LECTURE 7: peripheral nerves Flashcards
are all neural structures in the PNS protected by bone
no
which CNs would be considered part of the CNS
1 & 2 bc they don’t not exit the skull
are anterior and posterior ramus part of the PNS
yes
in the PNS what is the gray matter
ganglia : collections of neuron cell bodies in the pNS
what is the white matter in the PNS
bundles of axons in the PNS
what are the type of neurons in the PNS
afferent
efferent
interneurons
where are the cell bodies from the afferent neurons
dorsal root ganglion outside of sc
where are the afferent neurons going to
skin to the spinal cord
where are the cell bodies for efferent neurons
ventral horn
where is the efferent neurons traveling to
ventral horn to outside of the body
what are clusters of peripheral neuronal cell bodies
ganglia
what are large cable-like tissue grouped by numerous
fascicles
nerve trunk
what are groups of axons bound into bundles
nerve fascicle
what is the Perineurium
wrapping around fascicle
what transports chemicals between axon and cell body and provides information for genetic machinery to regulate cell’s basic function
axoplasm
Axoplasm thickens and becomes more resistant to flow when
stationary
what is the general function of type 1a fibers
muscle spindle primary ending
what is the general function for 1b fiber type
golgi tendon organs
what is the general function for typer II fiber
touch , kinesthesia , muscle spindle secondary ending
what is general function of type III fiber of peripheral axons
pain , crude touch , pressure , temperature
what is the general function of type IV fiber of peripheral axon
pain , touch , pressure , temp
is the sensory division of the PNS afferent or efferent
afferent
what are the 2 sensory division within the sensory division of the PNS
somatic and visceral
what type of motor is somatic motor
voluntary
what type of motor is visceral motor
involuntary motor
visceral motor in the pns is like what other system
automonic nervous system : parasympathetic and sympathetic
the somatic motor division of the PNS innervates what
all skeletal muscle
the somatic sensory system of the PNS is speaical for what
hearing , equilibrium and vision
what visceral sensory system in the PNS is special for what
taste and smell
how many pairs of spinal nerves attach thru ventral and dorsal n roots
31
C1-C7 spinal nerves emerge where
above respective vertebrae
C8 spinal nerve rest and emerge …
below respective vertebrae
if there is an impingement between C6 - C7 disc what would be effected
C7 SN
what typee of information does the ventral roots carry
motor
what type of information foes the dorsal root carry
sensory
where are the cell bodies for afferent nerve
dorsal root
where are the cell bodies for the efferent nerve
ventral root
where do the dorsal and ventral roots join together what what do they form
form the spinal nerve in the intervertebral foramen
what ramus inn postiero vertebra and over lying skin
dorsal
what ramus inn anterior and lateral body and limb of skeleton , mm and skin
anterior
what is the cervical plexus
C1 - C4
what is the brachial plexus
C5 -T1
what is the lumbar plexus
L1 - L 4
can damage to 1 spinal segment or root completely paralyze any limb muscle
no
what does the cervical plexus carry
efferent nn to many mm of neck
afferent nn from skin of skin , shoulder and scalp near ear
what is the sole motor supply of diaphragm
phrenic nerves C3 C4 C5
where does the brachial plexus carry efferent and afferent nerves
efferent : mm of shldr, arm, forearm,
hand
afferent: same skin of same areas
what are the main nerves of the brachial plexus
musculocutaneous
median
ulnar
axillary
radial
where does the lumbar plexus carry efferent nerves to
mm of anterior pelvis , anterior and medial thigh
where does the lumbar plexus carry afferent nerves to
from skin of anterior pelvis , anterior and medial thigh and medial lower leg
where does the sacral plexus originate from
ventral rami of L5 - S5
where does the sacral plexus carry efferent nn to
mm of posterior
pelvis, post thigh, ant and post lower
leg and foot
where does the lumbar plexus carry afferent nn from
skin fo posteior pelvis , post thigh , ant and post lower leg and foot
what is a mononeuropathy and examples
single n involvement
bell’s palsy , carpal tunnel
what is polyneuropathy and examples
distal , symmetric distribution
diabetics
what is multifocal random, asymmetric involvement of individual nn
multiple mononeuropathy
what is repeated mechanical pressures impair blood flow and cause changes to connective tissue of n
traumatic myelinopathy (mononeuropathies)
what is an example of traumatic myelinopathy
carpal tunnel
in traumatic myelinopathy myelin becomes damaged and with sensitization of nociceptors the n becomes excessively
sensitive to ____ or _____ stimul
mechanical or chemical
what is it If Schwann cells and connective tissues intact, can regrow at rate of 1 mm/day
traumatic axonopathy
traumatic axonopathy occurs after
crush injury or closed fx
what is the prognosis for severance
poor
what syndrome is an nflammatory demyelinating syndrome that typically occurs after viral infection causing more motor than sensory problems, distal to proximal
progression
Guillain-Barré Syndrome which is acute inflammatory demyelinating polyraciculoneurppathy
polyneuropathy is a symmetric involvement of what
sensory, motor, and autonomic fibers
polyneuropathy progress from
distal to proximal
what are the first symptoms of polyneuropathy
sensory loss/ dysfunction
small fiber symptoms of polyneuropathy include
pain, temperature, numbness, dysthesias
large fiber symptoms of polyneuropathy is
sensory ataxia, proprioception and
vibration sense
polyneuropathy will present with signs and symptoms of
Lower motor neuron disease (decrease DTR., atrophy , weakness)
if you have a PNS dysfunction what is the muscle tone
hypotonia ( opposite for CNS)
if you have a PNS dysfunction how does your muscle atrophy
fast
in a dysfunction of the PNS DTRs are
decreased or absent
