Lecture 20: Cranial Nerves - B Flashcards
_____: Organ made of nerve fibers (+ connective tissue) that connects CNS to periphery (muscles, glands, skin)
Nerve
How many spinal nerves serve the body? cranial?
31 spinal nerves (body)
12 cranial nerves (head and neck)
The vagus nerve also supplies the ___ and ___
thorax and abdomen
Most cranial nerve nuclei receive ___ innervation from the cortex
A. bilateral
B. unilateral
A. bilateral
True or False: If one has an UMN lesion, ipsilateral muscles are paralyzed. However, if one has a LMN lesion, muscle function is intact
False
LMN lesion = ipsilateral m paralyzed
UMN lesion = function intact
True or False: The number of cranial nerves decreases rostral to caudal
False - there’s an INCREASE
The medial cranial nerves tend to have ____ function while the lateral ones have ____ function
motor; sensory
Which CN’s have sensory function?
fdf
Which CN’s have motor function?
fdds
Which CN’s have both motor and sensory function?
Which four CN’s are found in the medulla?
CN 9-12
Which three CN’s are found in the pons?
CN 5-7
Which two CN’s are found in the midbrain?
Oculomotor and Trochlear
Which CN innervates the superior, inferior & medial rectus, inferior oblique
A. CN 3
B. CN 4
C. CN 5
D. CN 6
A. CN 3
CN ___ innervates the superior oblique while CN ____ innervates the lateral rectus
A. CN 4; CN 6
B. CN 6; CN 4
C. CN 2; CN 6
A. CN 4; CN 6
True or False: CN 3 adducts and abduccts
True
True or False: CN IV is important for intorsion of superior oblique while CN III is important for extorsion of inferior oblique
True
Where are the oculomotor nerve and the Edinger-Westphal nucleus located?
A. medulla
B. midbrain
C. pons
B. midbrain
Which CN mediates conscious eye
movements and reflexes?
Oculomotor nerve
Which 2 structures are innervated by the oculomotor nerve??
extraocular muscles &
levator palpebrae superioris
Which two structures does the Edinger-Westphal nucleus innervate?
pupillary sphincter &
ciliary muscle
What are the effects of a lesion on the oculomotor nerve or the Edinger-Westphal nucleus?
1) Ipsilateral ptosis
2) mydriasis
3) lateral strabismus
Which CN causes depression &
intorsion of the eye + has a nucleus located in the midbrain?
Trochlear nerve
Which CN is the smallest and only one nerve to exit via: dorsal surface?
Trochlear Nerve
Which cranial nerve innervates contralateral superior oblique muscle?
A. Trochlear Nerve
B. Abducens Nerve
C. Oculomotor Nerve
D. Trigeminal Nerve
A. Trochlear Nerve
Which CN mediates lateral
eye movements?
A. Trochlear Nerve
B. Abducens Nerve
C. Oculomotor Nerve
D. Trigeminal Nerve
B. Abducens Nerve
Which CN has a nucleus that is located in the pons and innervates lateral rectus muscle?
A. Trochlear Nerve
B. Abducens Nerve
C. Oculomotor Nerve
D. Trigeminal Nerve
B. Abducens Nerve
True or False: CN III controls medial
rectus of other eye
simultaneously
True
Lesion of which CN results in diplopia?
Abducens nerve
Damaged left abducens nerve results in ___ strabismus and impaired ___ gaze to side of lesion
medial; lateral
Which CN mediates head
turning?
Spinal Accessory
The Spinal Accessory is located in an unusual location – namely: in the …
upper cervical spinal cord
Which CN innervates
sternocleidomastoid to turn
head to opposite side + trapezius to
elevate shoulder?
Spinal accessory
Which CN mediates
movement of the tongue and has its nucleus in the medulla?
Hypoglossal nerve
Which two structures does the hypoglossal nerve innervate?
Intrinsic & extrinsic tongue muscles
Lesion of which CN nuclei results in deviation of tongue towards damaged side?
Damage to hypoglossal nerve
Which CN mediates facial
sensation and chewing?
Trigeminal
Mesencephalic, chief & spinal
trigeminal nuclei are located
throughout brainstem and
upper SC. What are their function?
Touch, pain, temperature sensation
& proprioception for face
The trigeminal motor nucleus in
___and innervates mastication
muscles in ____
pons; (V3) mandibular division
Lesions in which CN nuclei would result in a pronounced jaw-jerk reflex?
CN V
Which CN allows one to express,
taste, cry & salivate?
Facial nerve
True or False: Both the facial nucleus and the superior salivatory nucleus are located in the pons
True
Which of the following innervates muscles of facial expression?
A. Facial nucleus
B. Superior salivatory nucleus
A. Facial nucleus
Which of the following provides parasympathetic innervation to
lacrimal and salivary (sublingual &
submandibular) glands?
A. Facial nucleus
B. Superior salivatory nucleus
B. Superior salivatory nucleus
True or False: Aberrant regeneration of the salivary
fibers that innervate the lacrimal
glands can lead to “crocodile tears”
True
Where are the Inferior Salivatory + Nucleus Ambiguus located?
Medulla
Which CN functions
in swallowing & salivation + provides sensation to posterior 1/3 of the tongue?
Glossopharyngeal nerve
Nucleus ambiguus innervates the ____ while the Inferior Salivatory innervates the ____
stylopharyngeous muscle; Parasympathetic innervation of parotid
gland
Check integrity of ____ nerve with cotton swab to test pharyngeal (gag) reflex
Glossopharyngeal
____ is cranial nerve that is the major
parasympathetic line + provides sensory info from all viscera?
Vagus nerve
Nucleus ambiguus (medulla) and Dorsal Motor Nucleus (medulla) are associated with which CN? Innervation?
Vagus
Nucleus ambiguus: Innervates pharyngeal & laryngeal mu
Dorsal Motor Nucleus: smooth muscles & glands of abdominal/thoracic cavities
Unilateral lesion of vagus produces
____ ____of soft palate and uvula deviation to intact side
ipsilateral plegia
