4- Cranial Nerves Flashcards
How many pairs of nerve are emerging directly from the brain/brain stem considered Cranial Nerves?
12 pairs
The 12 pairs of cranial nerves that emerge directly from the brain or brain stem travel through what of the cranium?
they travel through foramina in the cranium
What two kind of information do cranial nerves carry?
They carry either: SENSORY or MOTOR impulse. or sometimes a combination of both.
How are the 12 pairs of cranial nerves ordered?
1 being the most Rostal and 12 the most Caudal. Rostral means pertaining to the “beak” or “beak-like”
Name and type of cranial nerve of: CN I
Olfactory SENSORY
Name and type of cranial nerve of: CN II
Optic SENSORY
Name and type of cranial nerve of: CN III
Oculomotor MOTOR
Name and type of cranial nerve of: CN IV
Trochlear MOTOR
Name and type of cranial nerve of: CN V
Trigeminal BOTH
Name and type of cranial nerve of: CN VI
Abducent MOTOR
Name and type of cranial nerve of: CN VII
Facial BOTH
Name and type of cranial nerve of: CN VIII
Vestibulocochlear SENSORY
Name and type of cranial nerve of: CN IX
Glossopharyngeal BOTH
Name and type of cranial nerve of: CN X
Vagus BOTH
Name and type of cranial nerve of: CN XI
Spinal Accessory MOTOR
Name and type of cranial nerve of: CN XII
Hypoglossal MOTOR
CN I:
Name
Function
Origin
Path & Terminal
Notes
Name: Olfactory Nerve
Function: Special sense of smell
Origin: Frontal Lobe
Path & Terminal: leads to the Ethmoid and expands into Olfactory bulbs
Notes: Olfactory bulbs give off multiple nerve endings that pierce through the Cribiform plate.
- In the Nasal cavity the Olfactory nerve endings possess cilia that are covered in mucous
- Those cilia are stimulated by the scent of molecules dissolved in the mucous that then is transmitted to the brain
CN II:
Name
Function
Origin
Path & Terminal
Notes
Name - Optic Nerve
Function - Special Visual sense
Origin- Decussates at the OPTIC CHIASM
Path & Terminal- travels through the Optic Canal and is continous with the Retina of the Eye
Notes- Decussation at the Optic Chiasm means that the Left Optic Nerve will receive stimulus from the Left visual field and the Right will receive from the righ visual field
CN III:
Name
Function
Origin
Path & Terminal
Notes
Name- Oculomotor
Function - Motor innervation to: Superior Rectus, Medial Rectus, Inferior Rectus, Inferior Oblique, Levator Palpabrae superioris, and Sphincter pupillae
Origin- Midbrain
Path & Terminal- exits the cranium via Superior Obital Fissures and innervates the muscles of the eye
Note- “down & out” if injured affects the eyeballs position of lateral and downward gaze.
-also controls the constriction of the pupils.
CN IV:
Name
Function
Origin
Path & Terminal
Notes
Name- Trochlear
Function - Innervation of the superior oblique of the eye
Origin- Midbrain
Path & Terminal- exits the cranium via the Superior Orbital fissure to innervate superior oblique
Notes- if damaged it affects the eyeballs ability to restrict the drift towards the nose.
CN V:
Name
Origin(1)
Terminal(1)
Branches(3)
Name - Trigeminal
Origin- Pons
Terminal- Trigeminal Ganglion
Branch #1: CN V1- Ophthalmic
Branch #2 CN V2- Maxillary
Branch #3 CN V3- Mandibular
How does CV1 exit the cranium and its Function?
CV1 exits the cranium via Superior Orbital fisssure
Function: provides sensation to the cornea, superior forehead and scalp, eyelids, nose, and nasal cavity
How does CV2 exit the cranium and it Function?
CV2 exits the cranium via Foramen Rotundum
Function: provides sensation to the skin and teeth along the maxilla as well as to the palate and surrounding mucosa
How does CV3 exit the cranium and its Function?
CV3 exits the cranium via Foramen Ovale
Function: provides sensation to the skin along the mandible as well as the front 2/3 of the tongue
-also provides motor innervation to the muscles of Mastication (Temporalis, Masseter, Medial/Lateral Pteragoids), Mylohyoid, Anterior Digastric, Tensor Veli Palantini, and Tensor Tympani