S3_L2: Cranial Nerves Flashcards
Longest cranial nerve
Vagus nerve / CN X
Mediates phonation, swallowing, and elevation of the palate and taste
Vagus nerve / CN X
Innervates viscera of the neck, thorax, and abdomen
Vagus nerve / CN X
Mediates head and shoulder movement and innervates laryngeal muscles
Accessory nerve / CN XI
Mediates tongue movement and shape & innervates intrinsic and extrinsic muscles of the tongue
Hypoglossal nerve / CN XII
When the twelfth cranial nerve has been transected, what is the result?
Hemiparalysis of the tongue
When the tongue protrudes as a result of a lesion to the hypoglossal nerve, the tongue points toward the weak side due to unopposed action of the ___
opposite genioglossus muscle
The hypoglossal nerve exits the skull via the ___
hypoglossal canal
The hypoglossal nerve is a pure general somatic efferent (GSE) nerve arising from the hypoglossal nucleus of the ___.
medulla oblongata
Paralysis of this muscle results in difficulty in turning the head to the side opposite the lesion
sternocleidomastoid muscle
Paralysis of this muscle results in a shoulder droop and the inability to shrug the ipsilateral shoulder
Trapezius muscle
Lesions of the CN XI / accessory nerve result in the paralysis of what 3 structures?
- Sternocleidomastoid
- Trapezius
- Larynx
The cranial division of the accessory nerve arises from the ___ of the medulla oblongata
nucleus ambiguus
The spinal division of the accessory nerve arises from the ventral horn of ___.
cervical segments C1-C6
Which division of the accessory nerve innervates the sternocleidomastoid and trapezius muscles?
Spinal division
Which division of the accessory nerve innervates the intrinsic muscles of the larynx via the inferior recurrent laryngeal nerve with the exception of the cricothyroid muscle?
Cranial division
The accessory nerve / CN XI contains the ___ component
special visceral efferent (SVE)
Predominantly a sensory nerve that mediates taste, salivation and swallowing
Glossopharyngeal nerve / CN IX
Which 3 cranial nerves all exit the skull via the jugular foramen?
- CN IX / glossopharyngeal
- CN X / vagus
- CN XI / accessory
Mediates facial movements, taste, salivation, and lacrimation
Facial nerve / CN VII
Pure general somatic efferent (GSE) nerve that innervates the lateral rectus muscle which abducts the eye
Abducens nerve / CN VI
The abducens nerve arises from the abducens nucleus of the ___.
Caudal pons
Innervates muscles of mastication and mediates general sensation from the face, eye and nasal and oral cavities
Trigeminal nerve / CN V
Longest intracranial nerve
Trochlear nerve / CN IV
What are the movements of the superior oblique muscle?
Depresses, intorts and abducts the eye / Turning the eyeball downward and laterally
Pure general somatic efferent (GSE) nerve that innervates the superior oblique muscle
Trochlear nerve / CN IV
The trochlear nerve arises from the ____ nucleus of the midbrain
Contralateral trochlear
Paralysis of this nerve results in extorsion of the eye and weakness of downward gaze, vertical diplopia, and head tilting
Trochlear nerve / CN IV
Which 3 cranial nerves are entirely sensory?
- CN I / olfactory
- CN II / optic
- CN VIII / vestibulocochlear
Which 5 cranial nerves are entirely motor?
- CN III / oculomotor
- CN IV / trochlear
- CN VI / abducens
- CN XI / accessory
- CN XII / hypoglossal
Which 4 cranial nerves are both sensory and motor nerves?
- CN V / trigeminal
- CN VII / facial
- CN IX / glossopharyngeal
- CN X / vagus
TRUE OR FALSE: The cranial nerves have central motor and/or sensory nuclei within the brain and peripheral nerve fibers that emerge from the brain and exit from the skull to reach their effector or sensory organs.
True
What are the special visceral afferent sensations?
Smell and taste
What are the special somatic afferent sensations?
Hearing, balance, vision
What do the general visceral efferent nerves supply?
Glands and smooth muscles (via parasympathetic innervation)
What do the special visceral efferent nerves supply?
Branchial arch striated muscles
Which 4 cranial nerves exit the skull via the superior orbital fissure?
- Oculomotor
- Trochlear
- Ophthalmic division of trigeminal nerve
- Abducens
Which tongue muscle is not innervated by the hypoglossal nerve?
Palatoglossus muscle
Enumerate the 4 cranial nerves with general visceral efferent components and their corresponding GVE nuclei
- Oculomotor, Edinger-Westphal nucleus
- Facial, Superior salivatory and lacrimal nuclei
- Glossopharyngeal, Inferior salivatory nucleus
- Vagus, dorsal motor nuclei
The general visceral motor nuclei form the cranial outflow of the ___ portion of the autonomic nervous system
parasympathetic
The maxillary division of the trigeminal nerve exits the skull via the (1)___, while the mandibular division exits via the (2)___.
- Foramen rotundum
- Foramen ovale
The only cranial nerve that projects directly to the forebrain
Olfactory / CN I