ORG exam 1 Flashcards
yorkston model of disorder
motor plan–>motor planning–>apraxia
speech movts–> speech execution–>dysarthria
duffy’s model of disorder
cognitive linguistic processes–> motor speech programming–> neuromuscular execution
each with a neurological element
cell body
soma, gray matter
contains normal cellular elements (mitochondria, ER, nucelus, neurofibrils)
mitochondria
– produce ATP – adenosine triphosphate- ENERGY- important for muscle contraction
dendrites
aff projection to receive input and send to cell body; multiple, short
axon
eff projections sending signal away from cell body to other cells
single axon; longer, some up to 2 meters in length;
increased diameter of axon – increase speed that signal propagates
myelin
white matter, fatty substance- part of the oligodendrocyte that wraps around the axon and is critical to sending signal along axon- wont charge properly without
axon hillock
junction of cell body and axon
nodes of ranvier
points along the axon that are not covered with myelin; gaps; very important for transmission of impulses along the axon
terminal button
end of axon
synapse
area of connection between one neuron (axon) and another cell (neural or muscular)
space where one neuron influences/communicates with following cell thru an electrochemical process
synaptic cleft
gap between the two adjacent cells
types on synapses
axoaxonic
axodendritic
axosomatic- cell body
neuromuscular
neurotransmitters
Chemicals stored in synaptic vesicles are dumped into synaptic cleft to affect transmission of signal to next cell
excitatory - may excite – turn on the next neuron/muscle fiber – e.g. acetylcholine (critical at neuromuscular junction)
inhibitory - may inhibit of impede activity in next neuron – e.g. dopamine
types of neurons
many different types perform specific neural functions or are located in specific brain regions
unipolar, bipolar, multipolar-refers to the axon structure of the neuron e.g. within multipolar
Motoneurons> SC to skeletal muscles
purkinje cells>cerebellum
pyramidal cells>cerebral cortex to SC/brainstem
axon bundles
white matter
PNS: nerves: aff sensory, eff motor, mixed
CNS: tracts/fascicles
cell body bundles
gray matter
PNS: ganglia
CNS: nuclei
CNS neuroglia
supportive tissue,Can proliferate into tumors
Astrocytes surround neurons and provide protection, regulate the extracellular fluids
Oligodendrocytes surround neurons and make myelin to surround the axons, one to many axons
Microglial cells- phagocytes i.e. remove debris and extraneous substances
Ependymal cells-form the epithelial lining of the innermost cavity of the neural system
provides protection i.e. is a barrier to allowing foreign substances to affect the neurons
also secrete and absorb CSF
PNS neuroglia
Satellite cells are like astrocytes
Schwann cells like oligodendrocytes- surround neurons and create myelin
- play role in regeneration of PNS nerves
Neural resting potential
Always level of electrical activity in cell from ions
-60 to -70 at rest
Permeable membrane k+ out Cl- in
Gradient ??
Neural conduction: action potential
Electrical processes that generate more positive activity:
Depolarization to -50mv, membrane changes, na comes in and cell becomes positive
Sends signal along axon to next neuron
Propagation - all or noting saltatory
Synapse- chemical event takes place
Summation
Spatial- simultaneous activation by multiple synapses
Temporal - sequential activation from same synapse over time
Speed factors DMR
Diameter of axon: larger = faster
Myelination= faster
Refractory period: cell cannot fire again for roughly 10 ms, or until equilibrium reestablished
Classification of nerves A-E P-C
Function
Aff- sensory, toward cell body or CNS
Eff- Motor, away from cell body or CNS
Location
CNS- protected by cranium and vertebral column, brain SC
PNS- outside bony confines- 12 cranial 30 spinal, autonomic (sympathetic- thoracolumbar and parasympathetic- craniosacral), visceral aff
Brain: frontal lobe BA SM
Broca’s area– l cerebral hem, part of inferior frontal gyrus, speech motor planning and programming
SMA- supplementary motor area- left hemisphere , initiating and preparation of movt, including speech and thought- brodman 6
Parietal lobe PS
Primary sensory cortex- post central gyrus
contralateral sensation- interpret touch, pain, temp
somatotopic map
cerebral white matter
projection fibers- aff and eff
upper motor neurons
corticospinal- brain to spine, corticobulbar brain to head
upper sensory neurons
cerebral white matter pathway
Bulbar: C>CR>IC>CP>B>NCaptain Crunch Really is Captain Crunch promised Brian nervously.
Spinal: C>CR>IC>CP>P>S>Mn Captain Crunch Really is Captain Crunch promised Pete speedily munching.
Cortex–>
Corona Radiata - large radiation of projections fibers just below cerebral cortex
Internal Capsule - projection fibers converge tightly into band of white matter – through basal ganglia
Cerebral Peduncles/crus cerebri - down thru to brainstem and SC musculature below – midbrain level
–corticobulbar tracts synapse in brainstem nuclei and innervate CN
–corticospinal tracts continue down to
–Pyramids - crossing/decussations of corticospinal fibers in medulla leading to SC where synapse on motoneurons in ventral horns
subcortical gray matter: basal ganglia (nuclei) C LN PGP Clean LeoNard’s PiGPen
also called corpus striatum =caudate+putamen should be called “nuclei”- looks like blue tooth
includes
1) caudate - bilateral, long tailed structure which ends at the amygdala
2) lenticular nucleus - nut-shaped structures at front of caudate; consists of
—putamen
—globus pallidus - two segments (internal, external)
function:
—involved in integrating complex motor activity such as walking, posture, balance, and of course, speech;
—regulating size direction etc i.e. inhibiting unwanted motor activity
subcortical gray matter: thalamus SRI SpNu
sensory relay and integration center- does not control movt directly but can affect if damaged
walnut-sized oval masses deep within each cortex; more mesial than BG
each consists of many different nuclei specialized for different functions e.g. memory, language, sensory, motor, attention and arousal
-the two can be connected to one another
subthalamic nuclei
-less apparent nuclei below thalamus that are involved in motor system
midbrain - mesencephalon SN RN CP
substantia nigra - just deep to peduncles – dark gray/black, important for providing dopamine to basal ganglia directly above
red nucleus - round nucleus that is another structure involved in motor activity via cerebellum
cerebral peduncles - anteriorly – white matter, continuation of internal capsule so important motor pathway to SC
cerebellum - hindbrain Celebrate smooth coordinator ip
posterior inferior part of brain; more, smaller convolutions divided into two hemispheres with cortex of gray matter and interior regions of gray and white matter
fn: integrates and coordinates smooth, synergistic limb movts, balance, posture, and gait (wide-based gate); timing
* ipsilateral control*
pons - metencephalon VCP DBN
Pound Veronica’s cereal peanuts, and Dori’s bready naan.
anterior hump at top of brainstem
fibers connect to the cerebellum
ventral portion - contiguous with cerebral peduncles to pyramids
dorsal portion - brainstem nuclei of some CN that exit at pons, nuclei of reticular formation, and ascending and descending sensory and motor tracts
medulla oblongata P D-NCG UP-ICP RF
Model Pyros, dolphins need coital grace, underperforming models infest cereal peanuts.
lowermost portion of brainstem
contiguous with SC below
contains
*pyramids - decussation
*dorsal portion of medulla
—nucleus cuneatus and nucleus gracilis -cell bodies for sensory tracts coming up from SC
*upper posterior medulla
—inferior cerebellar peduncles - carrying info to cbl
*reticular formation- cardiac and vasomotor life fn centers of MO (HB, respiration, wake)–coma
direct activation pathway - pyramidal tract - upper motor neuron UMN
Bulbar: C>CR>IC>CP>B>NCaptain Crunch Really is Captain Crunch promised Brian nervously.
Spinal: C>CR>IC>CP>P>S>Mn Captain Crunch Really is Captain Crunch promised Pete speedily munching.
2 UMN branches
corticobulbar tract: to cranial nerves
corticospinal tract: to spinal nerves
origin - pyramidal cells in primary motor cortex, but also cells in premotor cortex and primary sensory cortex (topographic organization along the strip)
path: corona radiata> internal capsule> cerebral peduncles (aka crus cerebri)>
to Brainstem/corticobulbar (contra or ipsi) > CN
OR
to SC/corticospinal- (decuss=contra)> ventral part of SC (motor neurons)
function: critical for voluntary, skilled, discrete, rapid movts– including speech movts
indirect activation pathway - extrapyramidal system: reticular CoRe CbRe ReSp: Indirectly, Corey Celebrated Respect.
second source of input to LMNs/final common pathway
multiple synapses along its pathway
origin - cortex - motor, premotor, and sensory cortex
Reticular pathways:
–1. corticoreticulo fibers: cortex down to reticular formation nuclei in brainstem
–2. cerebelloreticular
–3. reticulospinal fibers: brainstem down to motoneurons
probably involved in muscle tone, some fibers are actually inhibitory to muscle activity
indirect activation pathway - extrapyramidal system: Red nucleus CoRu RuSp: Indirectly, Cole ruined Ruth’s speech.
corticorubral fibers: cortex to red nucleus
rubrospinal tract: red nucleus to spinal motor neurons
important for flexion activity probably also in speech muscles
indirect activation pathway - extrapyramidal system: Vestibular VeSp Indirectly, Vera sparkled.
vestibulospinal fibers: vestibular nuclei in brainstem down to SC **function overall regulates reflexes (so certain reflexes don’t occur), muscle tone resulting from a certain amount of input at all times- must be in balance and the upper pathway inhibits, posture so that direct pathway can accomplish its goals
Indirect pathway damage DeCo Flex DeCe Flop
decorticate posture - lesion of upper portion of indirects/directs - corticoreticular/rubral pathways - allow fibers from rubral/reticular/vestibular to fire uninhibited leading to extensor activity in the legs and flexion activity in the arms (BROCA arm)
decerebrate posture - lesions from midbrain to medulla now ends the flexion activity and see arm extensor activity as well (floppy)
- localized reflexes unmodified from input above
- Speech problems not language- dysarthria not aphasia
motor pathways DA IA CBC BGC FC DanA InitiAted CeleBrating Christmas BaGs Chock Full of Candy.
1) “direct activation pathway” - pyramidal system - upper motor neuron UMN
2) “indirect activation pathway” - extrapyramidal system
3) “cerebellar control circuit”- coordination/timing
4) “basal ganglia control circuit”- size of movt
5) “final common pathway” - lower motor neuron LMN
basal ganglia control circuit
CSPTC But guys- can strong puppy tear can? PSNP Potentially some nicks possible. STNGP. STaND Guard, Puppy Stain.
no direct contact with motoneurons below;
exert their influence in integration/regulation and coordination of movt via complex interactions among cortical/subcortical structures
Circuits, excitatory and inhibitory:
*cortico-striato-pallido-thalamo-cortical loop
–sub-circuit 1: striatonigral (putamen-substantia nigra-putamen) *dopamine (inhibitory)
–sub-circuit 2: subthalamic nucleus - globus pallidus
Should be a balanced system: neurotransmitter activity in striatum is critical– acetylcholine (excit) and dopamine (inhib), also gaba (inhib)
function: critical for normal muscle contraction and posture allowing for voluntary movts to proceed smoothly
–regulate amplitude, velocity, and initiation of movts
–regulates intended movts, dampen unwanted movts
–in speech, the basal ganglia circuit actually seems to “dampen” movts
cerebellar control circuit CC PrMo PreMo Cbl Co
PriMe or PreMium Celebration Costs.
hemispheres control movts on ipsilateral sides of body-because info goes from L cbl up to R cortex which controls L body
corticocerebellar loop: primary motor and premotor to cbl
cbl via red nucleus and thalamus back to cortex
(cortico-[pons]-cerebellar-rubro-thalamo-cortical)
fn in speech:
role in anticipating intended speech movts and providing feedback from periphery
temporal regulation of sensory and motor info
inhibitory role in movt to refine poorly formed cortical movts, smoothing and coordinating movts
ipsilateral control of movt
final common pathway = lower motor neuron (peripheral nervous system)
12 pairs of CN and their ganglia
31 pairs of spinal nerves and their ganglia; dorsal and ventral roots
nerve = collection of nerve fibers
aff - carry impulses from sensory structure toward CNS
eff - carry impulses from CNS to end structure e.g. muscle
mixed - some have both types of nerve fibers
Cranial nerves
emphasis on CNs of speech
designated by roman numerals in order of which they leave brainstem from top to bottom
motor CN - cell bodies in brainstem nuclei
sensory CN - cell bodies in ganglia at sensory organ
cranial nerve V - Trigeminal S:FMJ M:Ch TVP-TT SH
largest CN; complex, important nerve for our interests
”trigeminal” because has 3 main branches
bilateral innervation
Sensory and motor- bilateral
Sensory: face, mouth and lower jaw, *anterior 2/3 of tongue (Dentist blocks CN 5)
Motor:
muscles of mastication: medial and lateral pterygoids, masseter, buccinator
muscles of soft palate - tensor veli palatini (pulls down)
tensor tympani - in middle ear
suprahyoid muscles: mylohyoid, anterior belly digastric
Cranial Nerve VII - Facial S:TTS M:StDiSty EFNM
large, complex sensory-motor nerve important for aspects of speech and swallowing
upper facial muscles - bilateral cortical input
lower facial muscles - uni/contralateral
cortical input speech
sensory: **anterior 2/3 of tongue - taste, touch - skin around ear
Motor:
stapedius muscle in middle ear
posterior belly digastric
stylohyoid
muscles surrounding eye
muscles of face and nose
buccinator, orbicularis oris, lower lip muscles, platysma
also motor input to mucuous membrane glands of nose and palate
**cranial nerve VIII - Vestibulocochlear - Auditory
bilateral sensory input > heschl’s gyrus
cochlear portion: arises from cells in spiral ganglion of cochlea, enter brainstem at lateral most pontomedullary junction, courses up to temporal cortex of brain via a number of bilateral synapses
Lesions of:
LSN - unilateral deafness e.g. acoustic neuroma/schwannoma
USN - no symptoms because of bilateral activation of cortex by cochlear nerve
vestibular portion: equilibrium and balance, fibers arise in vestibular labyrinths of the inner ear
lesions:
vertigo - sense that the world is rotating
nystagmus - spasmodic eye movements
nausea and vomiting common with these
**cranial nerve IX - Glossopharyngeal S: TTTETM M: Gag
bilateral innervation motor: stylopharyngeus muscle and superior constrictor eff to parotid (salivary) gland part of middle pharyngeal constrictor Sensory: **tactile sensation posterior 1/3 of tongue, **taste - posterior 1/3 of tongue external ear skin internal tympanic membrane mucous membrane of pharynx, soft palate, posterior tongue mediates pharyngeal gag reflex **but not all people will have one contributes to initiating swallow reflex
cranial nerve X- Vagus- motor: PhMu SLPi RLPh
latin for wandering - as in vagabond bilateral innervation Motor Pharyngeal branch: muscles of pharynx (except stylopharyngeus) palatoglossus muscle of tongue levator veli palatini
Superior laryngeal branch:
cricothyroid (pitch changing) tense thin elongate
Recurrent laryngeal branch:
innervates all other muscles of larynx- PHONATION arytenoids, etc
glands of pharynx, larynx, thoracic and abdominal viscera
*left recurrent loops under aorta
**cranial nerve X- Vagus- sensory: LTETh EAM
Sensory larynx, trachea, esophagus and thorax, and abdominal viscera skin at back of ear and ext aud meatus external tympanic membrane pharynx involved in palatal gag reflex Cough, clear throat
**cranial nerve XI - Spinal Accessory
LVP StClMa TPZ
bilateral innervation
motor - spinal portion
Levator veli palatini??
Sternocleidomastoid- turn head
Trapezius- shrug shoulders
**cranial nerve XII - Hypoglossal
primarily motor nerve
all intrinsic and extrinsic tongue muscles except palatoglossus
also some strap muscles of neck
**contralateral innervation - i.e. right cortex controls left tongue muscles and vice versa
spinal cord
extends from C1 to about T11
inferior portion - ends as conus medullaris
cauda equina -Sen N at bottom fan outward looking like a tail
transverse section: gray matter center
dorsal horns - aff or sensory neurons into SC
ventral horns - associated with eff motor neurons from SC to muscles
SC enlarged in two regions: cervical and thoracic where many neurons involved in supplying muscles of upper and lower limbs
white matter surrounding tracts of aff and eff fibers running to other parts of SC or up toward brain
e.g. pyramidal tract - continuation of the corticospinal motor tract from all the way up at motor cortex
spinal nerves
31 pairs
formed by merging of dorsal and ventral roots
divide into dorsal and ventral ramus - which has both afferent and efferent fibers
motor fiber cell bodies - in ventral horn of spinal cord
sensory fiber cell bodies - in ganglia at sensory organ
8 cervical (c 1-4 phrenic nerve– diaphragm)
(C5-8 and T1 -brachial plexus -chest & upper limb)
12 thoracic (intercostal nerves - from T1-11 -innervate muscles of the ribs; T6-12 supply abdominal muscles)
5 lumbar
5 saccral
1 coccygeal
Spinal cord motor neurons
alpha motoneurons - influenced by the pyramidal system
gamma motoneurons - influenced by the extrapyramidal system
muscle spindle afferent - afferent fiber back to the motoneuron to complete a reflex arc
this interaction is the way certain reflexes can occur based on feedback from the afferent fiber to the motoneuron
Sensory in, motor out
