p.16
Functions of Each Cranial Nerve
How are the upper and lower facial muscles controlled by the brain?
Upper face muscles are controlled bilaterally, while lower facial muscles are controlled contralaterally.
p.23
Oculomotor, Trochlear, and Abducens Nerves
Where does the spinal accessory nerve (CN XI) emerge from?
The lower part of the medulla oblongata.
p.20
Functions of Each Cranial Nerve
What types of sensory impulses does CN IX conduct?
Taste and general sensory impulses from the tongue and pharynx.
Where are motor nuclei located in the brainstem?
In the medial region of the brainstem.
p.16
Functions of Each Cranial Nerve
What type of sensory impulses does the facial nerve convey from the posterior auricular region?
General sensory impulses.
p.16
Functions of Each Cranial Nerve
Which nucleus is responsible for parasympathetic impulses to salivary glands?
Superior salivatory nucleus.
Where are the Alar plates located?
In the dorsal part of the neural tube.
Where are the basal plates located?
In the ventral part of the neural tube.
Where are motor nuclei located in relation to sensory neurons?
In the medial side of the brainstem.
p.23
Cranial Nerve Assessment in Neurological Examination
How can you test the function of the trapezius muscle?
Ask the patient to shrug their shoulders while you press down on them.
p.11
Oculomotor, Trochlear, and Abducens Nerves
What happens to the left eye when the patient tilts her head to the left?
The left eye incyclotorts.
p.7
Olfactory and Optic Nerves
What is the cell of origin for the optic nerve?
Retinal ganglion cells (RGC).
p.6
Cranial Nerve Nuclei Locations
Where do the neurons in the lateral geniculate nucleus (LGN) project the visual signal?
To the primary visual cortex.
p.17
Cranial Nerve Assessment in Neurological Examination
What are the signs of damage to the vestibular system?
Vertigo, dysequilibrium, and nystagmus.
p.15
Functions of Each Cranial Nerve
What is the function of the branchial motor component of the Facial Nerve?
Innervates the muscles of the face for facial expression and mastication.
p.20
Functions of Each Cranial Nerve
What are the motor functions of CN IX?
Innervates part of the tongue and pharynx, and provides motor fibers to the parotid salivary gland.
p.14
Functions of Each Cranial Nerve
What type of nerve is CN V (Trigeminal)?
A mixed nerve with both motor and somatosensation functions.
p.14
Peripheral Distribution of Cranial Nerves
What is the peripheral distribution of CN V?
Three divisions that head to mucus membranes and skin of the face and head.
What reflex is lost with damage to CN V?
Loss of corneal reflex on ipsilateral stimulation.
What happens to neurons throughout neural development?
They proliferate, differentiate, and the brainstem expands.
p.23
Functional Components of Cranial Nerves
What type of function does the spinal accessory nerve serve?
Branchial motor function.
p.9
Oculomotor, Trochlear, and Abducens Nerves
Which cranial nerve innervates all extraocular muscles except the superior oblique and lateral rectus?
Cranial Nerve III (CN III).
p.8
Cranial Nerve Assessment in Neurological Examination
What happens to the pupil in case of damage to the Oculomotor Nerve?
Mydriasis and loss of pupillary light reflex.
p.6
Functions of Each Cranial Nerve
How is the visual field projected on the retina?
In an upside-down and left-right reverted manner.
p.6
Functions of Each Cranial Nerve
Which side of the brain processes the left visual field?
The right side of the brain.
p.17
Functional Components of Cranial Nerves
What is the role of the vestibular ganglion?
Responsible for balance; damage can cause vertigo, dysequilibrium, and nystagmus.
p.17
Functions of Each Cranial Nerve
What is the consequence of a lack of good vision on the vestibular system?
It can lead to a heavy fall if the vestibular system is not functioning normally.
p.15
Functions of Each Cranial Nerve
What does the visceral motor component of the Facial Nerve control?
Nasal and lacrimal secretions.
p.12
Functions of Each Cranial Nerve
What type of nerve is the Abducens Nerve (CN VI)?
A pure motor nerve for somatic motor function.
p.10
Cranial Nerve Nuclei Locations
Where does the Trochlear Nerve emerge from the brain?
At the dorsal side, below the inferior colliculus.
p.10
Cranial Nerve Nuclei Locations
What is the nucleus of the Trochlear Nerve?
Trochlea nucleus (somatic motor).
p.10
Functions of Each Cranial Nerve
What are the primary functions of the Trochlear Nerve?
Intorsion and depression of the adducted eye.
Where do sensory neurons resize in the brainstem?
In the dorsal lateral regions.
p.8
Functional Components of Cranial Nerves
Which muscles are innervated by the somatic motor component of the Oculomotor Nerve?
Superior rectus, medial rectus, inferior rectus, inferior oblique, and levator palpebrae superioris.
p.9
Oculomotor, Trochlear, and Abducens Nerves
What additional function does CN III provide besides eye movement?
It supplies the elevator of the upper eyelid.
p.9
Functions of Each Cranial Nerve
What is the accommodation reflex?
An adaptation of the visual apparatus to facilitate near vision.
p.7
Olfactory and Optic Nerves
What is the pathway of the optic tracts after the optic chiasm?
They continue posteriorly around the midbrain, synapsing in the LGN.
p.7
Functions of Each Cranial Nerve
What occurs when light is shone on one eye?
Both pupils will constrict (direct and consensual pupillary constriction).
p.17
Cranial Nerve Nuclei Locations
What is the function of the vestibular nuclei?
Balancing, coordinating body movements, and eye movements.
p.15
Overview of Cranial Nerves
What are the two roots of the Facial Nerve?
One motor root and a smaller intermediate nerve.
p.19
Functional Components of Cranial Nerves
What are the five functional components of the Glossopharyngeal Nerve?
Branchial motor, visceral motor, special sensory, general sensory, and visceral sensory functions.
p.26
Functions of Each Cranial Nerve
What is the primary function of CN X Vagus?
Branchial Motor and Visceral Motor.
p.2
Functional Components of Cranial Nerves
What does a ventral view of the brainstem show?
The location and functional components of the cranial nerves.
What are the signs of damage to the Abducens Nerve?
Double vision, medial deviations, inability to abduct the affected eye.
p.5
Olfactory and Optic Nerves
What structure do the dendrites of primary olfactory neurons terminate in?
A knob, from which numerous cilia project.
p.5
Olfactory and Optic Nerves
Where does the olfactory bulb sit?
On the cribriform plate of the ethmoid bone.
p.5
Olfactory and Optic Nerves
What do the peripheral processes of receptor cells synapse on?
Secondary sensory neurons in the olfactory bulb.
p.23
Functions of Each Cranial Nerve
Which muscles are innervated by the spinal accessory nerve?
Trapezius and sternocleidomastoid.
p.23
Cranial Nerve Assessment in Neurological Examination
What are the signs of damage to the spinal accessory nerve?
Weakness in turning the head toward the opposite side and shrugging the shoulder.
p.23
Functions of Each Cranial Nerve
What additional muscles does the cranial root of the accessory nerve innervate?
Muscles of the larynx and pharynx.
p.6
Cranial Nerve Nuclei Locations
How do the medial and lateral retinal ganglion cells project to the thalamus?
Medial cells project contralaterally, while lateral cells project ipsilaterally.
p.17
Functions of Each Cranial Nerve
What systems provide information about the body's position in space?
Visual, conscious proprioceptive, and vestibular systems.
p.15
Cranial Nerve Assessment in Neurological Examination
What is a sign of damage to the general sensory component?
Insignificant somatosensation loss.
p.13
Functional Components of Cranial Nerves
What are the three nuclei associated with somatosensation in the Trigeminal Nerve?
Mesencephalic trigeminal nucleus, Pontine/Principal trigeminal nucleus, Spinal trigeminal nucleus.
p.19
Functions of Each Cranial Nerve
What reflexes are associated with the visceral sensory function of CN IX?
Reflexes of the carotid sinus and bulb.
p.1
Overview of Cranial Nerves
What are cranial nerves?
Nerves that emerge directly from the brain and brainstem, primarily distributed in the head and neck region.
p.1
Classification of Cranial Nerves
What types of functions do cranial nerves have?
Some have only sensory functions, some only motor functions, and some are mixtures of both.
p.20
Functions of Each Cranial Nerve
From which part of the tongue does CN IX provide taste sensation?
The posterior 1/3 of the tongue.
p.14
Cranial Nerve Nuclei Locations
What are the central connections of CN V?
Spinal trigeminal nucleus (caudal part) and Principal trigeminal nucleus.
What is a sign of damage to CN V?
Loss of facial sensations.
p.14
Functions of Each Cranial Nerve
What muscles are involved in mastication innervated by CN V?
Temporalis, masseter, lateral and medial pterygoids, tensor veli palatini, tensor tympani, anterior belly of digastric, and mylohyoid.
p.16
Functions of Each Cranial Nerve
What other functions does the facial nerve have besides motor and sensory?
It has branches for somatosensation, taste, and visceral motor functions.
p.11
Oculomotor, Trochlear, and Abducens Nerves
What is the position of the right eye after infarction of CN IV?
The right eye is extorted and slightly elevated, causing double vision.
p.8
Functions of Each Cranial Nerve
What is the function of the visceral motor component of the Oculomotor Nerve?
Pupillary contraction and accommodation of the lens.
p.6
Functions of Each Cranial Nerve
How does light travel through the eye to reach the optic nerve?
Light enters through the lens, is focused, and projects onto the retina, passing through different cell layers to reach the photoreceptor cells.
p.25
Cranial Nerve Nuclei Locations
Through which canal does the Hypoglossal Nerve exit the skull?
Via the hypoglossal canal.
What happens to the tongue in case of peripheral damage to the Hypoglossal Nerve?
It will deviate to the ipsilateral damaged side on protrusion.
p.21
Functions of Each Cranial Nerve
What type of fibers are the motor fibers of the Vagus Nerve?
Parasympathetic fibers to the heart, lungs, and other internal organs.
p.26
Cranial Nerve Nuclei Locations
What nucleus is responsible for the pupillary light reflex?
Edinger-Westphal nucleus.
p.2
Functional Components of Cranial Nerves
What terms do some textbooks use instead of 'sensory' and 'motor' for cranial nerves?
'Afferent' for sensory and 'efferent' for motor.
Where are sensory nuclei located in the brainstem?
In the lateral region of the brainstem.
p.16
Functions of Each Cranial Nerve
From where does the facial nerve convey sensory impulses related to taste?
From taste buds of the anterior 2/3’s of the tongue.
p.16
Functions of Each Cranial Nerve
What are the six major branches of the facial nerve?
Temporal, Zygomatic, Buccal, Mandibular, Cervical, and Posterior auricular.
p.10
Cranial Nerve Assessment in Neurological Examination
What happens to the eyeball if the Trochlear Nerve is damaged?
The eyeball will deviate outward, leading to diplopia (double vision).
p.11
Oculomotor, Trochlear, and Abducens Nerves
What occurs to the eyes when the patient tilts her head to the left after CN IV infarction?
The right eye becomes extorted and the left eye intorted.
p.11
Oculomotor, Trochlear, and Abducens Nerves
What is the role of the superior oblique muscle after CN IV infarction?
It is weak and does not affect the position of the eye.
p.6
Functional Components of Cranial Nerves
What part of the nervous system does the optic nerve belong to?
Central Nervous System (CNS).
p.4
Functional Components of Cranial Nerves
Where are the receptor cells for the Olfactory Nerve located?
In the olfactory epithelium as bipolar cells.
p.25
Cranial Nerve Nuclei Locations
Where do the fibers of the Hypoglossal Nerve arise from?
From the medulla in the medial side, inferior to the pyramid.
p.17
Functional Components of Cranial Nerves
What happens if the spinal ganglion is damaged?
It can cause neural deafness.
p.21
Functions of Each Cranial Nerve
What is unique about the Vagus Nerve compared to other cranial nerves?
It is the only cranial nerve that extends beyond the head and neck region.
p.15
Cranial Nerve Assessment in Neurological Examination
What is a sign of damage to the visceral motor component?
Loss of lacrimation and dry mouth.
p.21
Functions of Each Cranial Nerve
What is the significance of the inferior (nodose) ganglion in the Vagus Nerve?
It is involved in visceral sensory functions, particularly taste.
p.19
Overview of Cranial Nerves
Where does the Glossopharyngeal Nerve (CN IX) emerge from?
The upper part of the medulla.
p.26
Functions of Each Cranial Nerve
What functions are associated with CN IX Glossopharyngeal?
Branchial Motor, Visceral Motor, Visceral Sensory, Special Sensory, Somatic Sensory.
p.26
Cranial Nerve Nuclei Locations
What is the location of the Cochlear nucleus?
Between the pons and medulla.
p.12
Peripheral Distribution
Which muscle does the Abducens Nerve innervate?
The lateral rectus muscle.
p.10
Functional Components of Cranial Nerves
What is unique about the fibers of the Trochlear Nerve?
They cross the midline before exiting the brainstem.
What is the result of damage to the trigeminal motor nucleus?
Deviation of the opened jaw to the ipsilateral side.
p.9
Cranial Nerve Nuclei Locations
What is the role of the Edinger-Westphal nucleus?
It sends axons to innervate cells in the ciliary ganglion, controlling the sphincter of the pupil and the ciliary muscle.
p.7
Olfactory and Optic Nerves
Where does the optic nerve connect centrally?
Lateral geniculate nucleus (LGN) in the thalamus.
p.4
Peripheral Distribution of Cranial Nerves
What is the peripheral distribution of the Olfactory Nerve?
Cilia at the surface of the olfactory epithelium in the superior nasal concha and upper third of the nasal septum.
p.4
Functional Components of Cranial Nerves
What type of cells constitute the Olfactory Nerve?
Bipolar cells in the olfactory epithelium.
p.15
Functions of Each Cranial Nerve
What type of nerve is the Facial Nerve (CN VII)?
It is a mixed nerve with both motor and sensory functions.
p.21
Functions of Each Cranial Nerve
What is the function of the visceral motor fibers of the Vagus Nerve?
Cardiac depression, bronchoconstriction, GI tract peristalsis, and secretion.
p.15
Cranial Nerve Assessment in Neurological Examination
What is a sign of damage to the special sensory component?
Loss of taste in the anterior 2/3 of the tongue, ipsilaterally.
p.13
Trigeminal and Facial Nerves
Where does the Trigeminal Nerve (CN V) emerge from?
The lateral side of the pons as a large bundle.
p.19
Cranial Nerve Assessment in Neurological Examination
What is a sign of damage to the special sensory function of CN IX?
Loss of taste in the posterior 1/3 of the tongue, ipsilaterally.
p.26
Functions of Each Cranial Nerve
What functions does CN V Trigeminal perform?
Branchial Motor and Somatic Sensory.
p.1
Cranial Nerve Assessment in Neurological Examination
Why is the assessment of cranial nerves important?
Abnormalities of function can help pinpoint the site of lesion during neurological examinations.
p.20
Classification of Cranial Nerves
What type of nerve is CN IX?
A mixed nerve with motor and sensory functions.
p.5
Olfactory and Optic Nerves
Where do primary olfactory neurons connect in the olfactory bulb?
With secondary olfactory cells (mitral cell or tuft cell).
p.5
Olfactory and Optic Nerves
How often do bipolar cells in the olfactory epithelium undergo replacement?
Continuously throughout life.
p.5
Olfactory and Optic Nerves
What do the peripheral processes of receptor cells form?
Small bundles that pass through the cribriform plate.
p.10
Cranial Nerve Assessment in Neurological Examination
What signs indicate damage to the Trochlear Nerve?
Diplopia, head tilt to the unaffected side, and weakness in depression of the ipsilateral adducted eye.
p.11
Oculomotor, Trochlear, and Abducens Nerves
Which muscles are activated in the right eye when the patient tilts her head to the left?
The inferior oblique and inferior rectus muscles.
p.23
Cranial Nerve Nuclei Locations
What are the origins of the cranial and spinal roots of the accessory nerve?
Cranial root from the medulla; spinal root from the spinal accessory nucleus in C1-C6.
p.6
Functions of Each Cranial Nerve
What creates electrical impulses in the retina?
Photoreceptor cells (rod and cone cells).
p.7
Functions of Each Cranial Nerve
What happens during the pupillary light reflex?
Constriction of the pupil in response to intense light.
p.25
Functions of Each Cranial Nerve
What type of nerve is the Hypoglossal Nerve (CN XII)?
A pure somatic motor nerve.
p.25
Functional Components of Cranial Nerves
What muscles does the Hypoglossal Nerve innervate?
Intrinsic muscles of the tongue and extrinsic muscles (styloglossus, hyoglossus, genioglossus).
p.17
Functional Components of Cranial Nerves
What is the role of hair cells in the semicircular ducts?
They are involved in balance.
p.15
Cranial Nerve Assessment in Neurological Examination
What is a sign of damage to the branchial motor component of the Facial Nerve?
Paralysis of ipsilateral upper and lower facial muscles.
p.21
Functions of Each Cranial Nerve
What are the peripheral distributions of the Vagus Nerve's visceral sensory function?
Pharynx, larynx, trachea, bronchi, esophagus, stomach, small intestine, ascending and transverse colon.
p.13
Trigeminal and Facial Nerves
What are the three divisions of the Trigeminal Nerve (CN V)?
Ophthalmic division, Maxillary division, Mandibular division.
p.19
Functions of Each Cranial Nerve
What does the special sensory function of CN IX innervate?
The posterior 1/3 of the tongue.
p.26
Cranial Nerve Nuclei Locations
Where is the Hypoglossal nucleus located?
At the level of the medulla on the medial side.
p.12
Functions of Each Cranial Nerve
What is the primary function of the Abducens Nerve?
Abduction of the eye (moving the eyes laterally).
p.16
Functions of Each Cranial Nerve
What is the primary motor function of the facial nerve?
Conveys motor impulses to muscles of the face for facial expressions.
p.16
Functions of Each Cranial Nerve
Why is the control of upper and lower facial muscles important?
It helps differentiate the location of nerve injury.
p.8
Cranial Nerve Nuclei Locations
Where does the Oculomotor Nerve emerge from?
The medial part of the brainstem, at the level of the midbrain, superior to the pons.
p.8
Cranial Nerve Assessment in Neurological Examination
What are the signs of damage to the Oculomotor Nerve?
Ophthalmoplegia with the eye deviated down and out, severe ptosis, mydriasis, and loss of pupillary light reflex.
p.11
Oculomotor, Trochlear, and Abducens Nerves
What is the result when both eyes are aligned after CN IV infarction?
The patient's diplopia resolves.
p.7
Functions of Each Cranial Nerve
What allows for bilateral constriction of pupils?
Projection of some optic nerve fibers bilaterally through the oculomotor nerve.
p.25
Functions of Each Cranial Nerve
What functions does the Hypoglossal Nerve control?
Movement of the tongue, contributing to swallowing and speech.
p.15
Overview of Cranial Nerves
Where does the Facial Nerve emerge from?
The cerebellopontine angle.
p.21
Functions of Each Cranial Nerve
What is the role of the Vagus Nerve in visceral sensory function?
It is involved in visceral sensation, reflexes, and taste functions at the epiglottis.
p.15
Functions of Each Cranial Nerve
What does the general sensory component of the Facial Nerve provide sensation to?
The posterior auricular region and external auditory meatus.
p.19
Cranial Nerve Assessment in Neurological Examination
What is a sign of damage to the general sensory function of CN IX?
Anesthesia of the tonsillar region and loss of gag reflex.
p.1
Functional Components of Cranial Nerves
What should one understand about cranial nerves?
The classifications, major functions, origin, and operation of each cranial nerve.
p.8
Functional Components of Cranial Nerves
What is the role of the Edinger-Westphal nucleus in relation to the Oculomotor Nerve?
It is involved in the pupillary light reflex and controls the contraction of the pupil and accommodation of the lens.
p.9
Functions of Each Cranial Nerve
What are the components of the accommodation reflex?
Increase in lens curvature, pupillary constriction, and convergence of the eyes.
p.6
Cranial Nerve Assessment in Neurological Examination
What happens to the pupillary light reflex in a blind eye?
There is a bilateral absence of the pupillary light reflex on testing the blind eye.
p.17
Functions of Each Cranial Nerve
What are the two main functions of the Vestibulocochlear Nerve (CN VIII)?
Vestibular functions (balancing) and cochlear functions (hearing).
What are the signs of damage to the Hypoglossal Nerve?
Wasting of ipsilateral tongue muscles and deviation to the ipsilateral side on protrusion.
p.21
Functions of Each Cranial Nerve
What are the signs of damage to the branchial motor function of the Vagus Nerve?
Dysphagia, hoarseness, and paralysis of the soft palate with deviation of the velum and uvula to the contralateral side.
p.15
Functions of Each Cranial Nerve
What is the function of the special sensory component of the Facial Nerve?
Responsible for taste in the anterior two-thirds of the tongue.
p.19
Cranial Nerve Nuclei Locations
Where are the cells of origin for the visceral motor function of CN IX located?
In the inferior salivatory nucleus.
p.1
Classification of Cranial Nerves
What is a key difference between cranial nerves and spinal nerves?
Cranial nerves are associated with one or more functions and may overlap in territory, while spinal nerves supply sensory and motor function for specific body segments.
p.1
Overview of Cranial Nerves
What is a mnemonic to remember the 12 cranial nerves?
On Old Olympus’ Towering Top, A Famous Vocal German View Some Hops.
p.21
Functions of Each Cranial Nerve
What is the function of the Vagus Nerve's branchial motor component?
Deglutition and phonation.
p.19
Functions of Each Cranial Nerve
What areas does the general sensory function of CN IX provide somatosensation for?
Epiglottis, soft palate, uvula, tonsil, pharynx, and more.
p.19
Functions of Each Cranial Nerve
What is the function of the branchial motor component of CN IX?
Innervates the stylopharyngeus and superior pharyngeal constrictor to elevate the pharynx.
p.1
Overview of Cranial Nerves
How can cranial nerves be identified?
By a number I to XII or a specific name.
