Cranial Nerves - Sufaro Flashcards
What are the functional components of cranial nerves? IE:
GSA
GVA
GSE
GVE
SVA
SSA
SVE
•General Somatic Afferent
Convey sensory input from skin, muscle, bone and joints to the CNS
•General visceral Afferent
Convey sensory input from visceral organs to the CNS
•General Somatic Efferent
Convey motor output to skeletal muscles
•General Visceral Efferent
Convey motor output to glands, and smooth muscles
•Special Visceral Afferent
Convey sensory input of a special sense (e.g. taste, olfaction)
• Special Somatic Afferent
Convey sensory input of hearing, balance and vision
Special Visceral Efferent
Convey motor output to a special organ
What are the components of somatic motor (efferent) cranial nerves?
1st order neurons
Cortex to nucleus
Bilateral input except for lower facial nerve and hypoglossal tongue protrusion fibers
2nd order neurons
interneuron
3rd order neurons
Lower motor neurons
What are the components of sensory (afferent) cranial nerves?
1st order neurons
From organs to nucleus (may be different fibers, take “tremps”)
2nd order neurons From nucleus (like NTS) to thalamus
3rd order neurons
Thalamus to cortex
What are the four nuclei of the trigeminal nerve?
- Mesencephalic trigeminal nucleus
Proprioception (runs with motor) - Pontine trigeminal (or nucleus chief sensory nucleus main sensory nucleus or primary nucleus or principle nucleus)
In pontine tegmentum
Tactile input to face - Spinal trigeminal nucleus (medulla, pons, C1-C3)
Pain and temperature - Motor trigeminal nucleus (medially to the other 3 sensory nuclei)
In pontine tegmentum
Innervates muscles of mastication and tensor tympani
What is the corneal reflex and what is its ennervation?
Controlled by afferent limb of CN V-1
- The afferent limb is the
ophthalmic nerve - The efferent limb is the
facial nerve
When something touches the cornea (not conjunctiva) eye reflexively closes.
What are the three sensory components of the intermediate nerve?
- Taste
- salivation
- sensory- auricle and ext. auditory
meatus
What are the three nuclei of the facial nerve?
- Main motor in reticular
formation in pons - (Nervus Intermedius) Parasympathetic:
a. lacrimal. Recieves from
hypothalamus & trigeminal
b. Superior salivatory.
Recieves from hypothalamus - Sensory (Nucleus Solitarius)
Taste and general
Greater petrosal nerve is composed of parasympathetic (lacrimal) fibers and GVA of the palatine and nasal area
Which facial nerve lesion is upper motor neuron? Which is lower?
Supranuclear/ central facial palsy is UMN
Bell’s palsy/Peripheral paralysis is LMN
What are the clinical correlations of lesions of CN VII?
- Loss of the corneal (blink) reflex (efferent limb), which may lead to corneal ulceration
- Loss of taste from the anterior two-thirds of the tongue (check for dryness of mouth ipsilaterally and tumors in the nodes or parotid glands)
- Diminished salivation
- Hyperacusis (increased auditory sensitivity), due to stapedius paralysis
- Loss of tearing
What are the three nuclei of the glossopharyngeal nerve?
- Main Motor
- in reticular formation in
medulla oblongata.
Formed by sup. End of
nucleus ambiguous. - Recives corticonuclear
fibers bilaterally. - Innervates
stylopharengeus muscle - Parasympathetic (inferior salivatory)
- Afferent fibers from
hypothalamus. - Recives corticonuclear
fibers bilaterally and
olfactory input through
reticular formation. (medulla oblongada) - Innervates parotid
gland. - Sensory
carotid sinus, – baro/chemo receptors
Posterior 1/3: taste and GVA
What are the clinical correlations of lesion of glossopharyngeal nerve?
I. Loss of the gag (pharyngeal) reflex
(interruption of afferent limb)
II. Loss of taste from the posterior third of the
tongue
What is Vernet/Jugular Foramen Syndrome
•loss of taste in the posterior third of the
tongue (cranial nerve IX)
•vocal cord paralysis & dysphasia (cranial
nerve X)
•Weakness of the sternocleidornastoid and
trapezius (cranial nerve XI)
Clinical correlations- general
