or throat
• NINE
• BOTH SENSORY & MOTOR
• Exits the skull at the JUGULAR FORAMEN
• INJURY:
• imparied swallowing
• impairs taste on posterior 1/3 of tongue particularly bitter or sour
• problems regulating blood oxygen and CO2 levels  
• salivary impairment

• What nerve is indicated?
• What number is it?
• It is sensory, motor or both?
• Where does it exit the skull?
• What would injury to this nerve result in?

[image]

• Hypoglossal Nerve XII
• TWELVE
• MOTOR
• Exits at the Hypoglossal Canal
• INJURY
• difficulty in speech and swallowing
• problems with protusion of tongue
• deviation of tongue towards affected side
• tongue atrophy

• What nerve is indicated?
• What number is it?
• It is sensory, motor or both?
• Where does it exit the skull?
• What would injury to this nerve result in?
• [image]

• Vagus Nerve X
• TEN
• BOTH MOTOR & SENSORY
• Exits at the JUGULAR FORAMEN
• INJURY
• hoarsness and loss of voice
• difficulty swallowing
• impaired digestive system
• inability to feel external ear
• no taste when swallowing (in pharynx)
• visceral activity would be impaired
• cardiac
• pulmonary 
• digestive
• blood pressure & chemistry
• death can result

What are the branches of the FACIAL  NERVE VII

(these were in the book, but not on our lab work so they probably won't come up)

Vagus Nerve X

Glossopharyngeal IX

Hypoglossal XII

Accessory XI (by joining with Vagus)

Whic nerve most affects our ability to cry?

[image]

Facial Nerve VII

(this is the only one mentioned in the book but other sources indicate the Trigeminal nerve as well)

think: when the lake of tears (in the corner of the eye) overflows, it flows down ones face. 

What nerve is responsible for the following:

• the facial sensation of pressure
• taste on the anterior 2/3 of the tongue
• lacrimal gland, glands of the nasal cavity, salivary gland
• the movements of facial expression

• What cranial nerve, if injured, might effect our ability to speak by impairing our ability to use our tongue?
• What cranial nerve, if injured, might affect our ability to speak by impairing our ability to use our vocal cords?

Hypoglossal Nerve XII

• The hypo, means below, and glossal, tongue. 
• This motor nerve controls the muscles of the tongue. 

Accessory Nerve XI

• Innervates the vocal cords.
• The accessory nerve gives motor control in the areas where one would wear the ACCESSORY of a scarf. 

• Note: The FACIAL NERVE VII, which controls the muscles of the mouth, can also impair speech. 

Damage to what nerve would result in an inability to chew?

[image]