How many Cranial Nerves (CN) are there?
Are most CN attached via two roots?
For the most part, no. In contrast the spinal nerves are typically attached by two roots.
What is the origin of most CN?
Single attachment from Brainstem or Forebrain
Which two CN are attached by two roots?
V and VII
T or F: Cranial Nerves contain ganglia
True, they contain motor and sensory ganglia
Do all CN contain the same types of fibers?
No, they each contain a different set (GSA, GSE, GVE,GVA, SA, etc.)
Do all spinal nerves contain the same types of fibers?
Yes, they are mixed fiber nerves.
How are cranial components of the parasympathetic system distributed?
Via CN III, VII, IX, X “The parasympathetic club of cranial nerves”
Motor Ganglia are all _______________.
Chain, Collateral, or terminal parasympathetic autonomic ganglia, in cranial nerves they are all terminal ganglia since all motor autonomics are parasympathetic
What are the four parasympathetic ganglia of the CN system?
Cilary, Submandibular, Pterygopalatine, Otic
What CN is associated with the Ciliary ganglia?
What CN is associated with the Submandibular Ganglion?
What CN is associated with the Pterygopalatine ganglion?
What CN is associated with the Otic ganglion?
What type of fibers live in the previously described ganglia?
Postganglionic Parasympathetic fibers
What cell types does a dorsal root ganglion house (recall from last block)?
What CN have associated sensory ganglia?
V, VII, IX, X
What sensory ganglia is associated with V? VII? IX? X?
V:Trigeminal ganglion, VII: Geniculate ganglion, IX: Superior and Inf. ganglia, X: Superior and inf. ganglia
What four functions do CN and spinal nerves share?
GSE, GVE, GVA, GSA
Are special sensory functions unique to cranial nerves?
Yes- Cranial Nerves only (four basic senses)
What functions does GSA have?
General somatic afferent, sensory from skin, skeletal muscles, fascia, joint capsules, ligaments, tendons, aponeuroses, periosteum,
What functions does GVA have?
Sensory from visceral structures: smooth muscle, cardiac muscle, glands
What functions does GVE have?
Parasympathetic motor innervations to smooth muscle, and glands [III,VII,IX,X]
What functions does GSE have?
Motor to skeletal muscle, in head derived from somite or mesoderm
What functions does BE have?
Motor to skeletal muscles in head and neck derived from branchial (pharyngeal) arch mesoderm
What fibers provide sensory information from ectodermally derived structures?
What fibers provide sensory information from endodermally derived structures?
What functions do Special sensory fibers have?
Sensory related to vision, vestibular, and auditory senses, sensory from specialized receptors located in the head which are associated with visceral activity, taste and smell
What provides sensory information from the mucosal lining of oral and nasal cavities?
What provides sensory information from the mucosal lining of pharynx, esophagus, larynx, trachea, middle ear?
What nerve innervates structures derived from the 1st branchial arch? 2nd? 3rd? 4th/6th? 5th?
Mandibular (V3), Facial (VII), Glossopharyngeal (IX), Vagus (X), nothing (arch degenerates), respectively
What nerve allegedly can be associated with the 6th arch and what does it innervate?
XI : SCM, Trapezius
What does the first arch contain?
Muscles of Mastication, Ant. Belly of digastric, Mylohyoid m. , tensor veli palatini m., tensor tympani m.
What does the second arch contain?
Muscles of facial expression, Post. belly of digasatric, Stylohyoid m., stapedius m.
What does the third arch contain?
What does the fourth arch contain?
Larynx, Soft Palate, Pharynx
What does the sixth arch contain?
In a neurological exam if you were testing movements of the uvula what nerve would you be examining?
Vagus (Inn. of soft palate via muscles of 4th branchial arch)
Do nerves develop from these arches?
No, they develop from neural crest cells and grow into the arches.
Are tongue muscles and optic muscles developed from branchiomeric mesoderm?
What provides sensory innervation to the tongue?
No, they develop from somite mesoderm
Facial Nerve (CN7) provides SVA to the anterior two thirds of the tongue
Where are the cell bodies of preganglionic parasympathetic fibers in the head?
What are the targets parasympathetic fibers in the head?
Smooth Muscle and Glans
What does the parasympathetic aspect of VII and IX innervate in the head?
Glands via Submandibular, pterygopalatine, otic ganglia
What does the parasympathetic aspect of III innervate in the head?
Constrictor pupillae muscle via ciliary ganglion
What two CN are responsible for spitting and crying (salivation/tearing)?
What are the targets of sympathetic innervation to the head?
Sweat glands, Dilator pupillae m. , superior tarsal m. (elevates eyelid, nonvoluntarily)
Describe Honer’s syndrome.
Sympathetic lesion to head which causes loss of sympathetic innervation to head, lose sweating, eye is drooping, pupil will not dilate
How do pre-ganglionic sympathetic fibers reach the head?
Ascend from T1/T2 to superior cervical ganglion
How do postganglionic sympathetic fibers reach the head?
Travel perivascularly on carotid arterial system (in contrast to parasympathetics which travel along cranial nerves)
Anytime there is a vascular lesion in the head there is risk of _____________.
Lesions to postganglionic sympathetic fibers
Is your President Black?
Is Your Lambo Blue?
That would be affirmative
Who is the biggest badass ever?
Ya I said it
Foramina of the Cribiform Plate
Superior Orbital Fissure
CN3 - Occulomotor
CN V1 - Opthalmic Nerve