neuro 1 Flashcards
proprioception
ability to recognize position
kinesthesia
ability to recognize movement
muscle spindle
proprioceptor that detects the length, velocity, and acceleration of a muscle
afferent:
sensory
1a afferent sense…
senses overall length and velocity/acceleration
2 afferent sense…
senses overall length only
nuclear chain fibers are contacted by
both 1a and 2
nuclear bag fibers are contacted by
only 1a
gamma motoneurons function
make the muscle spindle more or less sensitive by pre-tensing or relaxing the equatorial region
in the stretch reflex _______ neurons synapse directly on _____ resulting in recruitment of motor pools
1a afferents synapse on alpha motoneurons
intramural fiber
mm. tissue within the spindle
adequate stimulus
the specific type of stimulation that a receptor is able to respond to
ligand gated means
opened by neurotransmitter
are cells negative or positive at rest?
negative
depolarization is
making the inside of the cell more positive, excitatory effect, lets Na+ flow into the receptor
receptor potential–>
generator potential
generator potential is located
at the first node
rate coding
larger the generator potential the more quickly he trigger zone makes action potentials
stronger stimulus = higher frequency of APs
population coding
more receptors activated –> larger area was stimulated
temporal coding
action potentials only generated while stimulus is present
adaptation
a decrease in sensitivity to a maintained stimulus
1a are fast adapting (start and stop = movement), group 2 are slow adapting (current state=position)
pacinian corpuscles are ____ adapting, while merkel’s discs are _____ adapting
rapid, slow
ionotropic receptors vs. metabotropic
ionotropic: act directly on ion channel
metabotropic: act indirectly through second messenger
action potential sequence
at rest permeable to K+ --> Na+ floods in --> -50mV threshold --> Na+ channels open --> \+30 mV --> K+ channels open --> K+ exits and reverses potential --> meanwhile Na+ channels close --> back to -75
refractory period
time after AP that another AP is impossible or unfavorable
larger axons have _____ propagation of APs
faster
EPSP vs. IPSP
excitatory vs. inhibitory postsynaptic potential
EPSP: increases permeability to Na+ –> depolarization
IPSP: makes depolarization more difficult by increasing Cl- or K+ permibalility
IPSP goes to soma to stop EPSP on dendrites
neuromodulator
modulates the effect of neurotransmitters on the postsynaptic cell, act at a distance away from the synaptic cleft
oligodendrocytes are found in the _____ (myelin)
CNS
Schwann cells are found in the _____ *myelin)`
PNS
astrocyte function
help buffer synaptic environment, scar tissue
microglia function
neuroimmune cells of the CNS
excitotoxity from what?
glutamate
tract vs. pathway
tract axons travel together in CNS, no synapse
pathway: route in nervous system for relative direct transfer of info, usually one or more synapses
high vs. low fideltiy
high fidelity = details about location of stimuli
DCML conveys Information of….
discriminative touch and proprioception
spinothalamic tract conveys ….
pain and temp
DCML decussates in the ______
medulla–> medial lemniscus
fasciculuc gracilis
medial, legs
cuneate fasciculus
lateral, arms
primary sensory cortex Brodman’s areas…
3a, 3b, 1 and 2
area 2 integrates….
sensation across modalities
area 5 integrates…
sensation across body parts
area 7 integrates…
intrapersonal with extra personal space
also receives visual and auditory info
left neglect is from damage to areas ___ and ____
5 and 7
fast pain is carried by
small, myelinated a-delta fibers
slow pain is carried by
small, unmyelinated C fibers
function of spinomesencephalic
turning eyes and head towards pain
go to superior colliculus and periaqueductal gray
function of spinoreticular
modulates arousal, attention, and sleep/wake
go to brainstem reticular formation
function of spinolimbic
responsible for affective response to pain
go to anterior cingulate cortex and posterior insula
receptive field
specific area where stimulus will be perceived
Golgi tendon organs sense ______ generated tension in muscle
actively
Golgi Mazzoni receptors sense
intra articular pressure
Ruffini (spray) recepetors sense
articular capsule stretch
substance P
released by nociceptors into tissues, increases nociceptor sensitivity, makes mast cells release histamine, increases permeability of venues –> edema
primary hyperalgesia
heightened sensitivity in damaged tissue
secondary hyperalgesia
heightened sensitivity in surrounding tissue
referred pain comes from
shared second order neurons
raphespinal tract purpose
its a descending system (part of lambic) from the periacquaductal gray that releases serotonin in the substantial gelatinous to decrease pain transmission
5 mechanisms of chronic pain
- ectopic foci
- ephaptic transmission
- central sensitization
- structural reorganization
- altered top-down modulation
ectopic foci
injured nerves fire spontaneously
ephaptic transmission
injured nerves release irritatnts
central sensitization
irritated 2nd and 3rd order neurons keep firing after intense pain experiences
structural reorganization
pathways adapt and alter so increased pain is alway part of the system
altered top-down modulation
impaired ability for central structures to play their normal regulatory role
lamina 9 =
motor pools, located in ventral horn
where are lateral horns evident?
cervical and lumbar enlargements
lamina 7 =
intermediate zone
lamina 8 =
ventromedial gray
motor pool actions based on location
anterior: extensors
posterior: flexors
medial: proximal
lateral: distal
which muscle fibers are activated first?
slow twitch (type 1) because they are small fibers (easier to excite)
length constant is _____ proportional to conduction velocity
directly
merkel’s disk
touch/pressure, slow adapting
meissner’s corpuscle
light touch/vibration (lower Hz), rapid
free nerve endings
temp/pain
pacinian corpuscle
touch/vibration (higher Hz)
Ruffini (spray) endings
stretch/pressure, rapid
fast pain is carried by …
small, myelinated a-delta fibers
slow pain is carried by…
small, unmyelinated C fibers
only 1a afferents can monosynaptically connect to alpha motoneurons (T/F)
T
function of cingulate cortical area
motivational and emotional aspects of movement
function of premotor area
motor planning and preparation, guided by vision
cerebellum
area 5 –> body in space
area 7 –> interacting with world
function of Supplementary motor area
motor planning and preparation, BUT INTERNALLY GUIDED, speech
parasympathetic control comes from…
craniosacral outflow from vagus nerve (sacral spinal cord)
Arnold-chiari malformations (2 types)
type 1: brainstem malformed (maybe asymptomatic), may lead to hydrocephalus
type 2: cerebellum herniates through foramen magnum, symptoms at birth
explicit (declarative) learning has two types
semantic: facts
episodic: events
types of implicit (non-declarative learning)
priming
procedural
associative (operant and classical)
non associative (habituation and sensitization)
dysdadiokinesia
impaired rapid alternating movement
cerebellum deficits are ipsilateral (T/F)
TRUE
guillian barre syndrome
PNS demyelination (Schwann cells)
Multiple sclerosis
CNS demyelination (oligodendrocytes)
ACh has what type of function on basal ganglia?
inhibitory
with Huntington’s their ACh is faulty
