Cerebrum Flashcards
what are the 4 As of cerebral disorders?
aphasia
agnosia
astereognosis
apraxia
what structures does the diencephalon differentiate into?
the thalamus, hypothalamus, subthalamus, epithalamus, and 3rd ventricle
what is white matter composed of?
fatty myelin
what is grey matter composed of?
cell bodies and dendrites
what is the role of the STN?
basal ganglia importance
stops unwanted movements
big role in motor control
what is the role of the thalamus?
regulates the flow of info to the cortex
what is the role of the relay nuclei of the thalamus?
take info from sensory systems, basal ganglia, or cerebellum to the cerebral cortex
what are the relay nuclei of the thalamus?
motor
sensory
hearing-vision
what is the motor relay nucleus of the thalamus?
VA, VL
basal ganglia and dentate nucleus (cerebellum) to the cortex
what is the sensory relay nucleus of the thalamus?
VPM, VPL
spinothalamic, medial lemniscus, trigeminal pathways
what are the hearing-vision relay nuclei of the thalamus?
MG, LG ???
no idea what this means
what are the 3 nuclei of the thalamus?
relay, association, and nonspecific nuclei
what are the association nuclei responsible for?
emotions, memory, and sensory integration
what does the emotion association nucleus have connections with?
the limbic system
what does the memory association nucleus have connections with?
the hippocampus and prefrontal cortex
what does the sensory integration association area have connection with?
the parietal, occipital, and temporal cortex
what is the role of the nonspecific nuclei?
regulation of consciousness, attention, and arousal
what nuclei is involved in arousal and attention?
intralaminar nucleus
what nuclei is involved in modulation of thalamic activity?
reticular nucleus
what does the intralaminar nucleus connect with?
ARAS and cortical areas
what does the reticular nucleus connect with?
other thalamic nuclei
t/f: the thalamus has a reciprocal connections with the cerebrum
true
what is the main function of the hypothalamus?
homeostasis
what are other fxns of the hypothalamus?
eating, reproductive, and defensive behaviors (thirst, hunger, and sex drive
emotional expression of pleasure, rage, fear, and aversion
regulation of circadian rhythms
endocrine regulation of growth, metabolism, and reproductive organs
activation of the sympathetic NS
what is released by the ant pituitary gland?
growth hormone-releasing/inhibiting hormone
thyrotropin-releasing hormone
corticotropin-releasing hormone
gonadotropin-releasing/inhibiting hormone
prolactin-releasing hormone
what is released by the post pituitary gland?
oxytocin
antidiuretic hormones (ADH, vasopressin)
what is the role of the pineal gland?
sympathetic control
regulate circadian rhythms
influence pituitary gland, adrenal glands, parathyroid, Islets of Langerhans
seasonal affect
what does the pineal gland release?
melatonin
the pineal gland responds well to what meds? why?
psychoactive meds bc it’s not in the blood brain barrier
what are the s/s of a thalamic lesion
contra loss of sensation (most severe for discriminitive sensations w/others for affected as much )
thalamic pain syndrome (rare)
lateropulsion
what is the role of the intralaminar nuclei?
alertness and consciousness
what conditions affect the intralaminar nuclei?
PD, TBI, and thalamic stroke
pituitary tumors make up __% of all intracranial neoplasms
10
t/f: pituitary tumors are malignant
false, they are benign and slow growing
what are the s/s of pituitary tumors?
droppy eyelids, diploplia, blurry vision, irregular menstruation, sexual dysfxn from hypo/hyperactive pituitary or compression of it
what are the 3 categories of subthalamic white matter?
projection fibers
commissural fibers
association fibers
what are projection fibers?
subcortical afferent projections to the cortex
efferent fibers from the cortex to the SC
most fibers go through the internal capsule to the corona radiata
corticospinal tract
what makes up the anterior limb of the internal capsule?
corticopontine fibers, frontopontine fibers, other corticofugal (from the cortex) fibers
what makes up the genu of the internal capsule?
fibers to the CN motor nuclei and reticular formation
what makes up the posterior limb of the internal capsule?
corticospinal and thalamocortical projections
what is the role of the posterior limb of the internal capsule?
conveys omatosensory, visual, auditory and motor info to the cortex
where in the internal capsule is there the most amount of projection fibers?
in the posterior limb
what are commissural fibers?
connect homologous areas across the cerebral hemispheres
connect the same areas in both hemispheres
what is the largest group of commissural fibers?
corpus callosum
what does the anterior commissure link?
L and R temporal lobes
what are association fibers?
connect cortical regions w/one hemisphere
not crossing bw L/R hemispheres
what do short association fibers connect?
adjacent gyri
what do long association fibers connect?
lobes w/in one hemisphere
what does the uncinate fasculus (association fibers) connect?
frontal and temporal lobes
what does the sup longitudinal fasciculus (association fibers) connect?
all lobes
what does the inf longitudinal fasciculus (association fibers) connect?
temporal and occipital lobes
what does a lesion to the internal capsule cause?
contra impairment to voluntary movement (corticospinal tract lesion)
contra loss of conscious somatosensation (thalamocortical tract lesion)
loss of conscious vision if the lesion extends posteriorly from the contra visual field
even a small lesion has severe deficits
what does a lesion in the corpus callosum cause?
problems with imitation, bimanual tasks, apraxia (voluntary automatic dissociation)
what is usually done for a lesion in the corpus callosum?
callosotomy (surgical cutting of the corpus callosum)
what are the fxns of the cerebral cortex?
higher order sensory processing
motor planning
language processing
visual-spatial orientation
behavior
judgement
abstract thought
what is the fxn of the primary sensory cortex?
simple sensory discrimination (intensity, quality)
what is the fxn of the secondary sensory cortex?
recognition of sensation
what is the fxn of the association cortex?
goal selection, planning, monitoring
interpretation of sensation
emotions, memory processing
what is the fxn of the motor planning areas (premotor and supplementary motor areas included)?
movement composition, sequencing
what is the fxn of the primary somatosensory cortex?
discrimination of shape, texture, or size of an object
what does a lesion in the primary somatosensory cortex cause?
loss of tactile localization and conscious proprioception
what is the fxn of the primary auditory cortex?
conscious discrimination of loudness and pitch of sounds
what would a lesion of the primary auditory cortex cause?
loss of localization of sounds
what is the fxn of the primary visual cortex?
distinguishing among the head positions and head movements
contributes to perception of vertical
what would a lesion in the primary visual cortex cause?
change in awareness of head position and movement and perception of vertical
lateropulsion
what is perception?
interpretation of sensation into meaning
perception is the interaction among the ___, ____, and ____
brain, body, environment
what is involved in perception?
past experiences, motivation, expectations, and selection of pertinent sensory info
what areas of the cerebrum participate in perception?
primary sensory, secondary sensory, and association areas
what is the fxn of the secondary somatosensory cortex?
stereognosis and memory of the tactile and spatial environment
what would a lesion of the secondary somatosensory cortex result in?
astereognosis
what is the fxn of the secondary visual cortex?
analysis of motion, color
recognition of visual objects
understanding of visual spatial relationships
control of visual fields
what would a lesion of the secondary visual cortex result in?
visual agnosia or optic ataxia
what is the fxn of the secondary auditory cortex?
classification of sounds
what would a lesion to the secondary auditory cortex cause?
auditory agnosia
what is agnosia?
inability to recognize objects when using a specific sense, even though discriminitive ability w/that sense is intact
what is astereognosis?
lesion in S2 (secondary somatosensory cortex)
inability to ID an object by touch and manipulation
what is visual agnosia?
lesion in ventral V2 (secondary visual cortex)
inability to visually recognize an object
prosopagnosia
what is prosopagnosia?
type of visual agnosia where you can’t recognize people’s faces but can recognize them by their voice and can tell when facial expression are positive/negative
what is auditory agnosia?
lesion in A2 (secondary auditory cortex)
inability to recognize sounds (hemisphere specific)
L-unable to understand speech
R-unable to interpret environmental sounds
if there is a lesion of the L hemisphere causing auditory agnosia, what is the deficit?
unable to understand speech
if there is a lesion of the R hemisphere causing auditory agnosia, what is the deficit?
unable to interpret environmental sounds
what is optic ataxia?
inability to use visual info to direct movements despite intact ability to visually ID and describe objects
lesion in the dorsal visual stream
what does the dorsal visual stream do?
guides motion
awareness pathway
is the ventral stream the “what?” or “where?” pathway?
“what?” pathway
is the dorsal stream the “what?” or “where?” pathway?
“where?” pathway
does ventral stream dysfxn result in visual agnosia or optic ataxia?
visual agnosia
does dorsal stream dysfxn result in visual agnosia or optic ataxia?
optic ataxia
where is the primary motor cortex located in the brain?
in the precentral gyrus anterior to the central sulcus
where is the origin of the corticospinal and corticobrainstem tracts?
the primary motor cortex
what does the primary motor cortex control?
contra voluntary movements and movement fractionation
selective motor control
what are the inputs to M1?
somatosensory info relayed by the thalamus from S1
motor instructions from the motor planning areas
what are the deficits associated with a lesion in the primary motor cortex?
contra paresis and loss of selective motor control (fractionated movement)
dysarthria
dysphagia
what is spastic dysarthria?
UMN lesion (tracts)
harsh, awkward speech production
what is flaccid dysarthria?
LMN lesion (nuclei)
CN 9, 10, 12
breathy, soft/weak, and imprecise speech
what are the cortical motor planning areas?
premotor area (PMA)
supplementary motor areas (SMA)
inf frontal gyrus
what is the role of the PMA?
stabilizes trunk and girdle muscles in prep for limb movement
selects and initiates some movements and goal directed actions
anticipatory postural adjustments
what is the role of the SMA?
motor initiation (opening eyes, head)
plans bimanual/sequential movements
important in faster/more complex movements
orientation planning
what is the role of the inf frontal gyrus?
Broca’s (L): motor programming of speech
emotional/social/spatial (R): planning nonverbal communication
what are the areas of the inf frontal gyrus?
Broca’s areas (L) and its corresponding area on the R (nonverbal)
what is Broca’s area responsible for?
planning movement of the mouth for speech
motor programming of speech
what would a lesion in the premotor cortex result in?
apraxia
what would a lesion in the supplementary motor areas result in?
apraxia
what would a lesion in Broca’s area result in?
broca’s aphasia
L hemisphere lesion
difficulty with verbal communication
what would a lesion in the inf frontal gyrus in the hemisphere dominant for emotional, social, and spatial processing result in?
difficulty producing nonverbal communication
R hemisphere lesion
what is motor agnosia?
loss of knowledge of how to perform a skilled movement despite normal strength, sensation, coordination, and knowledge of the task
damage to what areas can cause motor agnosia?
PMA, SMA, inf parietal lobe
what is ideomotor apraxia?
automatic-voluntary dissociation
can automatically perform a motion but unable to when asked to do it voluntarily
what is ideational/conceptual apraxia?
difficulty performing any multistep motor activity
inability to access an appropriate motor activity (toothpaste on after brushing teeth, shoes b4 socks)
what is constructional apraxia?
inability to comprehend the relationship of parts of the whole
side specific
L=oversimplifying/omitting details
R-L side neglect
what does constructional apraxia of the L result in?
oversimplifying a drawing or omitting details
what does constructional apraxia of the R result in?
L sided neglect (will only draw on one side of the clock)
what is motor perseveration?
uncontrollable repetition of a movement associated with greater neural damage
what are the disorders affecting cerebral function?
cerebral stroke
tumor
epilepsy
what is a meningioma?
usually benign brain tumor in the meninges
most common primary brain tumor
what is a glioma?
mostly malignant brain tumor from the glial cells
astrocytoma, oligodendroglioma, glioblastoma
what is an astrocytoma?
tumor of the astrocytes
sometimes benign
usually in young adults and children
what is an oligodendroglioma?
tumor from oligodendrocytes
what is a glioblastoma?
a dangerous type of glioma
what is a medulloblastoma?
from the neural ectoderm cells
most common malignant brain tumor in children
usually arises from the cerebellum
what is an adenoma?
tumor in glands/epithelial tissues
pituitary tumor is most common and cuases visual problems, nausea, and vomiting
what is an acoustic neuroma?
tumor the Schwann cells around CN 8
causes hemiparesis, ataxia, and dysarthria
what are the common s/s of a brain tumor?
Motor: hemiparesis, ataxia, dysarthria
Sensory: sensory deficits
Visual: hemianopsia, visual-perceptual deficits
Communication: aphasia
Executive function: memory and motor learning deficits, apraxia, behavioral disturbances
GI: problems with bladder control
what is epilepsy?
sudden attacks of excessive cortical neuronal discharge interfering with brain fxns causing seizures
involuntary movements, disruption of autonomic regulation, illusions, and hallucinations
what are the causes of epilepsy?
channelopathies
tumor
infection
stroke
TBI
neurodegenerative disease
febrile
what are the two types of generalized seizures?
absence and tonic clonic
what are absence seizures?
brief loss of consciousness w/o other motor symptoms
what are tonic clonic seizures?
motor
involves tonic contraction of skeletal muscle (shaking of muscles)
muscles tense up and start shaking
what is an epileptic emergency?
if the seizures last more than 5 minutes, person has diabetes, is pregnant, or has new onset seizures
normally, tonic clonic seizures last ___ minutes and the patient is confused upon awakening
1-2
