Peripheral Nervous System Flashcards
What are the three sensory nerves?
Olfactory (CN I)
Optic (CN II)
Auditory or Vestibulocochlear (CN VIII)
Cranial nerves with both sensory and motor functions
CN V, CN VII, CN IX, CN X
Trigeminal, Facial, Glossopharyngeal, Vagus, respectively.
Give the 12 cranial nerves.
Olfactory
Optic
Oculomotor
Trochlear
Trigeminal
Abducens
Facial
Auditory
Glossopharyngeal
Vagus
Accessory
Hypoglossal
cranial nerve innervates first pharyngeal arch (muscles of mastication)
trigeminal (CN V)
innervates second pharyngeal arch (muscles of the facial expression)
facial (CN VII)
What are the three meningeal layers?
dura mater, arachnoid, pia mater
innervates third pharyngeal muscles
glossopharyngeal or CN IX
innervates 4 and 6 pharyngeal arches (muscles of pharynx, larynx and esophagus)
vagus or CN X
peripheral nervous system is derived from?
neural crest cells
form satellite cells of the nerve cell bodies w/in
ganglia
amphicytes
connective tissue cells of the PNS are called?
neurolemmocytes
has two (2) processes, 1 axon and 1 dendrite
bipolar neuron
has three (3) or more processes: one (1) axon and 2 or more dendrites
multipolar neuron
has two (2) processes that arise separately from the cell body, fuse for a while to form 1 process and divide shortly thereafter into axon and dendrite
pseudounipolar neuron
has only one process, the axon
unipolar neuron
conduct impulses from the receptor organs to
the CNS (ex. touching a hot surface, these neurons present in your skin will send signals to the nervous system about the information)
sensory or afferent neurons
conduct impulses from the CNS to target organs (ex. snapping your finger)
motor or efferent neurons
transfer sensory impulses from
sensory neurons to efferent neurons
Association neurons or interneurons
innervate voluntary muscles and structures w/ epithelia derived from ectoderm like skin
somatic neurons
innervate involuntary muscles and structures derived from splanchnopleure like blood vessels and visceral organs
visceral neurons
located entirely in the PNS
postganglionic neuron
w/ a cell body in the CNS (nucleus)
the axon extends into the PNS
preganglionic neuron
an axon of neuron and its sheath that connects peripheral structures w/ the brain or spinal cord
nerve fiber
are myelinated nerves segmentally arranged along the spinal cord
spinal nerve
cell bodies of the nerves are either BURIED in the CNS to form ________; or MASSED at some point along the nerve to form _______
nuclei, ganglia
Majority of the nerves in the PNS end and begin in the spinal cord and are therefore called
spinal nerves
At what hour of incubation, does the establishment of spinal nerve root begin? The adult spinal nerve connects w/ the spinal cord by two (2) roots: dorsal root and ventral root.
96 hours
The ________ is the pathway for sensory (afferent) nerve fibers and the ______ for motor (efferent) nerve fibers.
dorsal root, ventral root
The neural crests at the level of the spinal cord become the?
spinal ganglia or dorsal root ganglia
Spinal ganglia are located on the dorsal roots between the spinal cord and the point of union of ventral and dorsal roots. Distal to the union is a branch, ________, which extends ventrad to the sympathetic ganglion.
ramus communicans
conduct impulses from afferent nerve
endings for touch, pain and temperature in the skin to the spinal cord
Exteroceptive GSA spinal nerves
conduct impulses for positional sense from joints, tendons and muscles to the spinal cord
Proprioceptive GSA spinal nerves
Arise from olfactory hair cells and terminate in the rhinencephalon
Olfactory Nerve (CN I)
Arise from sensory neurons in RETINA and terminate in the superior colliculus of
corpora quadrigemina in the brainstem
Optic nerve (CN II)
Arise from the basal plate of mesencephalon and terminate in the inferior oblique and the superior, inferior and internal rectus muscles of the eyeball
Oculomotor (CN III)
Arise from the basal plate of mesencephalon and terminate in the superior oblique muscle of the eye
trochlear nerve
Three main divisions that arise from the semilunar ganglion:
a. Opthalmic, b. Maxillary, and c. Mandibular divisions
Arise from the basal plate of myelencephalon and terminate in the external rectus
muscle of the eyeball. When it contracts it rotates the eyeball outward (abduction)
abducens
arise from the taste buds and terminate in the brain
sensory fibers of facial nerve (CN VII)
gives off short afferent nerve fibers that supply the semicircular canal, utricule and saccule and receive stimuli for the sense of equilibrium (balance)
vestibular ganglion (Auditory/CN VIII)
extend to the skeletal muscles of pharynx and larynx and the smooth muscles of visceral organs
motor fibers of vagus nerve
arise from the posterior myelencephalon and the first 5 or 6 segments of spinal cord and extend to the smooth muscles of the viscera
motor fibers of accessory nerve
supply the skeletal muscles of tongue
hypoglossal nerve (CN XII)
carry impulses from the eye and ear (involved in the relationship of the animal to external environment) to the alar plate of the brain
special somatic afferent
conduct impulses from the basal plate of the brain to skeletal muscles w/ visceral functions
Special Visceral Efferent (SVE)
carry impulses from the chemoreceptors in the olfactory epithelium and taste buds to the alar plate of brain
Special Visceral Afferent (SVA)
