17 JUNE 2019 Flashcards
horner’s syndrome means what?
that the sympathethic nervous system isn’t working
what are four symptoms of horners syndrome:
eyelid drop
constriction of the pupil
flushing (due to vasodilation)
no sweating
why do the symptoms of horners occur:
sympathetic system causes
- controls the eyelid to widen
- causes pupils to dilate
- causes vessels to constrict
- allows sweat glands to open to cool down body
* **all responses for flight or fight
the sympathetic nervous systems covers what?
the exteremitites
the parasymapthetic nervous systems covers what?
the core / vesseral
orthostatic hypotension occurs when
there is a decrease in BP during 1st 3min of standing
what are the levels of orthostatic hypotension?
20 mm Hg SBP
10 mm Hg DBP
what are tropic changes that happen in the feet with sympathetic nerve damage?
shiny thin fragile hairless skin
redness
lack of sweating
poor nail growth
why do these changes in the feet happen w/ sympathetic damage:
there is no vasoconstriction cutting off blood supply
what does syncope mean?
fainting
a neural reflexive syncope also is called:
vasovagal
when does neural reflexive syncope happen?
in response to stress on the body all your blood vessels open up and then you faint.
orthostatic syncope happens when
blood vessels constrict and close blood flow
cardiac syncope happens when
the heart is unable to pump enough blood
what are the three types of syncope?
neural reflexive
orthostatic
cardiac
how many neuron pathways are there?
3
what are the 3 neuron pathways called?
first order
second order
third order
mechanoreceptors have what subset of receptors:
nocioreceptors
high threshold
chemoreceptors have what type of subset of receptors:
nocioreceptors
high threshold
light cutaneous receptors can feel what?
touch pain and temperature
deep cutaneous receptors can feel what?
propriocpetion nociception (passive)
tonic receptors are
slow adapting
phasic receptors are
fast adapting
what does a high threshold mean?
it takes a BIG stimulus to trigger the neuron
what are the three receptors in the first order neuron pathway?
mechano
chemo
thermo
phasic receptors do what?
respond to change
tonic receptors do what?
remain the signal
two differences between phasic and tonic receptors?
phasic are fast adapating / respond to change
tonic are slow adapting / remain a signal
what are the sizes of the receptive field?
smaller distally
larger proximally
first order neurons are classified how?
by the size of the diameter
so the top = the largest aka the Ia
what is the scheme for classifying first order neurons?
1a 1b 11 111 1V
scheme ii:
a -beta
a -delta
c
what is the “rule” for diameter size for first order neurons:
the “firster” the number/letter the BIGGER the diameter
how does density change in first order neurons throughout the body?
greater density distally
lesser proximally
what is the receptive field?
the peripheral sensory axon and all its terminal branches
what do a - beta neurons supply:
light (disciminative) touch
what is another word for light touch
discriminative
what can light touch dooo?
describe the touch
locate it on the body
what can superficial receptors feel?
touch vibration pressure hair movement stretch
what neurons supply course touch?
A-delta and C
what are the two subsets of course touch?
nociception
temperature
nociception and temperature are supply by what scheme of first order neurons and then have what type of nerves?
- A-delta and C
2. free nerve ends
a plexus can do what two things?
mix or unmix
which way does the plexus work?
unmixes going proximal to distal
mixes going distal to proximal
difference between a dermatome injury and a peripheral nerve injury?
a dermatome injury you can loss all sensation in your hand
a peripheral nerve injury you can loss only part sensation
