Sensory Pathway Flashcards
____ mediates the pain fibers from pelvis and spinal cord in a patient with gonorrhea
Substance P
The neurotransmitters in the endogenous analgesia system
serotonin, epinephrine, NE
According to Ganong, these are the chemicals and NTs involved in pain modulation
- Serotonin - nucleus raphe magnum and spinal dorsal horn
- NE - Locus Ceruleus
- Morphine - Periaqueductal gray matter
- Enkephalin - Spinal Dorsal Horn
- Opioids - DRG
Tactile receptors that are useful in 2 point discrimination
Merkel and Meissner
___ pathway for touch sensation that require high degree of localization and fine gradation of intensity
Dorsal Column-Medial Lemniscus Pathway;
Spinothalamic Tract is for pain, temp, light touch, pressure, tickle
Type ___ receptive field is smaller with well-defined borders, useful for 2-point discrimination
Type 1
Type 2 Receptive Field is wider but poorly-defined borders.
Remember: pointer finger pointing to something specific for type 1; while raising the middle finger for type 2
This tactile receptor is used for heavy and sustain/steady pressure and to signal degree of joint rotation
Ruffini Corpuscles
These fibers are found in both hairy and glaborous skin and deep tissues with a warmth threshold of 30degC and cold threshold of 24degC.
Type Adelta, Type C
Note: Cold receptors are inactive at <10degC
____ converts environmental signals into neural signals
sensory receptors
[type of sensory receptors]
unmyelinated, innervated by type A delta fibers and type C fibers
nocicepter
[type of sensory receptors]
unmyelinated/lightly myelinated
innervated by typeA delta and Type C fibers
thermoreceptor
the warmth threshold of the thermoreceptor is ____
30 degC
the cold threshold of the thermoreceptor is ___
24 degC
the cold receptors are inactive at
<10 deg C
____ are examples of electromagnetic receptor
rods and cones
depolarization in sensory receptor causes ____
receptor potential/generator potential
[sensory receptor]
detects steady stimulus
slowly-adapting receptors (tonic receptors)
[sensory receptor]
detects onset and offset stimulus, has a predictive function
rapidly-adapting receptors (phasic receptors)
[receptive field]
smaller with well-defined borders
type 1
[receptive field]
wider but with poorly-defined borders
type 2
____ are skin regions controlled by each sensory neuron
receptive field
[type of nerve fiber]
widest, most myelinated, fastest, accurate, precise, needs most energy
type A
[type of nerve fiber]
unmyelinated, thinnest, less precise, less accurate
type C
[type of nerve fiber: specific]
for proprioception, seen in muscle spindle afferents
A-alpha
Ia
[type of nerve fiber: specific]
for proprioception, seen in golgi tendon organs
A-alpha
Ib
[type of nerve fiber: specific]
for touch, pressure seen in secondary afferents of muscle spindles
A-beta
II
[type of nerve fiber: specific]
seen in intrafusal muscle fibers
A-gamma
[type of nerve fiber: specific]
fast pain, temperature
A-delta
[type of nerve fiber: specific]
seen in preganglionic autonomic fibers
B
[type of nerve fiber: specific]
slow pain
C
IV
[type of nerve fiber: specific]
seen in postganglionic autonomic fibers
C
IV
[type of nerve fiber: specific]
acute, electric pain
A-delta
[type of nerve fiber: specific]
burning, aching, tickle, itch
C
IV
[which is more susceptible to…]
hypoxia
B
B>A>C
[which is more susceptible to…]
pressure
A
A>B>C
[which is more susceptible to…]
local anesthetics
C
C>B>A
[sensory receptor]
First-order neuron
dorsal root or cranial nerve ganglia
[sensory receptor]
second order neurons
spinal cord or brainstem
axons may decussate
[sensory receptor]
third-order neuron
relay nucleus of the thalamus
[sensory receptor]
Fourth-order neuron
sensory cortex
[somatosensory pathway]
for position sense and fine pressure
dorsal column
medial lemniscus pathway
[somatosensory pathway]
the decussation of the pathway for position sense and fine pressure is ___
near the medulla
[somatosensory pathway]
the nerve fibers of the dorsal column-medial lemniscus pathway is ___
Type III
large myelinated
[somatosensory pathway]
this pathway is active in two-point discrimination
dorsal column-medial lemniscus pathway
[somatosensory pathway]
this pathway uses smaller myelinated fibers (Type III, IV)
spinothalamic tract
[somatosensory pathway]
the pathway for pain, temperature and light touch decussates at ___
immediately
[somatosensory pathway]
this pathway is for the pain, temperature, light tough, tickle and itch
anterolateral
spinothalamic
[tactile receptor]
used in MOVING 2-point discrimination
meissner corpuscle
[tactile receptor]
fast adapting, receptive field 1
meissner
[tactile receptor]
used in steady 2-point discrimination
merkel disk
slow adapting, receptive field 1
merkel disk
[tactile receptor]
used in 2-point discrimination
merkel (steady)
meissner (moving)
[tactile receptor]
used to determine texture
merkel (steady)
meissner (moving)
[tactile receptor]
slow acting, type 2
ruffini corpuscles
[tactile receptor]
used for sustained steady pressure
ruffini corpuscles
[tactile receptor]
signals degree of rotation
ruffini corpuscles
[tactile receptor]
seen in enlarged dendritic endings with elongated capsules in deep skin
ruffini corpuscles
[tactile receptor]
unmyelinated, onion-shaped
subcutaneous skin and deep fascia
pacinian corpucles
[tactile receptor]
fast acting
type 2
pacinian corpuscles
[tactile receptor]
used in deep pressure
pacinian corpuscles
[tactile receptor]
used in high-frequency (fast) vibration
pacinian corpuscles
[tactile receptor]
active during tapping motion
pacinian corpuscles
speed of fast pain
0.1 sec
[types of pain]
uses Type A-delta fibers or Type III
fast pain
[types of pain]
the neurotransmitter is glutamate
fast pain
[types of pain]
associated with tissue destruction, visceral pain
slow pain
[types of pain]
uses type C fibers or type IV if visceral pain, 1 sec of stimulus
slow pain
[types of pain]
neurotransmitter is Substance P
slow pain
[types of pain]
free nerve endings are triggered at this temp range
<15
or >43
these are considered endogenous analgesia system
serotonin
Epi
NE
[chemical NTs involved in pain modulation]
nucleus raphe magnum and spinal dorsal horn
serotonin
[chemical NTs involved in pain modulation]
locus ceruleus
NE
[chemical NTs involved in pain modulation]
periaqueductal gray matter
morphine
[chemical NTs involved in pain modulation]
spinal dorsal horn
enkephalin
[chemical NTs involved in pain modulation]
dorsal root ganglion
opioids