20 - Non-Parasympathetic CNs Flashcards
This CN modality provides special senses derived from ectoderm. Sight, sound, and balance.
Special Somatic Sensory (SSS)
This CN modality provides special senses derived from endoderm. Taste.
Special Visceral Sensory (SVS)
This CN modality contain muscles derived from pharyngeal arches.
Special Visceral Motor (SVM)
This CN modality provides general sensation from the viscera.
General Visceral Sensory (GVS)
This CN modality goes to smooth muscles of the gut tract and is autonomic motor.
General Visceral Motor (GVM)
This CN modality provides general senses from ectoderm (skin).
General Somatic Sensory (GSS)
This CN modality goes to skeletal muscles.
General Somatic Motor (GSM)
Cranial nerves typically have same basic structure as spinal nerves, such as…
Dorsal and ventral root
Dorsal root ganglion
Motor components of cranial nerves begin within the brain within motor nuclei, comparable to spinal cord _______ _______.
Anterior horns
Cell bodies of sensory fibers are located in…
Dorsal root (cranial) ganglia
Most cranial nerves, however, are not typical. Cranial nerves _____ and _____ are sensory tracts/nerves but have no dorsal ganglia or roots. Some cranial nerves are strictly motor and have no dorsal ganglia or roots.
CN I
CN II
______ ______ cranial nerves are actually tracts and have no motor nuclei and no sensory ganglia.
Special sensory
_______ cranial nerves begin in cranial motor nuclei. They have no sensory roots and no sensory root ganglia.
Motor
_______ cranial nerves have both cranial motor nuclei and sensory ganglia. Sensory ganglia are usually given specific names.
Mixed
List all the cranial nerves.
Olfactory (I) Optic (II) Oculomotor (III) Trochlear (IV) Trigeminal (V) Abducens (VI) Facial (VII) Vestibulocochlear (VIII) Glossopharyngeal (IX) Vagus (X) Accessory (XI) Hypoglossal (XII)
What are the non-parasympathetic cranial nerves?
Olfactory (I) Optic (II) Trochlear (IV) Abducens (VI) Vestibulocochlear (VIII) Spinal accessory (XI) Hypoglossal (XII)
The olfactory nerve is made up of many fibers that pass from the upper third of the olfactory (nasal) mucosa. Olfactory receptor cells pass through ______ ______ to the olfactory bulbs.
Cribriform plate
What modality is the olfactory nerve?
SVS
Olfactory epithelium is located in the nasal cavity roof and made up of what type of epithelial cells?
Pseduostratified columnar epithelium without goblet cells
These are stem cells that give rise to immature olfactory cells.
Basal cells with pigment granules
Olfactory cells are _______ neurons, with the apical end projecting into the nasal cavity as a knoblike ending with nonmotile cilia. The cilia possess G-protein-linked ______-specific receptors.
Bipolar
Odor
Olfactory cells are bipolar neurons, with the basal end of the cell extending as an __________ axon, bundled with other similar axons through the ethmoid plate to mitral cells located in the olfactory bulb.
Unmyelinated
Olfactory cells senesce and are replaced from ______ cells.
Basal
This is located in the lamina propria and secrete odorant-binding protein. Odorant-binding protein binds to odorant molecule in nasal cavity.
Olfactory glands of Bowman
Olfactory _______ are slender extension of the forebrain.
Tracts
These are expanded endings of the olfactory tracts that lie on either side of the crista galli within the cribriform fossa. Sites where axons of olfactory neurons synapse with dendrites of mitral cells.
Olfactory bulbs
Axons of _______ cells form the major connecting tracts with the olfactory centers within the brain.
Mitral
What is the function of the olfactory nerve (CN I)?
Smell
This cranial nerve begins in the ganglionic layer of retina (not rods and cones) and exits the orbit through the optic canal.
Optic (CN II)
The optic nerve has 50 percent _________ in the optic chiasma near the pituitary gland and internal carotid.
Decussation
What is the function of the optic nerve?
Sight
What is the modality of the optic nerve?
SSS
This cranial nerve supplies four of the six extrinsic muscles of the eye and has a parasympathetic component.
Oculomotor (CN III)
This cranial nerve enters the orbit through the superior orbital fissure and innervates the superior oblique muscle of the eye.
Trochlear (CN IV)
What is the function of the trochlear nerve?
Eye movement
What is the modality of the trochlear nerve?
GSM
This is the only completely crossed cranial nerve and the only cranial nerve that emerges dorsally.
Trochlear (CN IV)
This cranial nerve enters the orbit through the superior orbital fissure and lies on the medial aspect of the lateral rectus muscle of the eye.
Abducens (CN VI)
What muscle does the abducens nerve innervate?
Lateral rectus muscle of the eye
What is the function of the abducens nerve?
Eye movement
What is the modality of the abducens nerve?
GSM
This cranial nerve leaves the cranial cavity via the internal acoustic meatus accompanied by the facial nerve.
Vestibulocochlear (CN VIII)
What is the modality of the vestibulocochlear nerve?
SSS
This component of the vestibulocochlear nerve contains cell bodies in spiral ganglion of the cochlea and functions in hearing.
Auditory (cochlear) component
This component of the vestibulocochlear nerve contains cell bodies in the vestibular ganglion. From receptors for balance and equilibrium and functions in balance.
Vestibular component
This cranial nerve arises from C1-3(4) lateral rootlets (combination of dorsal and ventral roots of cervical nerves). Single trunk enters cranial cavity through foramen magnum.
Spinal accessory (CN XI)
The spinal accessory nerve temporarily joins the cranial root. Cranial roots leave with _______ nerve, which they are considered part of anyway.
Vagus
The spinal accessory trunk exits the cranial cavity via the…
Jugular foramen
The function of the spinal accessory nerve is to provide motor innervation to the _________ and _________ muscles.
Sternocleidomastoid
Trapezius
What is the modality of the spinal accessory nerve?
SVM
Spinal accessory nerve cranial roots originate from nucleus ambiguus in the medulla. It joins with fibers of the vagus nerve and supplies muscles of the larynx via the ________ _______ nerve.
Recurrent laryngeal
This cranial nerve is from the hypoglossal nucleus in the floor of the fourth ventricle and exits the cranial cavity via the hypoglossal foramen.
Hypoglossal (CN XII)
The hypoglossal nerve descends anteriorly in the neck between the internal _______ and internal _______.
Carotid
Jugular
The hypoglossal nerve in the neck gives rise to superior root of _______ _______ and a nerve to thyrohyoid muscle.
Ansa cervicalis
This cranial nerve supplies the extrinsic and intrinsic muscles of the tongue, including genioglossus, hyoglossus, and styloglossus.
Hypoglossal (CN XII)
What is the modality of the hypoglossal nerve?
GSM
***Study cranial foramina for 5 minutes (Slide 27)
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