00 Review of PNS Flashcards
GSE
general somatic efferent - somatic motor
SVE
special visceral efferent - branchiomotor
GVE
general visceral efferent - visceral motor
GSA
general somatic afferent - somatic sensory
GVA
general visceral afferent - visceral sensory
SVA
special visceral afferent - chemiccal sensory
SSA
special somatic afferent - special sensory
what does the general somatic efferent innervate?
voluntary muscles derived from myotomes. includes:
- all striated skeletal muscle supplied by spinal nerves
- muscles that move the eyes
- muscles that move the tongue
what does the special visceral efferent innervate?
voluntary motor innervates muscles derived from embryonic branchial (gill) arches in the head
what cranial nerves exclusively carry special visceral efferents?
V3, VII, IX, X and XI
what do general visceral efferents refer to?
preganglionic sympathetic and parasympathetic fibers
what visceral structures do postganglionic ganglia in the periphery innervate?
smooth muscle, glands, and visceromotor organs (basically any effector that is not voluntary skeletal or branchial muscle)
what spinal nerves carry preganglionic sympathetic fibers
T1 - L2
what spinal nerves and cranial nerves carry preganglionic parasympathetic fibers
spinal nerves S2 - S4
cranial nerves III, VII, IX, and X
what do general somatic afferents carry?
sensory signals from the body wall (skin, muscles, joints) with information about:
- concerning pain
- fine touch
- temperature
- proprioceptive signalling
what type of neurons are general somatic afferents?
pseudounipolar
where do general somatic afferents reside?
those that are associated with a spinal nerve reside in the dorsal root ganglion
those that are part of the cranial system reside in the cranial nerve sensory ganglion
can you consciously experience signals from general somatic afferents?
yes but certain cerebellar proprioceptive signals are “nonconscious”
what type of neurons are general visceral afferents
psudounipolar
where do general visceral afferents reside
dorsal root ganglia or cranial nerve sensory ganglia
what do general visceral afferents carry?
generally, carry nonconscious signals from sensors in the viscera
types of visceral pain that can be experienced consciously
inflammation, distension, sustained smooth muscle cramping, and ischemia
what do special visceral afferents carry?
signals originating from chemical sense of smell and taste
what do special somatic afferents carry?
signals originating in specialized somatic sensors, either in retinal photoreceptors or inner ear hair cells
CN I
olfactory nerve
CN II
optic nerve
CN III
oculomotor nerve
CN IV
trochlear nerve
CN V
trigeminal nerve
CN VI
abducens nerve
CN VII
facial nerve
CN VIII
vestibulocochlear nerve
CN IX
glossopharyngeal nerve
CN X
vagus nerve
CN XI
accessory nerve
CN XII
hypoglossal nerve
what does the olfactory nerve do and what cranial nerve is it?
CN I
- carries SVA (special visceral afferent) olfactory sense from ganglion cells in the olfactory epithelium of the nasal cavity
- central axons project through the cribriform plate of the ethmoid bone to relay in the olfactory bulb
(from olfactory ganglion to olfactory bulb)
what does the optic nerve carry? what cranial nerve is it?
CN II
- carries SSA (special somatic afferent) visual fibers from bipolar ganglion cells in the back of the retina
what 2 fibers does the oculomotor nerve carry?
- GSE (general somatic efferents)
- GVE (general visceral efferents)
where does the oculomotor nerve carry GSE fibers to? CN?
to extraocular muscles:
- superior rectus
- inferior rectus
- medial rectus
- inferior oblique
to the muscles that elevate the upper eyelid:
- levator palpebrae superiors
CN III
where does the oculomotor nerve carry GVE fibers to? CN?
- ciliary ganglion - controls the ciliaris muscle for lense accommodation
- constrictor pupillae muscle - for pupillary constriction
CN III
what does the trochlear nerve carry? CN?
CN IV (4)
carries GSE (general sensory efferents) to the superior olique which is a extraocular muscle that uses the trochlea as a pulley
fibers carried by the trigeminal nerve
SVE (special visceral efferent) and GSA (general sensory afferent)
where does the trigeminal nerve carry GSA fibers to and from? CN?
CN V (5)
carries general sensory afferernt fibers from the face, nasal cavity, nasopharynx, oral cavity, and anterior 2/3 of the tongue (tongue comes from the lingual nerve)
what is the main cranial nerve for somatic sensation from the head?
CN V trigeminal nerve
types of ganglion cells involved in cranial nerve 5 and their location
trigeminal and semilunar
located in the trigeminal cave (a pocket in the dura) that forms as part of an evagination of the tentorium cerebelli near the apex of the petrous part of the temporal bone
what cranial nerve supplied hard tissues like teeth and periosteum of cranial bones
trigeminal nerve (CN 5)
what is CN V3 and what does it carry
the mandibular division of the trigeminal nerve that carries SVE fibers
where does the trigeminal nerve carry SVE fibers to? CN?
8 muscles total:
- 4 muscles of the mastication
- 2 muscles of the oral diaphragm
- 2 small “tensor” muscles = tensor veli palatini and tensor tympani
tensor veli palatini = tightens the soft palate
tensor tympani = dampens oscillations of the malleus in the middle ear ossicle
CN V (5)
what type of fibers does the abducens nerve carry and where? CN?
carries GSE (general sensory effectors) to the lateral rectus which is an extraocular muscle that abducts the eye
CN VI (6)
what types of fibers does the facial nerve carry? CN?
- SVE
- GVE
- SVA
- GSA
CN VII (7)
where does the facial nerve carry SVE fibers to? CN?
to the stapedius (small middle ear muscle) and the muscles of facial expression
CN VII (7)
where does the facial nerve carry GVE fibers to? CN?
- the submandibular ganglion in the oral cavity (controls the submandibular and sublingual salivary glands)
- the pterygopalatine ganglion for control of nasal mucosa and lacrimation
“in short, GVE fibers keep the face wet”
CN VII (7)
where does the facial nerve carry SVA fibers from and to? CN?
from the anterior 2/3 of the tongue (via the chorda tympani branch which travels with the lingual nerve branch of CN V3 for a while) and the palate
to the cell bodies located in the geniculate ganglion within the facial canal of the petrous temporal bone
CN VII (7)
where does the facial nerve carry GSA fibers from and to? CN?
from the small area of the external ear canal and to the cell bodies in the geniculate ganglion
CN VII (7)
what type of fibers does the vestibulocochlear nerve carry and where from? CN?
carries SSA (special somatic afferent)
from the spiral ganglion and the vestibular gangion in the inner ear
these ganglion deal with special senses of hearing and head position sense for balance and various reflexes
CN VIII (8)
what types of fibers does the glossopharyngeal nerve carry? CN?
GSA
SVA
GVA
SVE
GVE
CN IX (9)
where does the glossopharyngeal nerve carry GSA from? CN?
carries GSA fibers from the posterior 1/3 of the tongue, tympanic membrane, and oropharynx (back of the throat)
where does the glossopharyngeal nerve carry SVA from? CN?
carries SVA fibers from the posterior 1/3 of the tongue
where does the glossopharyngeal nerve carry GVA from? CN?
carries GVA fibers from the carotid body (senses pO2/pCO2 in the blood of carotid arteries) and carotid sinus (blood pressure)
where do the GSA, SVA, and GVA fibers of the glossopharyngeal nerve (IX) go to?
to the sensory gangion located on the IX nerve just outside the jugular foramen of the skull
where does the glossopharyngeal nerve carry SVE to and what does it do?
carries to the stylopharyngeus muscle which elevates the pharynx during swallowing
where does the glossopharyngeal nerve carry GVE fibers to and what does it do?
carries to the otic ganglion for control of the parotid salivary gland
what fibers does the Vagus nerve carry? CN?
- GSA
- SVA
- GVA
- SVE
- GVE
where does vagus nerve carry GSA fibers from?
from the nasopharynx (lowest part of the throat), larynx, upper esophagus, and external acoustic meatus
where does vagus nerve carry SVA from?
carries SVA taste fibers from the the epiglottis (minor function)
where does vagus nerve carry GVA fibers from?
carries from basically the entire body viscera (major function of vagus nerve)
where does vagus nerve carry SVE fibers to?
to all of the muscles in the larynx, pharynx, and palate
larynx (in relation to the vagus nerve)
phonation
pharynx (in relation to the vagus nerve)
swallowing, except styopharyngeus controlled by IX
palate (in relation to the vagus nerve)
control of both levator veli palatini and palatoglossus enables vagus to control palatal position during swallowing and speech.
where does the vagus nerve carry GVE fibers to and from?
to every visceral structure below the head down to the end of the midgut (heart, bronchial smooth muscle, most of the gut tube)
from the postganglionic gangla located in the walls of taret organs or near them
what organs are developmentally lower than the midgut and were do they get their nerves from?
organs: hind gut, pelvic/perineal organs
from the pelvic splanchnic nerves
what fibers does the accessory nerve carry? CN?
carries SVE fivers
CN XI
what do the SVE fibers carried by the accessory nerve do? where are the cell bodies located?
control the trapezius and sternocleidomastoid
cell bodies located in the spinal cord ventral horn (upper cervical segments)
leave the cord but pass directly up between the dosal and cetral rootlets, pass through th eforamen magnum, then leave th eskull via the jugular foramen.
what fibers does the hypoglossal nerve carry? CN? what is the purpose?
carries GSA fibers to muscles that move the tongue and control its shape
CN XII
