Sensory System Flashcards
Normal Pressure Hydrocephalus
- headache
- ataxic gait= difficulty waling/magnetic gain (wobbly)
- dementia=confused thinking/slowness of thought (weird)
- incontinence= loss of bladder control (wet)
Neuromuscular Spindle
- mm stretch and position sense (___)
- -found in ___ ___ mm
- -_-__=very fast conducting
proprioception
all striated mm
a-alpha
Meissner Corpuscle
- ____ touch (2pt)
- -concentrated in ____ ____
- -__-___ fiber= fast conducting
(ex. hand in pocket for quarter not dime)
discriminative
finger tips
a-beta
Pacinian Corpuscle
- detection of _______
- -concentrated in ____ and in _____
- -_-____ fiber= fast conducting
vibration
fingers and palm
a-beta
Merkel Nerve Ending
- ______ touch (2pt)
- -_____ touch detail (edges of object, texture)
- -_-___ fiber= fast conducting
discriminative
fine touch
a-beta
Free Nerve Ending
- sensation of:
- -__
- -__
- -__
pain (glutamate/substance P)
crude touch (cotton ball/feather)
temperature
Local Anesthetic
- must pass through ___,___,___
- block ___ ____ (changes ion balance)
- must block ___ nodes
epineurium, perineurium, endoneurium
sodium influx
3
Local Anesthetic
-binds to receptor site on ion channel on ______ side
-binds more readily to ____ _____
(works faster if neuron is firing off)
intracellular side
active neurons
Nociception vs Pain
–
Types of Pain
- fast pain= irritation from brain
- slow pain= seconds wave (throbbing/continuous)
Hyperalgesia
-lowered threshold of affected tissue to pain (abnormal sensitivity)
Allodynia
-pain produced by normal innocuous (nonirritating) stimulus
Posterior Horn: Rexed's laminae- -I -II (\_\_\_\_\_ \_\_\_\_\_\_) -V
substantia gelatinosa
Discriminative Touch: posterior column- \_\_\_ \_\_\_ pathway -2 pt discrimination -\_\_\_\_ proprioception -\_\_\_\_\_ sense --a- \_\_\_ fiber --collateral to lamina II -decussates in \_\_\_\_\_\_ -relays in \_\_\_\_\_\_ thalamus --ventral posteriolateral nucleus (VPL) -terminates in \_\_\_\_\_\_\_ gyrus
medial lemniscal pathway conscious proprioception vibratory sense a-beta fiber decussates in medulla relays in the lateral thalamus terminates in the postcentral gyrus
Somatotopical
-point-for-point correspondence of an area of the body to a specific point on the central nervous system (brain)
Somatic Sensory cortex on the brain-
postcentral gyrus
Fast Pain: pain temperature crude touch -a-\_\_\_\_\_ fiber -terminates on lamina \_\_ -decussates in spinal cord -\_\_\_\_\_\_\_\_ pathway --relays in lateral thalamus --ventral posterolateral nucleus (VPL) -terminates in \_\_\_\_\_\_ gyrus
a-delta fiber
lamina I
spinothalamic pathway
terminates in postcentral gyrus
Slow Pain: pain temperature crude touch -\_\_\_\_ fiber -lamina \_\_\_ -excitatory interneauron (in L\_\_) -lamina \_\_ -decussates in spinal cord -\_\_\_\_\_\_\_\_ pathway --brainstem reticular pathway -relays in medial thalamus --intralaminar nuclei -many regions of cortex to access where pain is coming from
c fiber
lamina II
Lamina V
spinoreticular pathway
Referred Pain:
- _______ signals from internal structures perceived as pain from surface structures
- -mixing of signals at the level of the :
- –______
- –______
- -no _______ maps of viscera
- represents embryonic origin (diaphragm/heart)
- pattern generators
- grasp reflex
- flexion reflex (uses pain sensors at point of origin, cannot override)
nociceptive signals
signals at the level of spinal cord and brainstem
no somatotopic maps
Itch:
a small subset of _____ ______
-produce and release _______
–results in intense scratching
somatosensory neurons
Nppb (natriutetic polypeptide b)
-axon terminals in lamina I of dorsal horn
Cortical Plasticity
-refers to changes in neural pathways and synapses which are due to changes in behavior, environment and neural processes, as well as changes resulting from bodily injury
Pain Regulation (suppressing/activating) -\_\_\_\_\_ \_\_\_\_\_\_ \_\_\_\_\_ limbic system: -periaqueductal gray - \_\_\_ \_\_\_ \_\_\_ (medulla) -raphe spinal tract (\_\_\_\_\_\_\_) -lamina \_\_
dorsal column collateral
- nuclear raphe magnus
- serotonin (NT- blocks pain)
- lamina II (inhibitory- blocks pain)
The Pain Matrix: areas most commonly activated by pain - - - - - other regions activated: -basal ganglia -cerebellum (motor) -amygdala (fear/anxiety) -hippocampus (reward)
primary somatosensory cortex; S1 secondary somatosensory cortex; S2 insula anterior cingulate cortex dorsolateral prefrontal cortex
Axon Reflex: Triple Response - - -
scratch
1 red line
2 flare
3 wheal (swelling)
Generic Somatic Afferent Pathway: GSA -3 neurons --1 cell body of origin=\_\_\_ \_\_\_\_ \_\_\_ --2 cbo= is \_\_\_\_\_\_\_; axon decussates --3 cbo= \_\_\_\_\_\_ thalamus; to somatic sensory cortex
dorsal (posterior) root ganglion or cranial nerve ganglion
ipsilateral- posterior horn–>medulla (decussation)
lateral
Dermatomes
-the area of skin supplied with afferent nerve fibers by a single posterior spinal root
==overlapping bands of anesthesia (T8 needs T7 to T9)
Sensory Pathway Termination
brainstem retiuclar formation–>periaqueductal gray
cortex
