Lecture 7 Flashcards
How many cranial nerves come from the midbrain?
2
CN 3 and 4
How many cranial nerves come from the pons?
4
CN 5, 6, 7, 8
How many cranial nerves come from the medulla?
4
CN 9, 10, 11, 12
Why are cranial nerve 1 and 2 susceptible to MS disease
They are innervated by oligodendricytes instead of schwann cells due to location (they don’t leave the CNS)
What is the only sensory nerve that reaches the cortex WITHOUT going through the thalamus
olfactory
Where does the optic nerve cross?
The optic chiasm
Note: the optic tract is between the chiasm and the brain
What nerve is responsible for pupil constriction AND orienting head and eyes (Saccadic, reflex neck movement)
Oculomotor CNIII
The olfactory nerve exits from what foramen?
Cribiform plate
The optic nerve exits from what foramen
Optic canal
The occulomotor nerve exits what foramen
superior orbital fissue
The trochlear nerve exits what foramen?
Superior orbital fissure
The opthamalic branch of the trigeminal nerve exits from what foramen
superior oribital fissure
The maxillary branch of the trigeminal nerve exits from what foramen
foramen rotundum
the mandibular branch of the trigeminal nerve exits from what foramen
foramen ovale
The abducens nerve exits from what foramen?
superior orbital fissure
The facial nerve exits from what foramen?
auditory canal (Stylomastiod foramen)
The vestibulocochlear nerve exits from what foramen?
auditory canal (stylomastoid)
Glossopharyngeal nerve exits what foramen?
Jugular foramen
The vagus nerve exits through what foramen?
Jugular foramen
The spinal accessory nerve EXITS through what foramen?
Jugular Foramen
The spinal accessory nerve ENTERS the skull through what foramen?
Foramen magnum
The hypoglossal nerve exits the skull from what foramen?
hypoglossal canal
Damage to the R optic tract after the optic chiasm will cause….
L sided homonymous hemianopsia (Blind in the left visual field of both eyes)
Damage to an optic nerve between the optic chasm and the eyeball will cause…
Ipsilateral blindness (full blindness of the eye on that side in both visual fields)
What nerve innervates the “superior oblique muscle” of the eye
Trochlear nerve
The orbicularis oculi does what action, and what is its innervation?
Closes eyes
-Facial nerve
The consensual blink response is activated by _______ ganglion and sent to the _______ spinal nucleus and passed through interneurons in the reticular formation to both ________ nerves in order to close both eyes
Trigeminal
Trigeminal
Both Facial Nerves
The superior colliculus is for _____ whereas the inferior colliculus is for _____
Vision
Hearing
What is the fluid called inside of the vestibular apparatus?
Endolymph
What is the fluid called that separates the bony structures from the membranous labyrinth of the vestibular system?
Perilymph
Movement of the endolymph inside of the semicircular canals detects…
Rotational acceleration/deceleration
What causes the depolarization of the cochlear nerve endings
Vibration of endolymph is detected by hair cells which depolarize and send signal to cochlear nerve endings to activate them
What cranial nerve controls peristalsis inside the esophagus
vagus nerve
What nerve handles the lips closing when you put food in your mouth?
Facial nerve
What nerve closes the larynx when you swallow?
Vagus
What nerve triggers the swallowing reflex (afferent)?
Glossopharyngeal
Where are the cell bodies of the spinal accessory nerve found?
Ventral horn of C1-C4
What nerve decreases HR, Constricts Bronchi, and increases digestion?
Vagus nerve
What nerve controls the efferent part of the gag reflex?
Vagus
Conductive deafness
Transmission of vibrations prevented in the outer or middle ear
What is Sensorineural deafness?
Damage to receptor cells or the cochlear nerve
True or false: Sensorineural deafness is less common than conductive deafness
True
What is dysarthria?
Poor control of speech muscles
Note: they still understand language
Damage to what nerve can cause dysarthria?
Hypoglossal
True or false: The dorsal root ganglion is a part of the CNS
False, it is part of the PNS
White matter tract vs column
Tract- bundle of axons with common destinaton
Column- Several tracts
Where are the cell bodies of efferent neurons found?
Ventral horn
Where are the cell bodies of afferent neurons found?
Dorsal root ganglion
What is epineurium
Fiberous sheath surrounding entire nerve
What is perineurium
Connective tissue wrapping around fascile of axons
What is endoneurium
connective tissue surrounding axon
