test 3: CN Flashcards
break down of the PNS
~ 36 nerves: 8 Cervical; 13 Thoracic; 7 Lumbar; 3 Sacral; and ~ 5 Caudal.
a spinal nerve contains what types of fibers
Somatic Afferents (SA)
Visceral Afferents (VA)
Somatic Efferents (SE)
Visceral Efferents (VE).
label
somatic afferent and visceral afferent have their bodies where?
dorsal root ganglion
(pseudo unipolar- This type of neuron contains an axon that has split into two branches; one branch travels to the peripheral nervous system and the other to the central nervous system.)
pseudounipolar
A pseudounipolar neuron is a type of neuron which has one extension from its cell body. This type of neuron contains an axon that has split into two branches; one branch travels to the peripheral nervous system and the other to the central nervous system.
example: SA and VA: cell body in dorsal root ganglion
SE their cell bodies where?
SE: cell body in the spinal cord- one nerve synapses on the skeletal muscle
VE axons have cell bodies where?
two part communication
autonomic: sympathetic or parasympathetic
cell body in spinal cord then can synapse down the communicating ramus in the paravertebral ganglion→ back up and down spinal nerve to smooth muscle of blood vessels or skin
or
down the communicating ramus → splanchnic nerve→ synapse on a prevertebral ganglion → continue to GI
The ___: axons that carry impulses from somatic or visceral structures to the central nervous system (CNS)
‘A’ stands for afferent (sensory
The ____: axons that carry impulses away from the CNS to somatic or visceral structures.
‘E’ stands for efferent (motor)
___ carry motor impulses from the CNS to peripheral motor ganglion that innervates smooth muscle, cardiac muscle, or gland cells.
Visceral efferent fibers (VE)
Special Afferents
Special afferent fibers carry sensation to the brain from special senses found only in the head (olfaction, vision, balance, hearing, taste).
Special efferents
Special efferent fibers (SE) carry motor impulses from the brain to striated muscle (branchiomeric) derived embryonically from the branchial arches (formally gills in aquatic animals). These will be considered as SE fibers along with the other SE fibers innervating non-branchiomeric striated muscles.
Cranial nerves
- Olfactory (CNI)
- Optic (CNII)
- Oculomotor (CNIII)
- Trochlear (CNIV)
- Trigeminal (CNV)
- Abducens (CNVI)
- Facial (CNVII)
- Auditory (Vestibulo-cochlear) (CNVIII)
- Glossopharyngeal (CNIX)
- Vagus (CNX)
- Spinal Accessory (CNXI)
- Hypoglossal (CNXII).
old opium octupus, to touch and feel very gloomy vampire and hybrids
sensory or motor CN
Some Say Marry Money But My Brother Say Bad Business Marry Money.
which cranial nerves have sensory axons and possess sensory ganglia?
V, VII, IX, and X
trigeminal, facial, glossopharyngeal and vagus
(most sensory ganglion you can’t see expect for the distal ganglion of vagus)
which cranial nerves contain special sensory?
1,2,7,8,9,10
what cranial nerve contains special sensory for smell?
1 olfactory
what cranial nerve contains special sensory for taste?
7,9,10
facial, glossopharyngeal and vagus
what cranial nerve contains special sensory for vision
2 -optic nerve
what CN contains special sensory for hearing and balance
CN8, vestibulocochlear
which CN contain VE axons that are part of the parasympathetic division?
3,7,9,10
oculomotor, facial, glossopharyngeal and vagus
VE fibers of the CN 3,7,9, and 10 supply ___
such visceral structures as the: smooth muscles of the Iris and Ciliary Body of the eye and the Salivary and mucous glands.
Sympathetic Division axons from the upper thoracic segments of the spinal cord ascend the sympathetic and vago-sympathetic trunks, synapse on ___ neurons in the ____
postganglionic
Cranial Cervical ganglion.
Postganglionic axons of the Cranial Cervical ganglion then “hitch-a-ride” with the major blood vessels of the head to supply visceral structures of the head: ___
smooth muscles of the Iris (pupillary dilators), sweat glands, salivary glands, arrector pili muscles, and major blood vessels
CN 1
olfactory (sensory only)
special sensory information (Smell) to brain.
B.Sensory receptor cell bodies are located in Olfactory mucosa of ethmoidal labyrinth.
C.Their axons pass through the cribriform plate and connect with neurons in the Olfactory bulb of the brain.
D.Cannot see the olfactory nerve fibers grossly- they are small and unmyelinated.
E.Clinically, the olfactory nerve fibers can be damaged by head trauma leading to Anosmia. However, olfactory nerves can replace themselves.
Sensory receptor cell bodies for the olfactory nerve are located in ___
Olfactory mucosa of ethmoidal labyrinth.
the axons of the olfactory nerve pass through the ___
cribriform plate
CN 2
optic nerve (prechiasmatic optic tract) (sensory)
optic canal
A.special sensory: visual
B.The “optic nerve” originates from retinal ganglion cells, which are derived from the brain’s optic vesicle and not from the neural crest.
C. Can not repair itself
D.The ganglion cell axons in the “optic nerve” are not the axons of the visual sensory receptor neurons. The ganglion cells collect visual information from the rods and cones of the retina via the bipolar cells. The rods and cones which are the visual sensory receptor neurons project their axons to the brain through the Optic canal of the skull.
The ganglion cell axons in the “optic nerve” are not the axons of the visual sensory receptor neurons. The ganglion cells collect visual information from the rods and cones of the retina via the ___. The rods and cones which are the visual sensory receptor neurons project their axons to the brain through the Optic canal of the skull.
bipolar cells
CN 3
oculomotor (motor) orbital fissure
A.Is Motor only: Somatic efferents (SE) and Visceral efferents (VE).
B.SE fibers exit the skull via the Orbital fissure and innervate the following extraocular muscles: dorsal rectus, medial rectus, ventral rectus, and ventral oblique and the levator palpebrae superioris.
D.VE fibers are part of the Cranial subdivision of the Parasympathetic (Craniosacral) Division of the Autonomic Nervous System.
E.The preganglionic VE nerve fibers of the oculomotor nerve synapse on postganglionic neurons in the Ciliary ganglion (a “Head” ganglion), which in turn send their postganglionic axons into the eye to innervate pupillary sphincter muscles of the Iris and Ciliary body muscles.
F.When stimulated the sphincter muscles of the Iris contract and cause pupillary constriction (miosis).
G.The Ciliary body muscles when stimulated cause the lens to become more convex (rounder), shortening the focal length, and accommodating for close-up vision.
H.Sympathetic fibers from the Cranial Cervical ganglion innervate pupillary dilator muscles of the iris and when stimulated dilate the pupil.
parasympathetic will cause the pupil to __
sphincter muscles of the Iris contract and cause pupillary constriction (meiosis).